| Id | Authors | Title | Year | Subject | Source | Location | Language | Held As | Dave's Notes | Dave's Quotes |
| 172 | Aballay, E. & Insunza, V. | Evaluación de plantas con propiedades nematicidas en el control de Xiphinema index en vid de mesa cv. Thompson seedless en la zona central de Chile | 2002 | Compost & Biocontrol | Journal | Agric Téc; 62 (3); 357-365 | Spanish | Hardcopy:Full; Wordperfect:Full | Field expt. to test the capacity of various plants to suppress the effect of a virus carrying nematode species on vines. The plants tested included rape, thyme and two spp. of marigold (1 Calendula sp. and 1 Tagetes sp.). Only rape was effective in suppressing the nematode | |
| 502 | Abbasi, M.K. & Adams, W.A. | Assessment of the contribution of denitrification to N losses from compacted grassland soil by NO3- disappearance and N2O production during anaerobic incubation | 1999 | Greenhouse Gases; Soil N Dynamics | Journal | Can. J. Soil Sci.; 79 (1); 57-64 | English | Hardcopy:Partial | Lab. expt. to xmeasure the denitrification capacity of soils and the N2O emissions at different depths, using soil samples taken from a wet clay loam under grazed pasture. The ratio between N2O-N evolved and NO3--N lost was greater than 2:1, indicating that not all of the NO3- lost was accounted for as N2O. This may have been because (1) some N2O remained trapped in the soil, (2) some N2O was reduced to N2 or (3) microorganisms (in anaerobic condition and with available C) might be able to (store NO3- in excess of their immediate needs. | Denitrification occurs when nitrate is present in anaerobic or nearly anaerobic microsites.; Compaction .. impairs drainage, which leads to anoxic conditions .. surface wetness coupled with high levels of root-derived OM promotes .. denitrification. |
| 499 | Aber, J.D. & Melillo, J.M. | Nitrogen immobilisation in decaying hardwood leaf letter as a function of initial nitrogen and lignin content | 1982 | Lignin and CBW; Soil N Dynamics | Journal | Can. J. Bot.; 60; 2263-2269 | English | Hardcopy:Full | Modelling the N immobilisation of litters of varying lignin and N content | The highest immobilisation rates .. occur in litters high in both lignin and N .. because total immobilisation increases with lignin content, while rate of decay increases with N content.; early successional and understorey species plus symbiotic N fixers have high N concentrations; and late successional species generally associated with poor site conditions have high lignin concentrations. |
| 878 | Ackermann, R. | Maismulchsaat im langjährigen Vergleich | 2002 | Cover Crops; Tillage | Journal | Landwirtschaft ohne Pflug; 1; 15-17 | German | Hardcopy:Full | 7-year field expt. to study the effect of cultivation (zero tillage, rotovation or ploughing) on conventionally grown maize crops with different winter cover crops (grown on weeds/volunteer crops, mustard or winter rye) and different weed control (chemical, mechanical or a combination of the two). Mustard gave the highest soil inorganic N content in the spring. winter rye the lowest. Zero tillage gave the highest soil inorganic N content after harvest. Reduced tillage with winter rye gave the highest soil moisture content in the spring, conventional tillage the lowest. The DM and energy yields were lowest with zero tillage, with mustard and with purely mechanical weed control. | |
| 1693 | Ackermann, R. | Bodendecker halten Wasser im Boden | 2002 | Cover Crops; Tillage | Journal | Landwirtschaft ohne Pflug; 2; 13-15 | Hardcopy:Full | |||
| 1695 | Ackermann, R. | Alterunkrautung vor der Saat bekämpfen | 2002 | Cover Crops; Tillage | Journal | Landwirtschaft ohne Pflug; 3; 17-18 | German | Hardcopy:Full | ||
| 1696 | Ackermann, R. | Maismulchsaat rechnet sich! | 2002 | Uncategorised | Journal | Landwirtschaft ohne Pflug; 5; 25-27 | German | Hardcopy:Full | ||
| 415 | Adams, G. & Wall, D. | Biodiversity above and below the surface of soils and sediments: linkages and implications for global change | 2000 | Miscellaneous | Journal | Bioscience; 50 (12); 1043-1048 | English | Hardcopy:Full; Wordperfect:Full | Review of existing knowledge on the interaction between above - and belowground organisms and the possible effects of climate change on it | The biological diversity within soils and sediments may be orders of magnitude greater than that above the surface ..; .. activities of organisms dwelling within soils .. or the litter layer (here defined as below-surface biota) involve physiological or ecological interactions with organisms in above-surface habitats.; .. connections between functional groups across the soil and sediment surface can be highly specific and the presence of a particular functional group on one side of the surface can depend on that of another across the surface. |
| 622 | Addiscott, T.M. | Entropy and sustainability | 1995 | Soil (General); Sustainability | Journal | Eur. J. Soil Sci.; 46; 161-168 | English | Hardcopy:Partial | Modelling the soil as an open system based on non-equilibrium thermodynamics. | .. a closed [thermodynamic] system can exchange energy but not matter and open system can exchange both .. the soil is clearly and open system. .. Non-equilibrium thermodynamics describes an open system that tends towards a steady state characterised by minimum production of entropy.; .. perturbing a steady state causes an increase in entropy production but also that, when the perturbation is removed, the system returns towards the steady state with entropy production declining towards an eventual minimum.; The Principle of Minimum Energy provides a useful framework within which sustainability can be discussed. Natural ecosystems are sustainable not least because they become steady states characterised by minimum production of entropy.; .. we should seek agric'l systems that permit the establishment of steady states.Continuous arable agriculture, or even monoculture, may therefore be one of the more sustainable options available. |
| 1497 | Addiscott, T.M. | Tillage, mineralisation and leaching | 2000 | Mineralisation; Soil N Dynamics; Tillage | Journal | Soil Tillage Res.; 53 (3-4); 163-165 | English | Hardcopy:Full; Wordperfect:Full | Review (editorial of a special issue of the journal on tillage, mineralisation and leaching) | .. nitrate can be lost from the land even when no fertiliser is applied at all.; The microbes that are active in mineralising SOM .. particularly enjoy the conditions which they find when soil warm from the summer is re-wetted during early autumn, but this is just when the nitrate they produce is most untimely. .. This naturally produced nitrate is usually responsible for a larger proportion of the nitrate leached from the soil than fertiliser N applied to growing crops in spring ..; Roughly 70% of the N given to winter wheat crops .. is recovered in the harvested grain and straw. Stubble and roots remain in the soil, together with any material exuded from the roots, and together they contain about 15% of the fertiliser in organic form. .. this 15% means that H about 25-30 kg ha-1 of N from fertiliser is added to the soil's organic N each season. .. From 1977 onwards .. more N was given to the crop than it removed and by 1986 a total cumulative excess (of application over removal) of more than 300 kg ha-1 had built up during the 10 years. .. about 45% of this excess, about 145 hkg ha-1 of N, remained in the soil as organic N in 1986. This excess has more 0than doubled since then .. An extra 300 kg ha-1 of organic N in the soil is not necessarily a bad thing. The soil has become potentially more fertile, and roughly 3 Mg ha-1 of C has been sequestrated with the nitrogen. |
| 1498 | Addiscott, T.M., & Dexter, A.R. | Tillage and crop residue management effects on losses of chemicals from soils | 1994 | Soil N Dynamics; Tillage | Journal | Soil Tillage Res.; 30(2-4); 125-168 | English | Hardcopy:Partial | Review of causes of nutrient losses through leaching and run-off from agricultural systems and ways of abating them | . the decline in the practice of applying N fertiliser to autumn-sown crops in the autumn.Research had shown this to be unnecessary, wasteful and polluting .. cereal straw .. always immobilises mineral N when it is incorporated in the soil and some UK farmers are now expressing concern that, where straw has been incorp'd, their autumn-sown crops are now deficient of mineral N in the autumn. |
| 1499 | Agenbag, G.A. & Maree, P.C.J. | Effect of tillage on some soil properties, plant development and yield of spring wheat (Triticum aestivum L.) in stony soil | 1991 | Soil (General); Tillage | Journal | Soil Tillage Res.; 21(1-2); 97-112 | English | Hardcopy:Partial | Long-term field expt. to study the effect of zero tillage on wheat yields on shallow stony soils in south Africa. In four out of six year there was little difference in crops between different tillage treatments. | .. the lower maximum LAI [leaf area index] and yields obtained with no- and tine-tillage in 1981 and 1982 were the result of a combination of higher cone resistance, less mineral N in the soil at seeding and lower plant populations. |
| 623 | Agnelli, V., Trumbore, S.E., Corti, G. & Ugolini, F.C. | The dynamics of organic matter in rock fragments in soil investigated by 14C dating and measurements of 13C | 2002 | Greenhouse Gases; Soil Organic Carbon | Journal | Eur. J. Soil Sci.; 53; 147-159 | English | Hardcopy:Partial | In soils derived from sedimentary rocks the fraction coarser than 2 mm, which is called rock fragments, contains considerable amounts of organic C, comprising both humic and non-humic substances. The concentration of organic C in rock fragments is similar to that in fine earth. | The total amount of C in the upper metre of soil has been estimated to be about 1500 Pg. This is large relative to the C stored in biomass and the atmosphere.; Rock fragments .. contributed 4.5% to the total organic C content of the soil.; .. highly altered rock fragments host an active microbial populations.; The bulk OM in both fine earth and highly altered rock fragments in the A1 horizon contained significant amounts of recent C (bomb 14C) .. |
| 1500 | Ahl, C., Joergensen, R.G., Kandeler, E., Meyer, B. & Woehler, V. | Microbial biomass and activity in silt and sand loams after long-term shallow tillage in central Germany | 1998 | Soil Microorganisms; Tillage | Journal | Soil Tillage Res.; 49 (1/2); 93-104 | English | Hardcopy:Full; PDF:Full | Field expt. to compare the effects of ploughing and rotovation on soil microorganisms | The ploughless cultivation system used in our investigation, which is based on a horizontal axis rotary cultivator, led to a reduction in SOM, microbial biomass and microbial activity. This cultivation system changed also the community structure of soil microflora towards fungi. These effects are primarily due a compaction of the bottom parts in the former plough layer at 10-30 cm depth. |
| 624 | Aita, C., Recous, S. & Angers, D.A. | Short-term kinetics of residual wheat straw C and N under field conditions: characterisation by 13C15N tracing and soil particle size fractionation | 1997 | Soil Organic Carbon; Soil N Dynamics | Journal | Eur. J. Soil Sci.; 48 (2); 283-294 | English | Hardcopy:Full | 18-month field expt. to study the C & N fluxes that occur during the decomposition of straw, using stable isotope labelling. | Straw-derived C disappeared rapidly from the >2000 m fraction with an estimated half-life of 53 .. days .. [it] accumulated most rapidly and preferentially in the <50m fraction, which .. accounted for 70% of the residual `13C on day 574.; .. straw-derived C & N pass through the intermediate fractions (50-2000 m) very rapidly. |
| 792 | Al-Yahya, S.A. | Effect of storage conditions on germination in wheat | 2001 | Miscellaneous | Journal | J. Agron. Crop Sci.; 186; 273-279 | English | Hardcopy:Partial; PDF:Full | Expt. to measure the effect of moisture content, temperature and mechanical damage on wheat germination | The percentage germination decreased very slowly at a low moisture level (15%), low temperature (4$C) and low level of damage (0%), while it decreased rapidly at a high moisture level (24%), high temperature (40$C) and high level of damage (30%). |
| 488 | Albiach, R., Canet, R., Pomares, F. & Ingelmo, F. | Microbial biomass content and enzymatic activities after the application of organic amendments to a horticultural soil | 2000 | Compost & Biocontrol; Soil Organic Carbon | Journal | Bioresour. Technol.; 75; 43-48 | English | Hardcopy:Full; Wordperfect:Full | Exptal study of the effect of 5 organic amendments (MSW compost, sewage sludge, ovine FYM, vermicompost and a commercial humic acids solution) on the microbial biomass content and level of selected enzymatic activities. No statistically significant differences in soil microbial biomass between the treatments were found. The treatments gave significant enhancement of soil enzyme activity in the order MSW > ovine manure > sewage sludge > vermicompost/humic acid solution. | |
| 1096 | Alexandratos, N. | World food and agriculture: outlook for the medium and longer term | 1999 | Miscellaneous | Journal | Proc. Natl. Acad. Sci. U. S. A.; 96; 5908-5914 | English | Hardcopy:Partial; PDF:Full | Review of the global food productio situation | The fears of impending food crisis that dominated the thinking of some observers up to about mid-1997 have subsided .. It is now well accepted that, at least over the medium term, there appear to be no major global constraints to expanding world food production at a rate sufficient to match the growth of the effective demand for food.; As in the past, world agricultural production is likely to keep up with, and perhaps tend to exceed, the growth of the effective demand for food. |
| 27 | Alföldi, T., Spiess, E., Niggli, U. & Besson, J.M. | Energy input and output for winter wheat in biodynamic, bio-organic and conventional production systems | 1995 | Biodynamic Farming; Energy in Agriculture; Organic Farming | Book | Cook, H.F. & Lee, H.C.; Soil Management in Sustainable Agriculture; 574-578 | English | Hardcopy:Full | 6-year field expt. to compare the efficiency of conventional, organic and biodynamic farming systems. The conventional system had higher yield (by 10-15%) but lower efficiency than the organic systems, using 12%-25% more energy per kg of wheat produced, depending on the fertiliser rate (25 or 50 kg N per ha). The biodynamic system had a poorer energy balance than the organic one on account of the high energy consumption in the composting process. | |
| 123 | Alföldi, T., Wider, P., Niggli, U., Spiess, E., Dubois, D. & Besson, J.M. | Quality investigations in the long-term DOC-trial | 1996 | Biodynamic Farming; Miscellaneous; Organic Farming | Book | Raupp, J. (ed.); Quality of plant products grown with manure fertilisation, Proc. 4th mtg (concerted action AIR3-CT94-1940); | English | Hardcopy:Full; Wordperfect:Full | Expt. to compare the quality of conv'l, organic and biodynamic produce | Market quality (sizing) of biodynamically and organically grown potatoes was 25% lower compared to the conventional potatoes ..; The nitrogen content of biodynamically grown potatoes was 25% higher compared to the other treatments.; In the DOC-trial the nitrogen content of wheat was 10% lower in the two organic treatments than in the conventional wheat.; Neither the protein content nor the baking capacity of wheat was different among the farming systems. |
| 1709 | Allard, B. & Derenne, S. | Oxidation of humic acids from an agricultural soil and a lignite deposit: Analysis of lipophilic and hydrophilic products | 2007 | Uncategorised | Journal | Org. Geochem.; 38; 2036-2057 | English | PDF:Full | ||
| 1381 | Allison, F.E. & Klein, C.J. | Rates of immobilisation and release of nitrogen following additions of carbonaceous materials and nitrogen to soils | 1962 | Soil N Dynamics | Journal | Soil Sci.; 93; 383-386 | English | Hardcopy:Full | Lab. expt. to study the immobilisation of N in soils amended with straw and nitrate fertiliser. A maximum N immobilisation of 1.7% was reached after 20 @days, when 28% [?] of the straw C had been lost as CO2, and the C/N ratio of the residue was then 13.0. The corresponding figures for a soil amended with glucose (Winsor & Pollard, 1956) were 3.7%, 2 days, 40% and 6.2. | .. the quantity of N required by soil microorganisms in the decomposition of carbonaceous materials, such as straw, .. usually vary between 1.1 and 2.0% of the dry weight of readily decomposable plant materials, including the N originally present in the plant material ..; Immobilisation of N proceeded rapidly during the first 7 days, then at a constantly decreasing rate ..; N immobilisation during this initial 3 weeks paralleled closely the rate of H decomposition of the straw, as shown by CO2 evolution.; This difference between .. residual materials reflects .. the presence of lignin and other resistant constituents of the straw. |
| 1167 | Allison, S.D. & Vitousek, P.M. | Responses of extracellular enzymes to simple and complex nutrient inputs | 2005 | Soil Microorganisms | Journal | Soil Biol. Biochem.; 37 (5); 937-944 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to test the reaction of extracellular enzymes to the presence of nutrients in different (simple & complex) forms | Extracellular enzymes are the primary means by which soil microbes degrade complex organic cpds into small molecules that can be assimilated.; .. an enzyme's activity increased when its target nutrient was present in complex but not simple form and C & N were available.; .. microbes produce enzymes according to economic rules, but a substantial pool of mineral-stabilised or constitutive enzymes mediates this response. |
| 1166 | Allison, S.D., Hanson, C.A. & Treseder, K.K. | Nitrogen fertilisation reduces diversity and alters community structure of active fungi in boreal ecosystems | 2007 | Soil Microorganisms; Soil N Dynamics | Journal | Soil Biol. Biochem.; 39; 1878-1887 | English | Hardcopy:Partial; PDF:Full | Field expt. to test the effect of N deposition on the fungi of a boreal forest | ... N fertilisation reduces fungal taxonomic richness and alters community structure. These responses ... applied to both litter and soil environments. |
| 851 | Allmaras, R.R., Schomberg, H.H., Douglas, C.L. & Dao, T.H. | Soil organic carbon sequestration potential of adopting conservation tillage in U.S. croplands | 2000 | Greenhouse Gases; Tillage | Journal | J. Soil Water Conserv.; 55 (3); 365-373 | English | Hardcopy:Full | Modelling of C cycling in different cropping systems is used to show that changes in crop yields and in harvesting and tillage practices in the U.S. over @the last 30 years has resulted in a steady reduction in the quantity of CO2 released to the atmosphere from arable land and that some time in the last 15 years arable soils changed from being a net C source to a net C sink. | Soil .. C makes up about two thirds of the C pool in the terrestrial biosphere.; .. the estimated annual exchange is about 4% of the SOC pool or 811% of the atmospheric pool.; Components of the SOC pool in cropland have a wide range of susceptibility to decomposition .. half-lives from <1 to >1000 years.; The SOC pool in croplands converted from grasslands was reduced as much as 40% to reach a steady low state by about 1940.; SOC levels in tall-grass prairie soils decreased as much as 60%.; .. the mouldboard tillage system has SOC storage inferior to all other tillage systems ..; A combination of cover crop, double crop, no-tillage and infrequent use of non-mouldboard tillage has .. expanded the C sink.; [Because of] the shift from dominant mouldboard primary tillage in .. 1970 .. to a use on less than 8% of planted cropland in 1993, SOC storage has shifted from a C source to a C sink. |
| 1711 | Almendros, G., Guadalix, M.E., González-Vila, F.J. & Martin, F. | Preservation of aliphatic macromolecules in soil humins | 1996 | Uncategorised | Journal | Org. Geochem.; 24; 651-659 | English | PDF:Full | ||
| 717 | Alphei, J. & Scheu, S. | Effects of biocidal treatments on biological and nutritional properties of a mull-structured woodland soil | 1993 | Soil Microorganisms; Soil N Dynamics | Journal | Geoderma; 56(1-4); 435-448 | English | Hardcopy:Partial | Expt. to study microbial activity in a beechwood mull soil | Woodland mull soils are characterised by low nutrient availability to the soil microflora and the microflora is limited by nutrients or has a high demand on nutrients, particularly N and P.; In general the total soil respiration was increased by these [biocidal] treatments. In addition the NH4+-N content increased continuously ..; In contrast to the control soil no nitrification `occurred.; The flush in CO2 production following chloroform fumigation is known to be caused by decomposition of fumigated organisms in the soil. |
| 1501 | Alvarez, R., Díaz, R.A., Barbero, N., Santanatoglia, O.J. & Blotta, L. | Soil organic carbon, microbial biomass and CO2-C production from three tillage systems | 1995 | Soil Organic Carbon; Soil Microorganisms; Tillage | Journal | Soil Tillage Res.; 33; 17-28 | English | Hardcopy:Partial | Lab. expt. to test the effect of tillage on SOM distribution and mineralisation. Zero-tilled soils, compared with ploughed soils, were more stratified, had more coarse and labile OM and, in the top 5 cm., had twice the microbial biomass (0.43 mg C/g soil), three times the basal respiration (0.33 mg C/g soil) and 1.5 times the metabolic quotient (0.08 mg C/mg biomass C/day). | .. organic C was 42%-50% higher in the no-till soil than in the soil from the plough and chisel tillage systems.; A lower mineralisation intensity of SOM under no-till appeared to be the cause of the organic C accumulation. .. when crops are not buried, fungal growth predominates over bacterial growth .. As a result, the efficiency of the transformation of plant C into microbial C can rise, because fungi have a lower maintenance energy requirement than bacteria and this may lead to the formation of more humified OM. |
| 852 | Amado, T.J.C., Fernandez, S.B. & Mielniczuk, J. | Nitrogen availability as affected by ten years of cover crop and tillage systems in southern Brasil | 1998 | Cover Crops; Tillage | Journal | J. Soil Water Conserv.; 53 (3); 268-271 | English | Hardcopy:Full | In a comparison of conventional and zero tillage systems in Rio Grande do Sulzero tillage showed higher N availability. | After nine years no-tillage with the intensive cropping system resulted in a 24% increase in soil N as compared to conventional tillage; there was no difference in [maize] yield between tillage systems. |
| 1168 | Amato, M. & Ladd, J.N. | Decomposition of 14C-labelled glucose and legume material in soils: properties influencing the accumulation of organic residue C and microbial biomass C | 1992 | Soil Microorganisms | Journal | Soil Biol. Biochem.; 24 (5); 455-464 | English | Hardcopy:Partial | Lab. expt. using 14C labelling to study the decomposition of added glucose and legume materials in 23 soils after 44 and 66 weeks incubation. A close correlation was found between the size of both native and labelled biomass and the properties of the soil, e.g. clay content, CEC, pH, fine pores as a proportion of total pore space, etc. The attaining of maximum biomass took only a few days with glucose but sever months with plant materials and even then the residue could contain some undecomposed .. plant constituents. | .. soil charge, and perhaps soil structure, are the important factors of influence on biomass 14C accumulation. Clearly microorganisms in soils are adsorbed to surfaces within pores.; .. interactions between adsorption of organisms to soil surfaces and pore size distributions are important factors in determining the survival of the soil microflora.; These factors may override such influences as substrate type, concentration and efficiency of utilisation in determining biomass C concentration in soils .. |
| 625 | Ambus, P. | Nitrous oxide production by denitrification and nitrification in temperate forest, grassland and agricultural soils | 1998 | Greenhouse Gases; Soil N Dynamics | Journal | Eur. J. Soil Sci.; 49; 495-502 | English | Hardcopy:Partial | Expt. to study the rate of N2O production from various soils | x; N2O is produced by two mainly biological pathways, namely denitrification and @chemoautotrophic nitrification .. In denitrification N2O is produced as an intermediate compound in a sequence of enzymatic reactions whereby NO3- is reduced to N2. .. In autotrophic nitrification N2O is produced as a result of denitrification by nitrifiers which reduce NO2- under small pressures of O2. .. `Since nitrification activity ceases as O2 is depleted, rapid N2O production is (more likely to be associated with denitrification.; The total N2O production was strongly influenced by landscape position and was especially large in low-lying position with wet organic soils. .. By contrast forest soils produce little N2O .. irrespective of landscape position. |
| 718 | Amelung, W. & Zech, W. | Minimisation of organic matter disruption during particle-size fractionation of grassland epipedons | 1999 | Soil Organic Carbon | Journal | Geoderma; 92; 73-85 | English | Hardcopy:Partial | A study of the methodology of particle-size fractionation using ultrasonic dispersion with a view to avoiding artefacts. The degree of dispersion depended on the energy applied, the climatic origin of the soil samples and the type of sonifier. | |
| 1395 | Amelung, W., Flach, K.W. & Zech, W. | Neutral and acidic sugars in particle-size fractions as influenced by climate | 1999 | Soil Organic Carbon; Soil Microorganisms | Journal | Soil Sci. Soc. Am. J.; 63; 865-873 | English | Hardcopy:Partial | Expt. to compare the saccharide concentrations in soils taken from different latitudes in North America - from Canada to Texas | Plant-derived sugars, especially pentoses, are a source of energy and C for soil fauna and microorganisms. .. the microorganisms re-synthesise primarily hexoses and release them to the soil.; .. saccharides .. tend to accumulate in older SOM with increasing soil depth, relative to even the chemically more stable lignin. .. plant-derived [neutral] sugars were concentrated in sand-size POM, whereas microbe-derived carbohydrates [amino-sugars] accumulated in the clay ..; The growth of microorganisms is more or less proportional to the root input, as will be the production of microbially derived saccharides. |
| 1396 | Amelung, W., Flach, K.W. & Zech, W. | Lignin in particle-size fractions of native grassland soils as influenced by climate | 1999 | Lignin and CBW; Soil Organic Carbon | Journal | Soil Sci. Soc. Am. J.; 63; 1222-1228 | English | Hardcopy:Partial | Expt. to study the effect of climate on lignin degradation | Lignin is one of the predominant components in grass and root litter. Once the more labile components have been degraded, slowly decomposing lignin dominates the shape of litter decomposition curves.; Particle-size fractionation into clay, silt, fine sand and coarse sand yielded four significantly different lignin pools. The degree of lignin alteration proceeded as particle-size diameter decreased. |
| 1397 | Amelung, W., Zech, W., Zhang, X., Follett, R.F., Tiessen, H., Knox, E. & Flach, K.W. | Carbon, nitrogen and sulfur pools in particle-size fractions as influenced by climate | 1998 | Soil Organic Carbon; Soil N Dynamics | Journal | Soil Sci. Soc. Am. J.; 62 (1); 172-181 | English | Hardcopy:Partial | Expt. to study the C, N and S pools in samples taken from the top 10 cm. of native grassland soils from sites ranging from Canada to Texas | The clay fraction contained about 43% of the total SOC, 56% of the total N and 62% of the total S.; .. apart from foliar lignin, MAT [mean annual temp.] and clay content are the key site-specific parameters influencing SOM dynamics. |
| 541 | Anderson, J.M. | The effects of climate change on decomposition processes in grassland and coniferous forests | 1991 | Soil Organic Carbon | Journal | Ecol. Appl.; 1 (3); 326-347 | English | Hardcopy:Full; PDF:Full | Review of the possible effects of higher atmospheric CO2 concentrations and higher temperatures on the decomposition of plant residues in temperate and boreal regions | .. while mean NPP increases by a factor of ca.20 from tundra to tropical rain forest, MRTs of dead OM decrease by a factor of ca.200, primarily because soil temperatures limit decomposition more than air temperatures limit production.; .. C enrichment without increased nutrient supply resulting in higher C/N or lignin/N ratios and increased polyphenol concentrations in litter. If this low resource quality material decomposes slower than the current litter, negative feedback effects on plant production through reduced nutrient availability and increased C storage in litter pools may result.; White spruce exhibits an H enormous range of aboveground biomass (0.92-23.3 kg/m2) and production (89-2853 g m-2 yr-1) ..; .. a 4$C change in the boreal zone would probably result in a C flux that was increased by <6 Pg/yr. |
| 25 | Anderson, R.V., Coleman, D.C. & Cole, C.V. | Effects of saprotrophic grazing on net mineralisation | 1981 | Mineralisation; Soil N Dynamics; Soil (General) | Book | Clark, F.E. & Rosswall, T. (eds.); Terrestrial Nitrogen Cycles: Processes, Ecosystem Strategies and Management Impacts; 201-216 | English | Hardcopy:Partial | Review of the role of soil fauna - protozoa, nematodes, annelids, arthropods (including collembolans, mites, ants, termites and insects) - in litter processing and nutrient mineralisation. A table is given of production efficiency and the excretory products of the various groups of fauna. | As much as 86% of the autotrophic production and 95% of the heterotrophic production and respiration occur in the belowground component of most ecosystems.; The role of fauna in energetics and mineralisation of C is usually very small .. compared with microfloral activity. However .. their effect on system activity can be significant.; .. earthworm metabolism accounting for less than 10% of the litter energy content .. 6% of the bound N ingested by worms was excreted in a form available to plants. Earthworms process litter, decreasing its C/N ratio ..; Besides increasing litter processing microfauna and mesofauna increase nutrient concentrations in the processed material, because respiratory loss of C results in low C/N ratios.; .. soil fauna .. excrete N, usually as ammonium, urea or amino acids. Because C/N ratios of fauna are higher than .. those of the microflora consumed, N is mineralised. |
| 1170 | Anderson, T.H. & Domsch, K.H. | Application of eco-physical quotients (qCO2 and qD) on microbial biomasses from soils of different cropping histories | 1990 | Soil Microorganisms | Journal | Soil Biol. Biochem.; 22 (2); 251-255 | English | Hardcopy:Partial | Study of microbial metabolic quotient and death quotient on soils under longxterm monoculture and rotation treatments. The metabolic quotient (qCO2) is the @ratio of the basal respiration to the biomass size and is a measure of the CO2 produced per unit biomass and unit time. The death quotient is the biomass C loss per unit biomass and unit time. The average qCO2 (& qD) in this study were 1.1 & 0.65 (3.01 & 1.88) for the monoculture and rotation soils respectively. | .. rate constants of the total biomass under in situ conditions are always lower .. than comparable values derived from .. optimal in vitro conditions.; .. microbial communities may differ with respect to energetic efficiency. The observation that microbial biomasses from plots under long-term M [monoculture] produce .. almost twice as much CO2 per unit cell mass and time and show a death rate which is ca. twice as high as compared to microbial biomasses from continuous CR [rotation] would speak for a higher energy demand in the first group. |
| 1171 | Anderson, T.H. & Domsch, K.H. | The metabolic quotient for CO2 (qCO2) as a specific activity parameter to assess the effects of environmental conditions, such as pH, on microbial biomasses of forest soils | 1993 | Soil Microorganisms | Journal | Soil Biol. Biochem.; 25 (3); 393-395 | English | Hardcopy:Full | Field expt. to study the dependence of the metabolic quotient qCO2 on soil pH. @In acid forest soils (pH around 3) qCO2 was about 2.2 mg CO2-C/g SMB-C/hour, whereas in neutral forest soils the value was about double that. Microbial biomass C as a proportion of total SOC averaged 0.56 in acid forest soils and 2.2 in neutral ones, which compares with 2.6 in agricultural soils. | |
| 1712 | Anderson, T.H. & Joergensen, R.G. | Relationship between SIR and FE estimates of microbial biomass C in deciduous forest soils at different pH | 1997 | Uncategorised | Journal | Soil Biol. Biochem.; 29; 1033-1042 | English | PDF:Full | ||
| 1169 | Anderson, T.H., Domsch, K.H. | Ratios of microbial biomass carbon to total organic carbon in arable soils | 1989 | Green Manure; Soil Organic Carbon; Soil Microorganisms | Journal | Soil Biol. Biochem.; 21 (4); 471-479 | English | Hardcopy:Partial | Measurement of Cmic/Corg ratios in soils from long-term agricultural expt.s.The mean biomass C/total organic C ratio was 2.3% and 2.9% under monoculture and rotation respectively, when the soil was amended with chemical fertiliser, around 5% with straw or FYM and up to 4% with green manure ( straw). This latter figure was seen as a transient increase due to the available C in the green manure. The Cmic/Corg relationship is only linear up to an organic C content of 2.5%. Above that it falls off steeply. | `; A wide spectrum of Cmic/Corg ratios ranging from 0.27% to over 7% are reported in the literature. .. the few data .. available from long-term field expt.s correspond well with the [figures] in the present investigation.; .. clay content had only little influence on the Cmic/Corg ratio.; After a change, e.g. in agricultural management, .. soil takes from 20-50 years to move to the new equilibrium state .. the soil microbial biomass responds more quickly to the change than does the amount of OM in the soil .. |
| 331 | Andrade, G., Azcón, R., Bethlenfalvay, G.J. | A rhizobacterium modifies plant and soil responses to the mycorrhizal fungus Glomus mosseae | 1995 | Soil Microorganisms | Journal | Appl. Soil Ecol.; 2; 195-202 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to demonstrate that rhizobacteria & mycorrhizal fungi, acting separ- ately or in concert, may have both positive & negative effects on plants and on soil aggregation | The rhizobacterium had no significant effect on plant biomass production in either soil in the absence of the VAM fungus, but decreased plant growth by more than 30% in its presence. It enhanced the root/shoot and seed/plant ratios in plants of both VAM and non-VAM treatments. Without the VAM fungus, both soils disaggregated. This .. was significantly less severe when the rhizobacterium was present. With the VAM fungus, aggregation increased up to 27% during the expt, but the rhizobacterium did not affect this process significantly. |
| 1714 | Andrews, J.A., Harrison, K.G., Matamala, R. & Schlesinger W.H. | Separation of Root Respiration from Total Soil Respiration Using Carbon-13 Labeling during Free-Air Carbon Dioxide Enrichment (FACE) | 1999 | Uncategorised | Journal | Soil Sci. Soc. Am. J.; 63; 1429-1435 | English | PDF:Full | ||
| 1701 | André, M., Bréchignac, F. & Thibault, P. | Biodiversity in model ecosystems | 1994 | Uncategorised | Journal | Nature (Lond.); 371; 565 | English | PDF:Full | ||
| 332 | Andrén, O., Brussaard, L. & Clarholm, M. | Soil organism influence on ecosystem-level processes - bypassing the ecological hierarchy? | 1999 | Miscellaneous | Journal | Appl. Soil Ecol.; 11; 177-188 | English | Hardcopy:Partial; PDF:Full | Review of soil ecology, arguing that soil ecosystems models only need to be consistent with data at two levels: the ecosystem and the organism levels | |
| 1713 | Andrén, O., Kirchmann, H., Kätterer, T., Magid, J., Paul, E.A. & Coleman, D.C. | Visions of a more precise soil biology | 2008 | Uncategorised | Journal | Eur. J. Soil Sci.; 59; 380-390 | English | PDF:Full | ||
| 1502 | Angers, D.A. | Water-stable aggregation of Québec silty clay soils: some factors controlling its dynamics | 1998 | Soil Organic Carbon; Tillage | Journal | Soil Tillage Res.; 47 (1/2); 91-96 | English | Hardcopy:Partial; PDF:Full | Review of exptal. evidence for the mechanism of sequestration of C following changes to the soil management | .. the clay and silt particles of these soils are relatively saturated in OM which leads to highly stable microaggregation. Any additional OM accumulation in the surface soil provided by reduced- or no-till conditions, perennial forage crops or FYM additions would lead to increased macroaggregation and be related to the accumulation of particulate OM. This hypothesis helps to explain the relatively high responsiveness of soil structure, and in particular stable macroaggregation, to changes in cropping systems .. |
| 421 | Angers, D.A. & Caron, J. | Plant-induced changes in soil structure: processes and feedbacks | 1998 | Roots & Rhizodeposition; Soil (General) | Journal | Biogeochemistry (Dordr.); 42; 55-72 | English | Hardcopy:Full; PDF:Full | Review of the role of plants in affecting soil structure | ... roots form macropores which favour fluid transport. They also create zones of failure which help to fragment the soil and form aggregates. This phenomenon is enhanced by the wetting and drying cycles associated with plant growth. Drying also causes shrinkage and strengthening of the soil. Anchorage of roots and the exudation of cementing material stabilises soil structure. Finally, as a source of C, roots and plant residues provide a food source to the microflora and fauna which contribute to structure formation and stabilisation. |
| 1398 | Angers, D.A. & Giroux, M. | Recently deposited organic matter in soil water-stable aggregates | 1996 | Soil Organic Carbon | Journal | Soil Sci. Soc. Am. J.; 60 (5); 1547-1551 | English | Hardcopy:Full | Expt. to trace the fate of fresh OM in the soil. Recent crop residues comprised 9% of total SOC, 1% of the SOC in microaggregates and 20% of the SOC in waterstable aggregates >1 mm. The water stability of macroaggregates decreased according to cropping in the order hay meadow > wheat/ barley > maize. The half-life of recent maize-derived C in water-stable macroaggregates was 13 years. | .. slaking-resistant macroaggregates are enriched in, and probably stabilised by recently deposited OM.; macroaggregates are stabilised by [more labile] OM such as fungal hyphae, labile carbohydrates and aliphatic compounds that are .. younger than the bulk of the SOM .. while microaggregates would be stabilised by more processed SOM. |
| 1021 | Angers, D.A. & Recous, S. | Decomposition of wheat straw and rye residues as affected by particle size | 1997 | Soil Organic Carbon | Journal | Plant Soil; 189; 197-203 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the decomposition of mature wheat straw and green rye plants cut up into pieces of different sizes, 0.03-10 cm long. Initially finer particles decompose faster than coarser, but after a certain period (which is shorter, the higher the N content of the residue) the finer particles begin to decompose slower than the coarser. | We hypothesise that in this study two dominant opposite effects resulted from increasing residue contact with soil: 1) acceleration of decomposition due to increasing nutrient and water exchange with soil and 2) increase of C stabilisation by soil physical protection. In the case of wheat the response to size could have been a combination of these two effects while in the case of rye the first effect was only transitory.; .. a more even distribution of decomposition sites in the soil .. would allow for better access to nutrients and water.; .. more intimate contact with soil resulted in lower turnover rates owing to protection of microbial biomass and newly-formed organic substances. |
| 1503 | Angers, D.A., Bolinder, M.A., Carter, M.R., Gregorich, E.G., Drury, C.P., Liang, B.C., Voroney, R.P., Simard, R.R., Donald, R.G., Beyaert, R.P. & Martel, I. | Impact of tillage practices on organic carbon and nitrogen storage in cool humid soils of eastern Canada | 1997 | Soil Organic Carbon; Tillage | Journal | Soil Tillage Res.; 41 (3-4); 191-201 | English | Hardcopy:Partial; PDF:Full | Field expt. to compare C storage in 8 soils under zero tillage, chisel and mouldboard ploughing. Generally the soils under zero tillage only stored more OM than ploughed soils only in the top 10 cm. | .. under Easter Canadian conditions, where crop production and residue inputs are not affected by tillage, reduced tillage systems would not result in the storage of more SOM in the entire soil profile at least in a 5-10 year period. |
| 28 | Angers, D.A., Lafrance, P., Simard, R.R., Pelletier, F. & Légère, A. | Temporal variation in soil microbial biomass and activity as influenced by compost and atrazine applications | 1995 | Soil Microorganisms | Book | Cook, H.F. & Lee, H.C.; Soil Management in Sustainable Agriculture; 538-543 | English | Hardcopy:Full | 2-year field expt. to measure the effect of compost and herbicides on the quantity and activity of soil microbial biomass. SMB-C and activity were increased by compost application but unaffected by atrazine herbicide. | In a dry season temporal variations in microbial biomass carbon were related to variations in soil water content. |
| 626 | Angers, D.A., Recous, S. & Aita, C. | Fate of carbon and nitrogen in water-stable aggregates during decomposition of 13C15N-labelled wheat straw in situ | 1997 | Soil Organic Carbon; Soil N Dynamics | Journal | Eur. J. Soil Sci.; 48 (2); 295-300 | English | Hardcopy:Partial | 18-month field expt. to study the incorporation of C & N from wheat straw into soil aggregates. During the first 200 days the straw C content in the macroaggregates (>250 m) rapidly increased but subsequently decreased. The proportion of straw C in the fractions <250 m increased throughout the expt. At the end of the expt. about 90% of the residual C from the straw had been incorporated into the soil fractions - about half of it in the 50-250 m fraction. | `; .. the distribution of 15N in the fractions with time was generally similar to (13C except that more 15N than 13C was recovered in the <50 m fraction at the expense of the larger fractions.; .. the C/N ratio decreased with decreasing aggregate size.; .. after 50 days 40% of the added C had mineralised. |
| 877 | Anon | Noch viele Frage offen | 2002 | Clover Sward; Stockless Farming; Tillage | Journal | Landwirtschaft ohne Pflug; 6; 15-17 | German | Hardcopy:Full | A field-scale expt. in direct sowing wheat into a legume sward. White clover is best, but grows so aggressively in the summer that, if the wheat is sown in July/early August (Fukuoka method), the clover out-competes it, so sowing in late August and early September is best. Any later gives poor results. White clover appears to have an allelopathic effect on competing species in summer. Grazing the wheat/clover in late autumn with sheep controls the white clover and stimulates tillering of the wheat. Rather than zero tillage the intention seems to be to plough twice in a 5-year rotation. | Ausgangspunkt fGr den Beginn der Versuche mit Biodirektsaat war die Feststellung, da sich nach 8 Jahren Getreide- und K?rnerleguminosenanbau die Getreideertrge auf den sandigen Boeden bei etwa 20 dt/ha einpegelten und damit der ?kologische Landbau nicht mehr wirtschaftlich war.; Die vom .. Fukuoka empfohlene Methode, Weizen bereits im Juli breitwGrfig im Weiklee zu verteilen, funktioniert deshalb hier offenbar nicht! |
| 1589 | Anon | Farming and fossil fuels | 1975 | Sustainability | Journal | Span; 18 (1); | English | Hardcopy:Partial | Farming is too dependent on fossil fuels. | .. only sunlight, wind, water power (including tides) and geothermal energy can be regarded as inexhaustible.; .. agriculture's prime role up to now has always been to fix massive amounts of energy from the sun ..; .. the development of communities beyond the stage of peasantry has always depended on farmers being able to reap a great deal more than they eat.; .. advanced agriculture is using up several times more energy than is contained in the crops and animals ..; .. the world's agriculture [is] arguably very wasteful in the way some of its primary products (e.g. grains) are used for the production of secondary products such as meat.; It will certainly be essential, for the foreseeable future, to continue to use considerable amounts of fossil fuel in support of world agriculture, even though that amounts to spending capital to balance the current account.; .. [there must be] determined efforts to find ways and means of using less energy in farming .. and using it much more efficiently. |
| 1639 | Anon | Easing farmers' Burden in Nepal | 2003 | Tillage | Website | www.rwc-prism.cgiar.org/rwc/Nepal-story.asp | English | Hardcopy:Full | A brief review of the beneficial effects of zero tillage and small-scale mechanisation on the farmers of southern Nepal. Wheat yields are being raised from an average of 1.6 tons per ha. to around 4 tons per ha. Spread of the news about the advantages of zero tillage by word-of-mouth ensures rapid adoption of the method. | The simplest reduced tillage technique is surface seeding. .. farmers simply toss wheat seed onto moist soil immediately before or after rice harvest. .. even the poorest farmers can practice [it].; To discourage birds from feasting on unprotected seed [they use] a slurry of FYM, in which the seed is soaked before it is placed on the soil.; .. the [Rice-Wheat] Consortium differs from many research partnerships. It does not see itself as simply giving promising options to farmers; instead, it is a partnership in which farmers are welcome to expt., assume ownership and share observations. |
| 1640 | Anon | Partitioning soil respiration | Roots & Rhizodeposition | Website | English | Wordperfect:Full | Review of methods of quantifying the partitioning of belowground respiration between roots & soil, including trad. methods like component integration and root exclusion (by trenching or gap formation) and modern methods using C-13 natural abundance | Trenches were dug 0.5 m outside of the plots to a depth of 70-100 cm (20 cm below the rooting depth) and the roots were excluded with ... fibre-glass sheets... Root contribution to total soil respiration was ... 33% or 123 g C/sq m/yr.; ... expts using 30 m gaps ... to compare vegetation-free soil with nearby vegetated soil ... Respiration rates of roots ranged from 40% to 51% ..; Smaller gap sizes were used ... by Ohashi ... Root respiration accounted for 57% of total soil respiration ...; Rochette ... quantified rhizosphere-respired CO2 from maize (C4) grown on soil previously cropped with wheat (C3) ... rhizosphere respiration contributed up to 43% of total soil respiration ... | ||
| 371 | Antai, S.P. & Crawford, D.L. | Degradation of softwood, hardwood and grass lignocelluloses by two Streptomyces strains | 1981 | Lignin and CBW; Soil Organic Carbon | Journal | Appl. Environ. Microbiol.; 42 (2); 378-380 | English | Hardcopy:Full; PDF:Full | Study of lignocellulose decomposition by bacteria on different substrates. After 12 weeks lignin loss from wood was about 30% and from grass about 42%. The total weight losses of lignocellulose were about 20% and 53% respectively. | .. both Streptomyces strains substantially degraded both the lignin and carbohydrate components of each lignocellulose ..; Lignin degradation by these bacteria includes the oxidation of both aromatic rings and propane side chain `lignin carbons to CO2. Streptomyces trains have been shown to destroy the integrity of both lignified and non-lignified plant cell walls within intact woody plant tissues. |
| 1478 | Aoyama, M. & Nozawa, T. | Microbial biomass Nitrogen and mineralisation-immobilisation processes of Nitrogen in soils incubated with various orgganic materials | 1993 | Green Manure; Mineralisation; Soil N Dynamics | Journal | Soil Sci. Plant Nutr.; 39 (1); 23-32 | English | Hardcopy:Partial | 16-week lab. study of N dynamics in soils amended with chicken manure, clover leaves, FYM, bark compost and rice straw. The maximum increase in biomass N was 4%, 13.6%, 13.5%, 5.8% and 13.4% respectively. The low figure for the bark compost was suppose to be due to the labile portion of the bark having been used up in the composting process, leaving mainly recalcitrant OM. Chicken manure was rapidly mineralised from the start. Clover leaves showed a 2-week lag before mineralis'n started, during which microbial biomass N increased but subsequently rapidly decreased. With FYM and rice straw immobilisation started at once and continued for 4 and 16 weeks respectively. The biomass N increased to a maximum in the first 2 weeks and remained high throughout the immobilisation period. | Hirose (1973) divided .. plant residues into 3 groups: (1) rapid N mineralis'n .. from the beginning of incubation (C/N ration 5.6-11.3); (2) N mineralis'n started just after limited N immobilisation (C/N ration 15.3-20.6); (3) N immobilisation occurred from the beginning of incubation and continued for a long .. time (C/N ration 37.1-64.4). |
| 719 | Arocena, J.M. & Opio, C. | Prescribed fire-induced changes in properties of sub-boreal forest soils | 2003 | Miscellaneous | Journal | Geoderma; 113; 1-16 | English | PDF:Full | Field expt. to study the effect of forest fire on the soil | We observed higher soil pH, exchangeable Ca, Mg, K and Na and base saturation in burnt plots compared to unburnt plots.; Fires dramatically alter nutrient cycling through volatilisation, substrate transfer, in the form of particulate matter, smoke and ash, as well by inducing nutrient losses and leaching. ... Fires influence long-term nutrient supply through loss of OM and cations bound to burned forest floor.; ... the reduction in CEC and the generation of thermal cracks in feldspars and other soil aggregates could accelerate weathering due to increased surface area and result in loss of K, Ca & Mg through leaching. |
| 203 | Arshad, M.A. & Martin, S. | Identifying critical limits for soil quality indicators in agro-ecosystems | 2002 | Soil (General) | Journal | Agric. Ecosyst. Environ.; 88; 153-160 | English | Hardcopy:Partial | A qualitative discussion of the question of soil quality indicators. Guidelines for monitoring soil quality are proposed, involving eight steps, of which steps 4 to 7 are: select a set of indicators, select a reference point (baseline value) for each indicator, specify the critical limits for each of the selected indicators, transform the indicators into a soil quality/sustainability index. | .. selection of soil indicators will vary with societal goals .. the following seem to be suitable indicators for crop production in most cases: OM, topsoil depth, infiltration, aggregation, pH, electrical conductivity, suspected soil pollutants and soil respiration. Crop yield can be used as an integrator of the foregoing soil indicators. |
| 1504 | Arvidsson, J. & Hankansson, I. | A model for estimating crop yield losses caused by soil compaction | 1991 | Soil (General) | Journal | Soil Tillage Res.; 20 (2-4); 319-332 | English | Hardcopy:Partial | Modelling the effects on crop yields of soil compaction caused by traffic, recompaction after ploughing, persistence of plough-layer compaction after ploughing and subsoil compaction. | |
| 1172 | Ashman, M.R., Hallett, P.D. & Brookes, P.C. | Are the links between soil aggregate size class, soil organic matter and respiration rate artefacts of the fractionation procedure? | 2003 | Soil Organic Carbon | Journal | Soil Biol. Biochem.; 35 (3); 435-444 | English | Hardcopy:Full; PDF:Full | Expt. to study how variations in aggregate fractionation procedures influence the chemical and biological properties of different sized soil aggregates | .. the chemical and biological properties of aggregates depend on the fractionation procedure. .. the observed relationships between aggregate size and other properties, for example biological activity, must be interpreted in terms of the disruptive mechanisms used to fractionate aggregated soil. .. the aggregate hypothesis has serious weaknesses, the aggregates measured being largely an artefact of the chosen method of separation. .. future work should also consider biological activities at soil pore surfaces. It is at the surface of these channels that parameters such as oxygen supply, plant roots, root exudates and fresh OM inputs first interact with the soil. Biological processes in this region are therefore likely to be more important than those occurring in the bulk soil. |
| 831 | Askegaard, M. & Eriksen, J. | Growth of legume and non-legume catch [cover] crops and residual-N effects in spring barley on coarse sand | 2007 | Cover Crops; Green Manure; Soil N Dynamics | Journal | J. Plant Nutr. Soil Sci.; 170 (6); 773-780 | English | Hardcopy:Partial | Field expt. to measure the growth and residual N of various cover crops | .. the legume cover crops had a significantly larger aboveground dry-matter production and N content in the autumn than the non-legumes. The autumn N uptake of the non-legumes was 10-13 kg N ha-1 in shoots and approx. 9 kg ha-1 in the roots. The shoot N content of white clover .. was 55-67 kg ha-1 and the root N content .. was approx. 25 kg ha-1. [Its] N fertilizer-replacement values in a `following unfertilised spring barley [was] 120 .. kg N ha-1 .. |
| 1479 | Askegaard, M., Olesen, J.E. & Kristensen, K. | Nitrate leaching from organic arable crop rotations: effects of location, manure and catch crop | 2005 | Cover Crops; Soil N Dynamics | Journal | Soil Use Manag.; 21 (2); 181-188 | English | Hardcopy:Partial; PDF:Full | Field expt. to test the effects of legumes and cover crops on nitrate leaching | Leaching losses from the crop rotation with grass-clover green manure & without @catch crops were 104, 54 & 35 kg N ha-1 yr-1 on the coarse sand, the loamy sand and the sandy loam respectively. There was no effect of manure application or time of ploughing-in the grass-clover green manure crop on the accumulated nitrate leaching from the entire rotation.; The inclusion of catch crops in the rotation with grass-clover green manure decreased nitrate leaching by 38% for the coarse sand .., 30% for the loamy sand .. and 26% for the sandy loam .. |
| 1715 | Asman, W.A.H., Sutton, M.A. & Schjørring, J.K. | Ammonia: emission, atmospheric transport irnd deposition | 1998 | Uncategorised | Journal | New Phytol.; 139; 27-48 | English | PDF:Full | ||
| 969 | Augris, N., Balesdent, J., Mariotti, A., Derenne, S. & Largeau, C. | Structure and origin of insoluble and non-hydrolyzable aliphatic organic matter in a forest soil | 1998 | Lignin and CBW; Soil Organic Carbon | Journal | Org. Geochem.; 28 (1/2); 119-124 | English | Hardcopy:Full; Wordperfect:Full | Field expt. to study the very recalcitrant aliphatic material in a loamy forest soil, which are shown to be related to cutans and suberans from plants and comprise 5% of the total SOC and 25% of the total humin in this soil. | A new family of insoluble non-hydrolysable highly aliphatic bio-macromolecules was discovered recently in .. the cuticle and periderm of a number of higher plants and named cutans and suberans respectively .. These bio-macromolecules are characterised by an unusually high resistance to drastic base and acid hydrolyses .. based on a network of long saturated hydrocarbon chains. .. the structure .. is quite different from that of lignins, previously considered as by far the most resistant constituents in higher plants. |
| 1173 | Aulakh, M.S., Doran, J.W., Walters, D.T. & Power, J.F. | Legume residue and soil water effects on denitrification in soils of different texture | 1991 | Soil N Dynamics | Journal | Soil Biol. Biochem.; 23 (12); 1161-1167 | English | Hardcopy:Full | Lab. expt. to study the effect of water content and amendment with legume residues on the rate of denitrification in soil | Total N losses via denitrification .. were lowest .. at 60% WFPS and greatest at 90% WFPS.; .. incorporated low C/N-ratio plant residues .. apparently increases denitrification through increased microbial activity.; Total N losses from residue amended soils at 60% WFPS were 1-2 orders of magnitude higher than those from soils without residue. |
| 1399 | Aulakh, M.S., Doran, J.W., Walters, D.T., Mosier, A.R. & Francis, D.D. | Crop residue type and placement effects on denitrification and mineralisation | 1991 | Mineralisation; Soil N Dynamics | Journal | Soil Sci. Soc. Am. J.; 55; 1020-1025 | English | Hardcopy:Full | Lab. expt. to study the N mineralisation and losses from soil treated with surface-applied or incorporated plant residues | x; Denitrification was greatest during the first 8 d, as was CO2 evolution. Initial denitrification with surface-placed residues was less than with incorporated residues, but cumulative losses over 35 d did not differ significantly.; Substantial N immobilisation occurred with .. incorporated or surface-placed .. residue with wide C/N ratios .., whereas, with low C/N-ratio vetch, significant mineralisation occurred. After 35 d, 51% & 36% of N in incorporated & surface-placed vetch residue respectively was mineralised. |
| 445 | Aulakh, M.S., Khera, T.S., Doran, J.W. & Bronson, K.F. [5 pp. only] | Denitrification, N2O and CO2 fluxes in rice-wheat cropping systems as affected by crop residues, fertiliser N and legume green manure | 2001 | Greenhouse Gases; Green Manure; Soil N Dynamics | Journal | Biol. Fertil. Soils; 34; 375-389 | English | Hardcopy:Partial | Four-year field study of an irrigated rice-wheat rotation are presented. The effects of including the green manure sesbania in the rotation and of incorporating crop residues were observed. | The atmospheric concentration of N2O is increasing at a current rate of about 0.25% per year. N2O is emitted from agricultural soils by both denitrification and nitrification processes. The total amount of N2O emitted globally from N`fertilised soils is estimated to be 1.5 Tg N2O-N per year, which represents about (10% of the total N2O-N emission to the atmosphere.; .. up to 50% of the fertiliser N applied to wetland rice remains unaccounted for in 15N-balance studies .. substantial amounts of applied fertiliser N and green manure N (2333%) are lost via nitrification and denitrification during rice cropping.; .. the inclusion of sesbania .. green manure in an irrigated rice-wheat cropping system on porous soils results in a greater crop productivity and reduces nitrate leaching to lower soil depths as compared with chemical fertilisers. |
| 1103 | Avery, A.A., Prakash, C.S., McHughen, A., Trewavas, A.R. & Gregori, T.R. de | What kind of farming works best? | 2005 | Organic Farming | Journal | Science; 307; 1410-1411 | English | Hardcopy:Full | Letter criticising Pimentel's review of the book Mendel in the Kitchen: a Scientist's View of Genetically Modified Foods, by Fedoroff and Brown, and Pimentel's response | The Soil and Water Conservation Society says that herbicide-based low- and no-tillage cropping systems are the most sustainable ever ..; .. many long-term studies have shown a 10 to 40% org. yield deficit.; .. organic approaches would reduce the use of fossil energy in corn production by about 30 percent, due to not using synthetic fertiliser, but .. only by using far more land per ton of food produced. Replacing synthetic nitrogen fertiliser would require at least a fourfold increase in manure applications or equivalent green manure crops.; Worldwide, crops are cultivated on 11% of the world's land area .. the World Health Organisation recently reported that 3.7 billion people are malnourished. |
| 204 | Baggs, E.M., Rees, R.M., Castle, K., Scott, A., Smith, K.A. & Vinten, A.J.A. | Nitrous oxide release from soils receiving N-rich crop residues and paper mill sludge in eastern Scotland | 2002 | Greenhouse Gases; Soil N Dynamics | Journal | Agric. Ecosyst. Environ.; 90; 109-123 | English | Hardcopy:Partial | The incorporation of crop residues (especially those with a low C/N ratio like legumes or horticultural crops rather than high C/N residues like cereal straw) @can result in increased N2O emission from the soil. For example, incorporation of lettuce residues can temporarily increase N2O emission by up to 1.1 kg N2O-N per ha. during the first two weeks. In the expt.s reported here fields containing vegetable residues (from previous lettuce and calabrese crops) were treated with paper mill sludge and then cultivated by one of three methods - rotary tillage, ploughing (to 15 cm. depth) and deep ploughing (to 35 cm. depth). The N2O emission was monitored to see if the paper mill sludge reduced it. In fact the rate of emission increased, especially after deep ploughing. | Emissions of N2O are of concern because of the role of this gas in the greenhouse effect and the destruction of the ozone layer. .. emissions from agricultural systems are now thought to contribute 6.2 Tg N2O-N per year to the total global source strength of 17.7 Tg N2O-N per year. |
| 1480 | Baggs, E.M., Rees, R.M., Smith, K.A. & Vinten, A.J.A. | Nitrous oxide emission from soils after incorporating crop residues | 2000 | Greenhouse Gases; Soil N Dynamics | Journal | Soil Use Manag.; 16; 82-87 | English | Hardcopy:Full | Measurement of N2O emissions from soils under different management systems over 54-104 days. The highest total emission occurred after rotary tilling of lettuce residues and the lowest with unfertilised winter wheat. | @; N2O emissions were temporarily raised after .. ploughing of bare soil .., probably due to decomposition of labile root material ..; .. larger emissions were measured after incorporation of material with a low C/N ratio .. The large emissions from lettu |
| 945 | Baggs, E.M., Watson, C.A. & Rees, R.M. | The fate of nitrogen from incorporated cover crop and green manure residues | 2000 | Cover Crops; Green Manure; Soil N Dynamics | Journal | Nutr. Cycl. Agroecosyst.; 56 (2); 153-163 | English | Hardcopy:Partial | Expt. to study the effect on N availability of the incorpor'n of overwintering cover and green crops. Available N, and hence potential N leaching and emission, was reduced compared with bare ground. | Vegetation that had regenerated naturally was as effective as sown cover crops at taking up N over winter & in returning N to the soil for the following crop. |
| 1175 | Bahri, H., Dignac, M.F., Rumpel, C., Rasse, D.P., Chenu, C. & Mariotti, A. | Lignin turnover kinetics in an agricultural soil is monomer specific | 2006 | Lignin and CBW; Soil Organic Carbon | Journal | Soil Biol. Biochem.; 38; 1977-1988 | English | Hardcopy:Partial; Wordperfect:Full | Field expt. to study the turnover kinetics of lignin in an arable soil on a molecular basis | Lignin monomers were released by CuO oxidation .. Individual C4-derived phenols displayed contrasting accumulation rates in soils over time, confirming the monomer-specific nature of their transformation kinetics. In proportion to total lignin phenols in soils, syringyl & cinnamyl phenols from maize accumulated faster than their vanillyl counterparts. Consequently the turnover kinetics of lignin-derived V-moieties may be slower than those of S and C ones. |
| 1505 | Bailey, K.L. & Lazarovits, G. | Suppressing soil-borne diseases with residue management and organic amendments | 2003 | Compost & Biocontrol; Soil Microorganisms | Journal | Soil Tillage Res.; 72; 169-180 | English | Hardcopy:Full; PDF:Full | Review of the effect of organic amendments on soil-borne diseases | .. residue management practices and various forms of organic amendments do contribute to the suppression of soil-borne diseases .. With residue management systems for common root-rot control, crop residue (OM) and its subsequent breakdown results in biological and chemical processes that can directly affect this pathogen's viability and survival through the restriction of available nutrients and the release of natural antimycotic substances with varying inhibitory properties. Carbon released from crop residues contributes to increasing soil microbial activity and so increases the likelihood of competition effects in the soil. The placement of the residue in soil can lead to the displacement of the pathogen from its preferred niche, diminishing the pathogen's ability to survive. The benefits of applying organic amendments for disease control are incremental, generally slower acting than chemical fumigants or fungicides, but may last longer and their effects can be cumulative. |
| 1176 | Bailey, V.L., Smith, J.L. & Bolton, H. | Fungal-to-bacterial ratios in soils investigated for enhanced C sequestration | 2002 | Soil Organic Carbon; Soil Microorganisms; Tillage | Journal | Soil Biol. Biochem.; 34 (7); 997-1007 | English | Hardcopy:Partial | Expt. to assess the relative contributions of fungi and bacteria to microbial biomass and the F/B ratios and activity of soils from various ecosystems, including agricultural land | Within the pairs of study soils those that were tilled had lower fungal activities and stored C [quantities] than those that were managed to native or notill systems. .. soils that had higher absolute fungal activities also had more total soil C & .. fungal activity was correlated with total soil C. .. increased fungal activities, more than F/B ratios, were associated with increased soil C. Practices that involved invasive land management decreased fungal activity & stored soil C compared to similar soils that were less intrusively managed. |
| 1104 | Bais, H.P., Vepachedu, R., Gilroy, S., Callaway, R. & Vivanco, J. | Allelopathy and exotic plant invasion: from molecules and genes to species interactions | 2003 | Allelopathy; Miscellaneous | Journal | Science; 301 (5638); 1377 - 1380 | English | Hardcopy:Full; PDF:Full | Lab. expt. to show that spotted knapweed, an invasive species in western U.S.A., displaces native species by exuding the phytotoxin catechin, which inhibits native species' growth and germination | Plants use sophisticated signal transduction cascades to sense and respond to biotic and abiotic stresses.; ... Ca2+-signalling may play a role in the phytotoxic action of (-)-catechin in susceptible species.; ... the allelochemical triggers a wave of reactive oxygen species initiated at the root (meristem, which leads to a Ca2+ signalling cascade, triggering genome-wide changes in gene expression and ultimately death of the root system. |
| 1400 | Bajracharya, R.M., Lal, R. & Kimble, J.M. | Erosion effects on carbon dioxide concentration and carbon flux from an Ohio alfisol | 2000 | Greenhouse Gases; Soil Organic Carbon; Soil (General) | Journal | Soil Sci. Soc. Am. J.; 64; 694-700 | English | Hardcopy:Partial; Wordperfect:Full | Field expt. to determine the relationshsip between CO2 flux from soil and the degree of erosion | @; Seasonal patterns in soil air CO2 concentrations (ranging from a winter low of 0.56 mL L-1 to a summer high of 20.90 mL L-1) predominated over more subtle differences (20-80% variation) due to erosion phase effects; ..., which appeared to be indirect t |
| 627 | Balabane, M. | Turnover of clay-associated organic nitrogen in the different aggregate-size classes of a cultivated silty loam | 1996 | Mineralisation; Soil N Dynamics | Journal | Eur. J. Soil Sci.; 47 (3); 285-291 | English | Hardcopy:Partial | Expt. using 15N to study the rate of N mineralisation in macro- and microaggregates | .. N mineralisation from macroaggregates is faster than from microaggregates.; Clay-N .. may be protected against degradation within micropores in microaggregates.. N turnover may be faster [also] because of the presence of large fresh plant debris rich in available C that enhances microbial activity.; .. macroaggregates contain additional organic C with a fast turnover compared to microaggregates.; .. material external to both clay- and silt-sized aggregates was largely proteinaceous, while internal material resembled humic acids.; .. recently immobilised N associated with clay is rapidly sequestered in microaggregates. |
| 970 | Baldock, J.A. & Skjemstad, J.O. | Role of the soil matrix and minerals in protecting natural organic materials against biological attack | 2000 | Lignin and CBW; Soil Organic Carbon | Journal | Org. Geochem.; 31 (7-8); 697-710 | English | Hardcopy:Full; PDF:Full | Review of research on the protection of SOM by minerals | OM may range in size and complexity from simple monomers or organic acids to mixtures of complex biopolymers aggregated together in the form of cellular debris.; OM enters the soil as pieces of organic debris having a chem. structure and C/N ratio similar to that of the materials from which they were derived and a particle size >20 m. .. As these organic particles are decomposed, the more labile components of the residues are preferentially utilised and particle size decreases, leading to a conc'n of the more chemically recalcitrant structures (e.g. lignin & alkyl structures) in the 2-20 m size fraction. .. As the content of O-alkyl C decreases, the second stage of decomposition is initiated. Lignin is decomposed, resulting in changes to the chemical structure of the residual lignin polymer and a reduction in the quantity of aromatic C. The decompos'n of lignin is performed [pre]dominantly by fungi.. Lignin degrading organisms do not gain energy or assimilate from lignin degrad'n but benefit through an exposure of labile O-alkyl C buried within lignin/polysaccharide structures. The most biologically stable form of org. C found in soils is alkyl-C. |
| 881 | Baldock, J.A., Masiello, C.A., Gélinas, Y. & Hedges, J.I. | Cycling and composition of organic matter in terrestrial and marine ecosystems | 2004 | Lignin and CBW; Soil Organic Carbon | Journal | Mar. Chem.; 92; 39-64 | English | Hardcopy:Full | Review of recent research into the composition, degradation and stabilisation of the different forms of organic matter in the soil | Microbial utilisation of the carbohydrate-rich and protein-poor litters typical of terrestrial systems generally results in a loss of carbohydrate and an increase in the concentration of protein (due to the immobilisation of inorganic N) and [of] lipid and lignin (due to their greater biochemical recalcitrance). Recalcitrant components such as ... black carbon would also accumulate if present.; Where mechanisms of biological stabilisation are active, organic molecules that are potentially labile may accumulate and be preserved. |
| 628 | Balesdent, J. | The significance of organic separates to carbon dynamics and its modelling in some cultivated soils | 1996 | Soil Organic Carbon | Journal | Eur. J. Soil Sci.; 47 (4); 485-493 | English | Hardcopy:Partial | An expt. to study the turnover of C in various separates from long-term field xexpt.s with maize, using 13C natural abundance measurement | Primary particle-size fractions coarser than 50 m had short lives and could be associated with the plant structural compartment of models. .. None of the chemical separates .. were enriched either in young or old C. .. The results showed neither a sequential relation between fulvic acids and humic acids nor a resistance of non-hydrolysable material. The range of lifetimes of soil C seems to be determined more by physical position and protection than by the chemical nature of SOM. |
| 1177 | Balesdent, J. & Balabane, M. | Major contribution of roots to soil carbon storage inferred from maize cultivated soils | 1996 | Mineralisation; Roots & Rhizodeposition; Soil Organic Carbon | Journal | Soil Biol. Biochem.; 28 (9); 1261-1263 | English | Hardcopy:Full; Wordperfect:Full | Expt. to measure the contribution of roots to the soil storage of C from maize xresidues. The total aboveground production was 730 g C m-2, the harvest index @about 52% and the aboveground residue 380 g C m-2. The belowground biomass was estimated to be 152 g C m-2, giving a root/shoot ratio of 40%. The corresponding quantities of C accumulated in the soil were 57 and 36 g C m-2 yr-1 for root and shoot respectively. | .. the large accumulation [of root-derived material] was partially due to a slower decay of root-derived C compared to aboveground C. .. Two processes are known to lower the decay rate and to increase the stabilisation-to-mineralisation ratio of C in soils: on one hand the higher lignin/N ratio in root material compared to leaves and stalks (i.e. 32 and 11 in the present study respectively) and, on the other hand, the direct introduction of root-derived products into the soil clay matrix, which tends to physically protect them from microbial degradation.; .. maize is known to have a belowground production lower than perennial cereals and grasses .. |
| 1022 | Balesdent, J., Besnard, E., Arrouays, D. & Chenu, C. | The dynamics of carbon in particle-size fractions of soil in a forest-cultivation sequence | 1998 | Soil Organic Carbon | Journal | Plant Soil; 201 (1); 49-57 | English | Hardcopy:Partial; Wordperfect:Full | Study of OM of crop and forest origin in forest and forest-derived arable soils | .. the decay rates of soil C were one order of magnitude higher under cultivation than under forest. .. All size fractions appeared to be de-protected to the same extent. A progressive transfer of silt-sized C to clay-sized C was nevertheless suspected and attributed to the decreasing stability of fine siltsized microaggregates with cultivation.; The turnover times of maize-derived OM [from forest soils first cultivated 40 years ago] was the same as that observed in similar soils cultivated for centuries. This indicated that the new conditions induced by cultivation were reached in the very first years after forest clearing and that the high initial SOM content and high mineralisation rate of initial OM did not affect the dynamics of newly incorporated C. |
| 1506 | Balesdent, J., Chenu, C. & Balabane, M. | Relationships of soil organic matter dynamics to physical protection and tillage | 2000 | Soil Organic Carbon; Tillage | Journal | Soil Tillage Res.; 53 (3-4); 215-230 | English | Hardcopy:Partial | Review of work on the physical protection of OM in soils and the effects of tillage on it. Some of the SOM (mostly from the slow pool of small-sized SOM) is protected from bio-degradation by being included inside microaggregates, which can be dispersed by tillage and weather. | In virgin and zero tillage systems a substantial part of SOM lies above the mineral soil as litter or even in the soil as dead tree stumps.; Cultivating a virgin soil [causes] a drop in SOM concentration .. ranging from 10 to 55% of the native C.; An accumul'n of biological activity and biomass at the surface under NT practices has been reported .. As most SOM is concentrated on the surface, the environment of biodegradation is that of the top few cm. |
| 849 | Balesdent, J., Mariotti, A. & Boisgontier, D. [5 pp. only] | Effect of tillage on soil organic carbon mineralisation estimated from 13C abundance in maize fields | 1990 | Mineralisation; Soil Organic Carbon; Tillage | Journal | J. Soil Sci.; 41; 587-596 | English | Hardcopy:Partial | An expt. using 13C abundance to study the quantity and distribution of maizederived C in soil from a 17-year trial under three different tillage systems | The conventional tillage accumulated 1.1 kg C per sq.m. of maize-derived C and the no-tillage treatment 0.8.; .. mineralisation of the initial organic C during the expt. was doubled in the conventional tillage plot compared with the no-tillage plot. .. Although the mineralisation rate was lower in the no-tillage treatment than in the conventional tillage treatment, the returns of maize C were also lower, so that the final total C content was similar in both treatments. |
| 1178 | Balesdent, J., Mariotti, A. & Guillet, B. | Natural 13C abundance as a tracer for studies of soil organic matter dynamics | 1987 | Soil Organic Carbon | Journal | Soil Biol. Biochem.; 19 (1); 25-30 | English | Hardcopy:Partial | A method is described for measuring the long- and medium-term turnover of SOM, based on the variations of 13C natural isotope abundance induced by the repeated xcultivations of a plant with a high 13C/12C ratio (C4 photosynthetic pathway) on a soil that has never carried any such plant. The method is applied to two soils - one former meadow and one former forest, which had been continuously cropped with maize for 13 and 23 years respectively. 13C is defined as: ((Rsample/Rstandard)1)*1000K, where R is the isotope ratio 13C/12C of the sample. The values of 13C `for atmospheric CO2, C4 plants and C3 plants are about -7K, -12K (range -9 to 19K) and -27K(range -23 to -40K) respectively. The percentage x of C coming from the new C4 plants is calculated from the equation: A = x/100.A1 + (1-x/100.A0),where At is the ratio 13C/(12C + 13C) at time t. | After 13 years 22% of total organic C had turned over in the system studied. |
| 1509 | Ball, B.C. & Ritchie, R.M. | Soil and residue management effects on arable cropping conditions and N2O fluxes under controlled traffic in Scotland 1. Soil and crop responses | 1999 | Soil N Dynamics; Soil (General) | Journal | Soil Tillage Res.; 52 (3-4); 177-189 | English | Hardcopy:Partial; Wordperfect:Full | Partial results of an expt. to study how the intensity and distribution of soil compaction just before sowing @influenced crop performance, soil conditions and emissions of N2O. | Tractor traffic on wet soil can .. increase denitrification by a factor of 34.; Compaction of moist soils is important when air-filled porosity is reduced to below the commonly quoted critical level for satisfactory aeration of 0.1 m3 `m-3. [10%]; Our heavy compaction treatment only caused problems with crop growth when applied to wet soil that remained wet during early growth. This resulted in air-filled porosities of generally less than 0.1 m3 m-3 and cone resistances and bulk densities of nearly 2 MPa and 1.4 Mg m-3 throughout the topsoil. The latter are close to the critical values for barley growth of 2.5 MPa and 1.41 H Mg m-3 on the same soil type .. A critical value of BD of 1.48 Mg m-3 was quoted by Styk and Sochaj (1992) .. |
| 1507 | Ball, B.C., Lang, R.W., Robertson, E.A.G. & Franklin, M.F. | Crop performance and soil conditions on imperfectly drained loams after 20-25 years of conventional tillage or direct drilling | 1994 | Soil (General); Tillage | Journal | Soil Tillage Res.; 31 (2-3); 97-118 | English | Hardcopy:Partial | Expt. to compare soil and yields after long-term ploughing and zero tillage | Soil aeration, strength and structure were more favourable under ploughing than under direct drilling. BD and soil strength did not show any long-term progressive changes in the long-term direct drilled treatment. Weather and drainage status varied markedly between seasons and determined the number of available workdays during the harvesting and tillage period. Available workdays influenced crop responses to reduced tillage more than soil type or physical condition. In some seasons workdays were insufficient to permit the high standard of management necessary for successful reduced tillage, especially direct drilling. |
| 1508 | Ball, B.C., Parker, J.P. & Scott, A. | Soil and residue management effects on cropping conditions and N2O fluxes under controlled traffic in Scotland 2. N2O, soil N status and weather | 1999 | Greenhouse Gases; Soil N Dynamics | Journal | Soil Tillage Res.; 52 (3-4); 191-201 | English | Hardcopy:Partial; Wordperfect:Full | Expt. to assess the effect of xsoil compaction on crop performance and N2O emission. | @; Compaction increases N2O emissions by increasing water-filled porosity and increasing the likelihood of anaerobic soil conditions and denitrification.; Incorporated crop residues can also increase N2O emissions, particularly after ploughing in the autu |
| 1510 | Ball, B.C., Scott, A. & Parker, J.P. | Field N2O, CO2 and CH4 fluxes in relation to tillage, compaction and soil quality in Scotland | 1999 | Greenhouse Gases; Soil N Dynamics; Tillage | Journal | Soil Tillage Res.; 53 (1); 29-39 | English | Hardcopy:Partial; Wordperfect:Full | An expt. to see how tillage practices, soil conditions and weather interact to xinfluence greenhouse gas emissions. CH4 is removed from the atmosphere as a result of oxidation in aerobic soils - the rate of removal is greater in untilled than in tilled soils. N2O emission from soil is increased by synthetic fertiliser or FYM application, by soil compaction and by wet conditions. Rainfall on untilled soil is liable to increase N2O emission and decrease CO2 `emission as a result of reduced porosity and gas diffusivity. The greater CH4 abstraction in zero tillage systems is not enough to compensate for the greater N2O emission. | Periods of low CO2 and high N2O flux under no-tillage were associated with reduced gas diffusivity and air-filled porosity caused by heavy rainfall. |
| 446 | Balota, E.L., Colozzi-Filho, A., Andrade, D.S. & Dick, R.P. | Microbial biomass in soils under different tillage and crop rotation systems | 2003 | Soil Microorganisms; Tillage | Journal | Biol. Fertil. Soils; 38; 15-20 | English | Hardcopy:Full; PDF:Full | 22-year expt. in southern Brasil to effect of tillage and cropping treatments on the microbial biomass in soils. | Averaging across crop rotations in the 0- to 5-cm depth showed a 100%, 54% and 39% increase of MBC, MBN and MBP respectively for NT over CT.; On average NT resulted in an increase of 30% Cmic/Corg percentage over CT.; .. the wider C/N biomass of NT would suggest that NT plots have a greater proportion of fungal compared to bacterial biomass [F/B] than CT. .. reduced soil disturbance favours establishment and maintenance of fungal hyphal networks. |
| 1511 | Balota, E.L., Colozzi-Filho, A., Andrade, D.S. & Dick, R.P. | Long-term tillage and crop rotation effects on microbial biomass and C & N mineralisation in a Brazilian Oxisol | 2004 | Mineralisation; Soil Microorganisms; Tillage | Journal | Soil Tillage Res.; 77; 137-145 | English | Hardcopy:Partial; Wordperfect:Full | Field expts to examine the effect of crop rotation & tillage treatment on C & N mineralisation, microbial biomass C, metabolic quotient & basal respiration | No tillage systems increased total C by 45%, microbial biomass by 83% and MBC/ total C ratio by 23% at 0-50 mm depth over CT. C & N mineralisation increased 74% with NT compared to CT systems for the 0-200 mm depth. Under NT the metabolic quotient (CO2 evolved per unit of MBC) decreased by 32% averaged across soil depths..; No tillage .. increased total C conc'ns over CT by 45, 34 & 14% in (the 0-50, 50-100 & 100-200 mm depths..; Generally .. qCO2 decreases in more stable systems, while the incorporation of residues to soil increases qCO2 .. soils under CT provide less OM and MBC but a larger metabolic quotient than NT.; The values of microbial biomass C/total C varied from 11.6 to 14.8 mg g-1 under H CT & from 11.8 to 16.8 mg g-1 under NT.; The values of basal respiration varied from 5 to 10 g CO2-C g-1 per day under CT and from 5 to 10 g CO2-C g-1 per day under NT ..; On average the C mineralisation under NT was 50% greater than CT.; The values of N mineralisation during 24 days of incubation varied from 0.05 hto 0.09 g N g-1 per day under CT and from 0.07 to 0.22 g N g-1 per day under NT.; On average NT had 78% greater N mineralisation than CT .. |
| 447 | Bardgett, R.D. & McAlister, E. | The measurement of soil fungal:bacterial biomass ratios as an indicator of ecosystem self-regulation in temperate meadow grasslands | 1999 | Organic Farming; Soil Microorganisms | Journal | Biol. Fertil. Soils; 29 (3); 282-290 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the microbial biomass and F/B ratio in fertilised and unfertilised grassland | [title contd. in temperate meadow grasslands]; ... F/B biomass ratios ... were consistently and significantly higher in the unfertilised than the fertilised grasslands. There was also some evidence that microbial biomass ... was higher in the unfertilised than in the fertilised grasslands.; ... soil food-webs of intensive systems were found to be consistently dominated by bacterial pathways of decomposition, whereas soils of long-term organic systems were dominated by fungal pathways. An additional feature of the organically managed grassland soils was a high total microbial biomass, relative to soils of intensive grassland systems.; ... fungi are known to be adversely affected by high amounts of mineral N. |
| 582 | Bardgett, R.D., Denton, C. & Cook, R. | Below-ground herbivory promotes soil nutrient transfer and root growth in grassland | 1999 | Roots & Rhizodeposition; Soil Microorganisms | Journal | Ecol. Lett.; 2; 357-360 | English | Hardcopy:Full; PDF:Full | Lab. expt. to study the effect of nematode root herbivory on white clover plants and on adjacent ryegrass plants | Low levels of white clover root infection by clover cyst nematodes increased root growth by 141% & 219% in the host plant & the uninfected neighbouring [rye]grass respectively. Root infection increased the size of the soil microbial biomass in the root zone and the transfer of 15N from the host plant to the soil & the neighbouring grass. These data suggest that low amounts of below-ground herbivory may increase the transfer of plant C & N below-ground, leading to increases in root growth and soil nutrient recycling in grasslands. |
| 333 | Bardgett, R.D., Streeter, T., Cole, L. & Hartley, I. | Linkages between soil biota, nitrogen availability and plant nitrogen uptake in a mountain ecosystem in the Scottish Highlands | 2002 | Mineralisation; Soil Microorganisms; Soil N Dynamics | Journal | Appl. Soil Ecol.; 19; 121-134 | English | Hardcopy:Partial; PDF:Full | Field expt. to study N mineralisation in a poor acid soil | At the onset of plant growth in May, the microbial N pool was at its lowest (1.8% of total N) and available N was sequestered by the severely N-limited microbial biomass. At this time plant N requirement appears to have been met by the use of internal reserves of N in roots. Significant net mineralisation of N was not detected until microbial demands for N had been satisfied in June. Peak rates of N mineralisation corresponded to maximal plant biomass and shoot N content .. in July, whereas microbial sequestration of N was found to be most intense in late season when plant demands had subsided after senescence. |
| 1179 | Bardgett, R.D., Wardle, D.A. & Yeates, G.W. | Linking above-ground and below-ground interactions: how plant responses to foliar herbivory influence soil organisms | 1998 | Miscellaneous; Soil Microorganisms | Journal | Soil Biol. Biochem.; 30 (14); 1867-1878 | English | Hardcopy:Full; PDF:Full | [title contd.: influence soil organisms (review)] Review of current knowledge of how defoliation of plants can affect the surrounding soil, which happens mainly because defoliation affects carbon allocation and root exudations and also because it affects the quality of plant litter entering the soil. | .. heavy grazing and hence frequent or more severe plant defoliation, favours fast cycles, dominated by labile substrates and bacteria, while light grazing supports slow cycles, dominated by more resistant substrates and fungi. |
| 1617 | Barnes, J.P. & Putnam, A.R. | Evidence for allelopathy by residues and aqueous extracts of rye (Secale cereale) | 1986 | Allelopathy | Journal | Weed Sci.; 34; 384-390 | English | Hardcopy:Partial | Expt. to test the effect of rye on a range of weeds and other plants | Residues of .. rye .. reduced total weed density by 69% and total weed biomass by 32% over a control mulch of poplar excelsior .. [and] reduced total weed biomass by 68% to 95% when compared to controls with no residue.; Under simulated no-till conditions rye residues reduced emergence of lettuce and proso millet by 58% and 35% respectively.; .. allelopathy .. appears to be a viable strategy for weed suppression in agroecosystems. |
| 1180 | Barraclough, D. | The direct or MIT route for nitrogen immobilisation: a 15N mirror image study with leucine and glycine | 1997 | Mineralisation; Soil Microorganisms; Soil N Dynamics | Journal | Soil Biol. Biochem.; 29 (1); 101-108 | English | Hardcopy:Full; PDF:Full | Lab. expt. to test whether N from amino-acids is assimilated by microbes directly (followed by release of surplus N) or whether it follows the MIT route @(complete mineralisation to NH4+, then assimilation by the microbes | The results showed clearly that the conventional MIT route was not operative |
| 709 | Barrett, D.J., Richardson, A.E. & Gifford, R.M. | Elevated atmospheric CO2 concentrations increase wheat root phosphatase activity when growth is limited by phosphorus | 1998 | Phosphorus Cycling | Journal | Funct. Plant Biol.; 25 (1); 87-94 | English | Hardcopy:Partial | An expt. in which wheat seedlings were grown under adequate and limited xphosphorus treatments at ambient and elevated CO2 concentrations. Under P @deficiency and elevated CO2 pressure only, there was an increase in phosphatase activity, which originated from the plant roots rather than from root-associated microorganisms. This phenomenon may increase the rate of mineralisation of soil P with the anthropogenic increase of the atmospheric CO2 content. | |
| 771 | Barrett, P.R.F., Littlejohn, J.W. & Curnow, J. | Long-term algal control in a reservoir using barley straw | 1999 | Miscellaneous | Journal | Hydrobiologia; 415; 309-313 | English | Hardcopy:Partial; Wordperfect:Full | Field expt. to study the effect of loose barley straw on algal growth | Populations of cyanobacteria, diatoms and unicellular green algae in a potable supply reservoir have been suppressed continuously since 1993 by repeated @treatments of barley straw.; 48 g/m3 had rotted in 3 years (approximately 1100 days), so the [mean dail dose] over this period was 0.04 g/d/m3. This .. is an indication of the level of activity of the anti-algal substances released during straw decomposition. .. It also emphasises the importance of applying the straw in a manner which allows decomposition to occur. The disadvantage of applying straw in a form which rots quickly is that it is necessary to repeat the treatments at more frequent intervals, thus adding to the work load. |
| 1181 | Barrios, E., Buresh, R.J. & Sprent, J.I. | Organic matter in soil particle size and density fractions from maize and legume cropping systems | 1996 | Soil Organic Carbon | Journal | Soil Biol. Biochem.; 28 (2); 185-193 | English | Hardcopy:Partial | Lab. study of OM in soil from a 4-year expt. in Kenya, using size-density fractionation, by which the sand-size fraction of the soil is further fractionated by density. The light fraction obtained by flotation of the sandsize fraction (150-3000 m and <1.13 g/cm3) is the fraction most sensitive to change of cropping system. | .. SOM in the sand-size fraction (> 53 m) is often more labile that SOM in the clay- and silt-size fractions. SOM in the sand-size fraction has been termed POM by Cambardella and Elliott. .. during humification parts of SOM become more associated with mineral particles and thus occur in particles of higher density. |
| 1182 | Barrios, E., Buresh, R.J. & Sprent, J.I. | Nitrogen mineralisation in density fractions of soil organic matter from maize and legume cropping systems | 1996 | Mineralisation; Soil N Dynamics | Journal | Soil Biol. Biochem.; 28 (10/11); 1459-1465 | English | Hardcopy:Partial | Lab. study of N mineralisation in size-density fractions of soil from a 4-year expt. in Kenya fractionated by density. The quantity of N in the light fraction @obtained by flotation of the sand-size fraction (150-3000 m and <1.13 g/cm3) correlated with N mineralisation of the whole soil. | Pools with a rapid turnover rate are assumed to have an important role in N availability because SOM dynamics and N cycling are closely linked through the processes of N mineralisation and immobilisation.; While whole-soil N mineralisation provides a measure of available N in the soil, amount of light fraction N may complement this information by providing a relative indication of biologically mediated N availability from labile SOM. |
| 1512 | Basic, F., Kisic, I., Butorac, A., Nestroy, O. & Mesic, M. | Run-off and soil loss under different tillage methods on Stagnic Luvisols in central Croatia | 2001 | Tillage | Journal | Soil Tillage Res.; 62 (3-4); 145-151 | English | Hardcopy:Partial; Wordperfect:Full | Expt. to test the effect of different tillage treatments on soil loss and runoff | .. the conventional up and down the slope ploughing is the least favourable tillage method. It leads to the highest erosion, whereas ploughing across the slope and no-tillage are much more effective in terms of erosion control. |
| 793 | Basic, F., Kisic, I., Nestroy, O., Mesic, M. & Butorac, A. | Particle size distribution (texture) of eroded soil material | 2002 | Tillage | Journal | J. Agron. Crop Sci.; 188; 311-322 | English | Hardcopy:Partial | Study of soil eroded from an erosion-susceptible soil on a slope under six different tillage treatments | .. erosional drift was generally richer in silt and clay particles. .. more silt particles were found in erosional drift than in plot soil. .. the correct choice of tillage (no-tillage and ploughing across the slope) .. can protect the soil on a slope. |
| 629 | Batjes, N. | Total carbon and nitrogen in the soils of the world | 1996 | Greenhouse Gases; Soil Organic Carbon; Soil N Dynamics | Journal | Eur. J. Soil Sci.; 47; 151-163 | English | Hardcopy:Partial | An estimate of the amount of C and N in the world's soils, broken down by region and soil type | Three main reservoirs regulate the C cycle on earth: the oceans (39,000 Pg C), the atmosphere (750 Pg C) and terrestrial systems (2200 Pg C). Although the soil-vegetation C pool is small compared with that of the oceans, potentially it is much more labile in the short term.; Total soil C pools for the entire land area of the world .. amounts to 2157-2293 Pg C in the upper 100 cm. SOC is estimated to be .. 1462-1548 Pg C in the upper 100 cm. .. An estimated 695-748 Pg of carbonate-C is held in the upper 100 cm of the world's soils. .. Global amounts of soil N are estimated to be 133-140 Pg N for the upper 100 cm.; .. about 10 Pg N is held in the plant biomass .. |
| 794 | Battikhi, A.M. & Suleiman, A.A. | Effect of tillage system on soil strength and bulk density of vertisols | 1999 | Tillage | Journal | J. Agron. Crop Sci.; 183 (2); 81-89 | English | Hardcopy:Partial | Expt. to investigate the effect of the type (chisel or mouldboard ploughing) and timing of tillage on the soil strength and BD | Results indicated that R1 [residue incorporation in August] gave significantly higher BD than R2 [residue incorporation in October], while the different tillage treatments had no significant effect. Soil strength was significantly lower under T1 [mouldboard ploughing] and R2 than under the other treatments. |
| 1401 | Bauer, A. & Black, A.L. | Quantification of the effect of soil organic matter content on soil productivity | 1994 | Soil Organic Carbon | Journal | Soil Sci. Soc. Am. J.; 58 (1); 185-193 | English | Hardcopy:Partial | An expt. to measure the effect of SOM content on wheat yields, holding soil water and N content constant | The contribution of 1 Mg OM per ha to soil productivity across the range of 64 to 142 Mg OM per ha was calculated as equivalent to 35.2 kg per ha for spring wheat total serial dry matter and 15.6 kg per ha for grain yield. |
| 1645 | Bayliss-Smith, T.P. | The Ecology of Agricultural Systems | 1982 | Agricultural Ecology | Book | Bayliss-Smith, T.P.; The Ecology of Agricultural Systems; | English | Hardcopy:Partial | Agricultural ecosystems in different parts of the world are described and compared, particularly in respect of their energy inputs and outputs. There are some useful tables of figures, especially on energy expenditure. | .. the effects of the Green Revolution upon crop yields .. have been substantial. This 3-hectare holding [in southern India] .. produced in 1975 57% more food energy than 20 years previously. .. This increased yield has, however, required a 111% increase in energy inputs, partly labour and partly fertilisers, etc. As a result the overall energy ratio has fallen to 9.7 [from 13.0] ..; .. the farmer and his family do less agricultural work than formerly, preferring to employ casual labourers instead. .. the more prosperous farmers are seeing their land as a business rather than a way of life .. |
| 1513 | Bazzofi, P., Pellegrini, S., Rocchini, A., Morandi, M. & Grasselli, O. | The effect of urban refuse compost & different tractors tyres on soil physical properties, soil erosion & maize yield | 1998 | Compost & Biocontrol; Soil (General) | Journal | Soil Tillage Res.; 48 (4); 275-286 | English | Hardcopy:Partial; PDF:Full | 3-year field expt. to test the effect on soil of traffic with low-pressure tyres and of urban-waste compost applied at the maximum permissible rate (64 Mg/ha, which gives 627 kg N, 102 kg P and 384 kg K per ha). Compost decreased run-of and oil erosion, increased soil BD and slightly decreased maize yields compared to chemically fertilised plots. Use of low-pressure tyres reduced soil erosion and compaction and increased maize yields. | The application of a high rate of compost may .. induce negative effects such as soil pollution from heavy metals and plastics residues. It can also result in nitrate losses, particularly in autumn and in the early winter. |
| 1023 | Bearden, B.N. & Petersen, L. | Influence of arbuscular mycorrhizal fungi on soil structure and aggregate stability of a vertisol | 2000 | Soil Microorganisms | Journal | Plant Soil; 218 (1/2); 173-183 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the effect of AM fungi on the soil structure | There are combined effects of increased hyphal length, root growth and presumably microbial activity in the mycorhizosphere on aggregate stability.; .. the effects of mycorrhiza on aggregate stability of a vertisol apparently increased with increasing aggregate size as would be expected according to the hierarchical model for aggregation ..; .. AM fungi had no effect on the amount of particles smaller than 20 m.; .. in situations of good root growth the changed root environment associated with AM fungal colonisation together with the hyphae are responsible for the structural stability. |
| 720 | Beare, M.H. & Bruce, R.R. | A comparison of methods for measuring water-stable aggregates: implications for determining environmental effects on soil structure | 1993 | Soil (General) | Journal | Geoderma; 56 (1/4); 87-104 | English | Hardcopy:Partial | Expt. to compare different methods of fractionating soil, which showed that the stability and size distribution of the aggregates can be strongly influenced by the method of soil pre-treatment. The soils sampled ranged from a loamy sand to a loam, with organic C contents from 6.7 to 24.4 g/kg respectively. | |
| 1183 | Beare, M.H., Blair, J.M. & Parmelee, R.W. | Resource quality and trophic responses to simulated throughfall: effects on decomposition and nutrient flux in no-tillage agroecosystem | 1989 | Mineralisation; Soil Organic Carbon; Soil N Dynamics | Journal | Soil Biol. Biochem.; 21 (8); 1027-1036 | English | Hardcopy:Partial | Expt. to quantify the effects of simulated throughfall additions from rye and clover on soil microorganisms and nutrient fluxes in the soil. Clover residues had greater decomposition rate, net mineralisation, concentration of main nutrients, microbial density and microfaunal densities than rye. | For plant residues with high C/element ratios nutrient immobilisation may dominate over mineralisation until microbial demands are met. .. The importance of exogenous nutrients to net fluxes of elements from decomposing litter has only recently received attention. Two primary sources are recognised: (1) mineral soil pools accessed via fungal hyphal translocation and (2) accumulation of nutrients from bulk precipitation and/or throughfall at the residue surface. |
| 1402 | Beare, M.H., Cabrera, M.L., Hendrix, P.F. & Coleman, D.C. | Aggregate-protected and unprotected organic matter pools in conventional- and no-tillage soils | 1994 | Soil Organic Carbon; Tillage | Journal | Soil Sci. Soc. Am. J.; 58 (3); 787-795 | English | Hardcopy:Partial | An expt. to measure the sizes of different SOM pools in soils under different tillage treatments. The weights of aggregate-protected and unprotected C in the top 15 cm of zero tillage soils were found to be 17.2 and 74.2 g per sq.m. respectively and, in conventionally tilled soils, 8.5 and 74.7 g per sq.m. Macroaggregates are those aggregates in the range 250-2000 m. | .. macroaggregates in NT soils provide an important mechanism for the protection of SOM that may other wise be mineralised under CT practices.; .. macroaggregate-protected pools of C are more labile than the unprotected pools .. unprotected pools of SOM are more exposed and thus more highly processed than the protected pools.; .. smaller microaggregates (53-106 m), presumably .. released during the decay of larger microaggregates, had more labile pools of unprotected C, which are probably derived from previously occluded, less humified OM.; .. largest aggregates (>2000m) .. are the least stable and .. most heavily impacted by cultivation.; Disruption of macroaggregates also markedly reduced N2O emissions in our study. Intact aggregates of NT surface hsamples released much more N2O than those of CT .. |
| 1403 | Beare, M.H., Hendrix, P.F. & Coleman, D.C. | Water-stable aggregates and organic matter fractions in conventional- and notillage soils | 1994 | Soil Organic Carbon; Tillage | Journal | Soil Sci. Soc. Am. J.; 58 (3); 777-786 | English | Hardcopy:Partial | An expt. to study the effects of different tillage systems on water-stable aggregates and aggregate-associated SOM. | Thirteen years of CT and NT .. have resulted in an 18% greater standing stock of SOC in the plough layer (0-15 cm) of NT (30.7 Mg C per ha) than of CT (26.1 Mg C per ha). Because the average annual input of aboveground .. residues were very similar, the differences in SOM content can best be attributed to differences in the assimilation and decomposition of SOM under the two tillage regimes.; In CT macroaggregates (>250m) were fewer and less stable than those of NT.; POM C & N were found .. to be a relatively constant percentage of whole-soil C (36%) and N (34%), regardless of tillage practice.; .. but the quantity of POM was nearly 20% higher in NT than in CT.; .. whole soil POM accounts for much of the SOM lost with cultivation of native sod and .. NT practices can significantly reduce these losses. |
| 334 | Beare, M.H., Hu, S., Coleman, D.C. & Hendrix, P.F. | Influences of mycelial fungi on soil aggregation and organic matter storage in conventional and no-tillage soils | 1997 | Soil Organic Carbon; Soil Microorganisms; Tillage | Journal | Appl. Soil Ecol.; 5; 211-219 | English | Hardcopy:Full; PDF:Full | Expt. to study the influences of fungi on soil properties in soils under different tillage treatments | NT soils retain higher standing stocks of C and have a greater percentage of water-stable macroaggregates than CT soils. Macroaggregates from NT also have higher concentrations of SOM and a much lower dispersion potential than those of CT.; .. densities of total fungal hyphae were significantly higher in NT than in CT. .. bacterial populations were significantly higher in CT ..; .. there is a much greater vertical stratification of fungal populations in NT than in CT soils, where their populations are more uniformly distributed over the profile.; The higher fungal populations of NT were also accompanied by higher concentrations of acid-hydrolysable carbohydrates and a greater contribution of microbial- than plant-derived sugars to the total carbohydrate pool.; .. the influence of fungi on soil aggregation is more directly related to the production and consumption of soil carbohydrates rather than hyphal entanglement.; .. fungi contribute significantly to the stabilisation of soil aggregates, but .. fungal biomass constitutes only a portion of the potentially mineralisable OM associated with aggregates. |
| 561 | Beare, M.H., Parmelee, R.W., Hendrix, P.F. & Cheng, W. | Microbial and faunal interactions and effects on litter nitrogen and decomposition in agro-ecosystems | 1992 | Soil Microorganisms; Soil N Dynamics; Tillage | Journal | Ecol. Monogr.; 62 (4); 569-591 | English | Hardcopy:Partial | Field expts to study the effect of microbial populations on the decomposition of plant litter in conventional and zero tillage systems | .. [the results] indicate a much greater effect of litter placement (surface v. buried) than tillage practice on the compos'n of decomposer communities & on patterns of litter decompos'n & N flux. ..bacteria.. were 7-9.. times greater.. [&] fungi.. 3-4.. times more abundant on buried litter that on surface litter. .. buried litter decompos'n rates averaged 2.5 times higher than those of surface litter..; .. a higher proportion of C [was] channelled through the fungifungivore chain in NT, while C was more equally distributed between fungal and bacterial chains.. in CT.; .. interactions between fungi and fungivorous microarthropods may be responsible for 60% of the net N losses from litter .. over the first 71 days of decay .. |
| 503 | Beauchamp, E.G. | Nitrous oxide emission from agricultural soils | 1997 | Greenhouse Gases; Soil N Dynamics | Journal | Can. J. Soil Sci.; 77 (2); 113-123 | English | Hardcopy:Full | A review of current knowledge of N2O emissions from agricultural soils. Management practices to reduce N2O emissions from agro-ecosystems are listed. | .. there is much uncertainty about the actual contributions of agricultural @practices to global loading of N2O in the atmosphere.; The N2O build-up to 310 ppbv has been attributed to increasing anthropogenic activities ..; .. agriculture's share is presently 81% of anthropogenic N2O emissions.; The effectiveness of N2O as a global warming gas .. is estimated to be more than 250 times that for `CO2.; N2O currently accounts for 2-4% of the total global warming potential, although another recent estimate is as high as 15%.; The denitrification and nitrification processes are the major sources of N2O production in agricultural soils. .. Nitrification is a microbial process requiring aerobic conditions and is dependent primarily on NH4+ supply. .. Denitrification is an anaerobic process carried our by mainly facultative heterotrophic bacteria is dependent on organic C and NO3- (or other N oxides) concentrations.; .. crops recover approximately 50% of the applied N. Also less than 50% of the N in many crops is taken off as grain. ..; .. biologically fixed N should contribute less to global hatmospheric N2O loading than chemically fixed N .. |
| 51 | Beauchamp, E.G. & Hume, D.J. | Agricultural soil manipulation: the use of bacteria, manuring and ploughing | 1997 | Soil Microorganisms; Tillage | Book | Elsas, J.D. van, Trevors, J.T. & Wellington, E.M.H. (eds.); Modern Soil Microbiology; | English | Hardcopy:Partial; Wordperfect:Full | Review of the effects of agricultural operations on bacterial populations and activity in the soil | .. different practices such as tillage methods or manure application affect the size and activities of microbial populations.; Soil conditions for microorganisms are influenced by water content, soil compaction, structure and texture.; .. aerobic microbial activity increases with water content until air diffusion is restricted. Maximum rates of respiration, nitrification and mineralisation occur at the highest water content at which soil aeration remains non-limiting. At about 60% WFP there is a sharp transition to O2-limiting conditions. |
| 853 | Beauchamp, E.G., Voroney, R.P. | Crop carbon contribution to the soil with differing cropping and livestock systems | 1994 | Greenhouse Gases; Soil Organic Carbon; Stockless Farming | Journal | J. Soil Water Conserv.; 49 (2); 205-209 | English | Hardcopy:Full | A mathematical model to estimate the quantity of crop C returned to the soil as FYM on a livestock farm. The harvest index of crops, defined as the usable yield divided by the total biological yield excluding roots, is around 0.4 for wheat, barley and soya beans and 0.5 for maize. The proportion of feed C recovered in manure varies from 0.10 for poultry to 0.40 for non-lactating cattle. | .. more C will remain in the soil at any point in time with livestock manure compared with an equivalent quantity of a leguminous crop.; .. approximately 0.40 of the dry biomass is made up of C.; .. root and exuded C makes up [approximately] 0.20 of the total crop C for [maize, soya beans] and cereal crops. |
| 504 | Beauchemin, S., N'dayegamiye, A. & Laverdière, M.R. | Effets d'apport d'amendements ligneux frais et humifiés sur la production de pomme de terre et sur la disponibilité de l'azote en sol sableux | 1990 | Lignin and CBW; Soil N Dynamics | Journal | Can. J. Soil Sci.; 70 (4); 555-564 | French | Hardcopy:Full | Expt. to study the effect of amending the soil with chipped wood (with or without nitrogenous fertiliser) on the yield of potatoes. In the first year after application of wood chips the potato yield was reduced by 9 t/ha compared with the control. To raise the yield back to the control level it would be necessary to add an additional 1.92 kg N per ton of wood chips applied. In the second year after wood chip application the potato yield was similar to that of the control. | |
| 505 | Beauchemin, S., N'dayegamiye, A. & Laverdière, M.R. | Effets d'amendements ligneux sur la disponibilité de l'azote dans un sol sableux cultivé en pomme de terre | 1992 | Lignin and CBW | Journal | Can. J. Soil Sci.; 72 (2); 89-95 | French | Hardcopy:Full | Field expt. in which potatoes were grown in a soil amended with wood chips or nitrogenous fertiliser or a combination of them both. The decomposition of the wood caused an immobilisation of N, which was not significantly greater with fresh wood chips than with composted ones. By comparing the uptake of N in the case of a plot receiving 150 kg/ha nitrogenous fertiliser alone with that in a plot receiving the same rate of nitrogenous fertiliser plus 50 t/ha of wood chips, it was calculated that an additional 46 kg N/ha would be have to be applied with the wood chips to counterbalance the amount of immobilisation that occurred. | |
| 506 | Beauchemin, S., N'dayegamiye, A. & Laverdière, M.R. | Phytotoxicité des matériaux ligneux frais et compostés utilisés comme amendements organiques de sols | 1992 | Lignin and CBW | Journal | Can. J. Soil Sci.; 72 (2); 177-181 | French | Hardcopy:Full | Expt. to test the effect of fresh and composted tree clippings (mainly from maple, birch, spruce and pine) on the germination of cress seeds | Water-soluble products extracted from fresh ligneous materials decreased the rate of germination of cress very significantly compared with those obtained from composted tree clippings. Grinding the clippings further reduced the germination rate through the apparent liberation of more phytotoxic products.; Les problemes de phytotoxicite sont generalement plus frequents ! partir de residus de coniferes ..; .. les substances toxiques les plus frequemment retrouvees dans la majorite des especes d'arbres sont les tannins et les polyphenols. |
| 1010 | Becana, M., Dalton, D., Moran, J., Iturbe-Ormaetxe, I., Matamoros,M. & Rubio, M. | Reactive oxygen species and antioxidants in legume nodules | 2000 | Green Manure | Journal | Physiol. Plant; 109; 372-381 | English | Hardcopy:Partial; PDF:Full | Review of research into the anti-oxidants that are secreted in the root nodules of leguminous plants to protect them from oxidative stress | Aerobic metabolism is an inherently dangerous process for all organisms. The @risks arise because, although O2 itself is relatively non-reactive, it has the potential to be partially reduced to form reactive oxygen species, including the superoxide radical (O2), hydroxyl radical (OH) and hydrogen peroxide (H2O2). Metabolic processes involving electron transport such as photosynthesis, `respiration and N2-fixation, invariably generate ROS as by-products.; Reactive oxygen species are a ubiquitous danger for aerobic organisms. This risk is especially elevated in legume root nodules due to the strongly reducing conditions, the high rates of respiration, the tendency of leghaemoglobin to autoxidise, the abundance of non-protein Fe and the presence of several redox H proteins that leak electrons to O2. Consequently, nodules are particularly rich in both quantity and diversity of anti-oxidant defences. |
| 49 | Becker, B. | Sustainability assessment: a space and time perspective | 1998 | Sustainability | Book | El Bassam, N., Behl, R.K. & Prochnow, B. (eds.); Sustainable Agriculture for Food, Energy and Industry, vol.1; 19-26 | English | Hardcopy:Full | An analysis of differing approaches to assessing sustainability according to differing space and time scales. System theory is useful in sustainability assessment, which can be done on various levels from plot and farm up to national and global. Indicators of sustainability and the criteria for selecting them are discussed. Sustainability policies are based on different kinds of considerations, according to the scale. | .. for translating sustainability into measurable terms, the spatial and temporal dimensions of the system to be analysed need to be defined ..; .. with increasing scale, policy decisions are more and more normative and value-guided, possibly even irrational, rather than based on hard scientific facts. |
| 807 | Beckett, J.L. & Oltjen, J.W. | Estimation of the water requirement for beef production in the United States | 1993 | Stockless Farming | Journal | J. Anim. Sci.; 71; 818-826 | English | Hardcopy:Partial; PDF:Full | Modelling beef production to estimate direct and indirect water consumption. The model predicts 3,682 l of water per kg of boneless beef, compared with previous estimates of over 20,000 l per kg. Beef cattle were fed an average of 28 kg maize and, in some areas, 23 kg of wheat per year. Average water consumption per animal was 742,000 l per year, comprising 31,500 l drinking water and 710,000 l (mainly) irrigation. At slaughter average bodyweight was 500 kg, dressed carcass was about 60% of bodyweight and boneless beef was 66.7% of carcass. In the U.S. there was 1.9, 2.2 and 3.2 million irrigated hectares of pasture, lucerne and maize respectively. Average calf, heifer and bull weights were 136, 272 and 680 kg respectively. | Irrigation is the major cost of water in U.S. beef production. |
| 1184 | Bedrock, C.N., Cheshire, M.V., Williams, B.L., Solntseva, I., Chapman, S.J., Chudek, J.A. & Goodman, B.A. | Identification of nitrogenous components of fungal and bacterial origin immobilised in decomposing wheat straw by NMR spectroscopy using 15N CPMAS | 1998 | Soil Microorganisms; Soil N Dynamics | Journal | Soil Biol. Biochem.; 30 (1); 113-115 | English | Hardcopy:Full; PDF:Full | One-year field expt. to study the products of microbial immobilisation from wheat straw in mesh bags buried at 6-cm depth in the soil. The biomass in the straw was mainly fungi. | .. the bacterial contribution to the biomass was .. below 5%.; The straw samples when recovered were shown to be enriched to between 2 and 14 atom% N, `indicating transfer of 15N from soil to straw samples. |
| 686 | Beguin, P. & Aubert, J.P. | The biological degradation of cellulose | 1994 | Lignin and CBW | Journal | FEMS Microbiol. Rev.; 13 (1); 25-58 | English | Hardcopy:Partial | Review of the enzymatic degradation of cellulose | Cellulolytic microorganisms play an important role in the biosphere by recycling cellulose, the most abundant carbohydrate produced by plants. Cellulose is a simple polymer, but it forms insoluble, crystalline microfibrils, which are highly resistant to enzymatic hydrolysis. All organisms known to degrade cellulose efficiently produce a battery of enzymes with different specificities, which act together in synergism.; Total hydrolysis of cellulose into glucose, which could be fermented into ethanol .. is not yet economically feasible. |
| 786 | Bekoff, M. | Deep ethology, animal rights and the great ape/animal project: resisting speciesism and expanding the community of equals | 1997 | Agricultural Ethics | Journal | J. Agric. Environ. Ethics; 10 (3); 269-296 | English | Hardcopy:Partial | The evolutionary and comparative study of animal cognition can shed light on questions of animal protection and animal rights. | .. the real question does not deal with whether individuals can think or reason, but rather with whether or not individuals suffer.; .. individuals count and .. it is essential to avoid being speciesist cognitivists ..; Narrowminded primatocentrism and speciesism must be resisted in our studies of animal cognition and animal protection and rights. Line-drawing into 'lower' and 'higher' species is a misleading speciesist practice .. |
| 448 | Bell, J., Smith, J., Bailey, V.L. & Bolton, H. | Priming effect and C storage in semi-arid no-till spring crop rotations | 2003 | Priming Effect; Soil Organic Carbon; Tillage | Journal | Biol. Fertil. Soils; 37 (4); 237-244 | English | Hardcopy:Partial; PDF:Full | Expt. using 14C-labelled straw to study the effect of tillage, crop rotation and crop residue input on the mineralisation of soil C. | .. the frequent addition of crop residue can stimulate C loss through microorganism metabolism and that .. loss may be greater than the loss from tillage.; .. limiting the frequency of residue inputs may help build C in the soil.; .. C inputs have a greater effect on mineralisation of residual C [than] disturbance .. with priming becoming more pronounced as the fungal/bacterial (F/B) ratio in the soil increases.; Bacteria quickly metabolise the soluble C cpds associated with recent residue inputs.. fungi are more efficient at metabolising residual C .. Increases in priming when fungi are more numerous can be attributed to cooperative decomposition with bacteria. In cooperative decomposition fungi break down more resistant C complexes in residues and simpler C compounds become available for bacterial consumption. |
| 29 | Bell, M.A. | Long-term changes in maize yields and soil chemical properties of a tropical Vertisol | 1995 | Soil (General) | Book | Cook, H.F. & Lee, H.C.; Soil Management in Sustainable Agriculture; 140-147 | English | Hardcopy:Full | Field expt. to identify the causes of chlorosis and yield reduction in maize | Three factors are likely to be involved in the increase in ... chlorosis ... and the reduction in yields observed ... (1) a deterioration in soil structure and thus poor drainage; (2) an increase in HCO3- due to release from the chalk subsoil and from ... irrigation water ...; (3) a decrease in root activity or ... rooting depth primarily due to (1) above. |
| 48 | Benbrook, C.M. | Society's stake in sustainable agriculture | 1990 | Sustainability | Book | Edwards, C.A. et al. (eds.); Sustainable Agricultural Systems; | English | Hardcopy:Partial | Sustainable agriculture is defined and conditions for sustainability are detailed:- | 1.; soil resources must not be degraded in quality; ;2.; water resources must be managed in a way .. that crop needs are satisfied; ;3.; the system must be economically viable, returning producers an acceptable profit; ;4.; social expectations and norms must be satisfied; ;5.; the food and fibre needs of the population; [must be satisfied];6.; the biological and ecological integrity of the system must be preserved through management of:.. genetic resources,.. crop pests,.. nutrient cycles,.. and animal health; . |
| 932 | Bending, G.D. | Litter decomposition, ectomycorrhizal roots and the 'Gadgil' effect | 2003 | Soil Microorganisms | Journal | New Phytol.; 158; 228-229 | English | Hardcopy:Full | Review of the Gadgil effect and its implications for litter decomposition | Gadgil & Gadgil .. found that, when ectomycorrhizal roots were excluded from Pinus radiata litter, the rate of litter decomposition increased dramatically. This Gadgil effect was attributed to stimulated colonisation and exploitation of litter by ectomycorrhizal fungi at the expense of litter-decomposing saprotrophs ..; [It] appears to be limited to organic soil horizons, which have a low N availability and .. fluctuations in moisture content. |
| 1185 | Bending, G.D., Turner, M. & Burns, I. | Fate of nitrogen from crop residues as affected by biochemical quality and the microbial biomass | 1998 | Mineralisation; Soil N Dynamics | Journal | Soil Biol. Biochem.; 30 (14); 2055-2065 | English | Hardcopy:Full; PDF:Full | Lab. expt. to study the net mineralisation of N during the decay of various plant residues, including mature leaves and petioles of Brussel sprouts, ryegrass, sugar beet, French beans and potatoes | The quality components controlling net N mineralisation changed during decomposition, with water-soluble phenolic content significantly correlated with net N mineralisation at early stages and water-soluble N, followed by cellulose, at later stages. C/N and total N were correlated with net N mineralisation towards the end of the incubation only. |
| 893 | Benner, R., Fogel, M., Sprague, K. & Hodson, R. | Depletion of 13C in lignin and its implications for stable carbon isotope studies | 1987 | Lignin and CBW; Soil Organic Carbon | Journal | Nature (Lond.); 329; 708-710 | English | Hardcopy:Full; PDF:Full | Lab. expt. to show how the gradual lignin enrichment of plant material as it decomposes in the soil results in a corresponding depletion in its content of naturally occurring C-13 | The structural polysaccharides, cellulose and hemicellulose, account for 57-77% of herbaceous and woody plant tissues. Both cellulose and hemicellulose were typically enriched in 13C by 1-2K relative to whole-plant material.; Lignin accounts for 17-31% of the biomass of woody tissues and 4-9% of the biomass of herbaceous tissues, but contains ca.50% more carbon per unit weight than cellulose and thus accounts for a greater percentage of the total carbon than indicated by a dry weight percentage. ... lignin was depleted in 13C by 2-6K relative to whole-plant material and by 4-7K relative to cellulose.; ... most of the fractionation against 13C which can be measured in lignin occurs during biosynthesis of phenylalanine and tyrosine.; ... under aerobic and anaerobic conditions, the polysaccharide components of vascular plants, such as Spartina, are degraded two to five times more quickly than the lignin component, which results in the gradual enrichment of plant detritus in lignin-derived carbon4-8. |
| 500 | Berg, B., Ekbohm, G., Johansson, M.B., McClaugherty, C., Rutigliano, F. & Santo, A.V. de | Maximum decomposition limits of forest litter types: a synthesis | 1996 | Soil Organic Carbon | Journal | Can. J. Bot.; 74; 659-672 | English | Hardcopy:Partial | Estimating final decomposition levels of forest litter using long-term decomposition data | The limit values estimated varied with litter type. They ranged from about 35% to about 100% decomposition ..; .. although it was possible to estimate .. limit values for litter mass loss by using asymptotic functions, such limit values do not necessarily reflect the proportion of litter that is completely undegradable. .. the estimated proportion could reflect a fraction that is fairly stable but nevertheless decomposes very slowly.; The fact that allophanic OM exists shows that infinite storage is possible .. allophanic OM may be regarded as an extreme case, with high Fe and Al contents .. Good support for non-allophanic long-term storage also exists .. |
| 971 | Bergen, P. van, Bull, I., Poulton, P.R. & Evershed, R.P. | Organic geochemical studies of soils from the Rothamsted Classical Experiments: I. Total lipid extracts, solvent insoluble residues and humic acids from Broadbalk Wilderness | 1997 | Lignin and CBW; Soil Organic Carbon | Journal | Org. Geochem.; 26 (1/2); 117-135 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the lipid, insoluble and humic fractions of SOM | The lipid extracts of soils from the grazed and stubbed areas were markedly different from those from the wooded area and reflected the mixed vegetation cover .. In marked contrast, the pyrolysis data from the insoluble OM & humic fractions of the soils did not reflect the compos'n of the lignin comprising the overlying vegetation, but rather showed evidence of amino acid moieties probably present as polypeptides. The absence of the lignin signal is possibly due to rapid diagenetic changes .. influenced by the slightly alkaline pH of the soil. |
| 162 | Bergkvist, G. | Effect of white clover and nitrogen availability on the grain yield of winter wheat in a three-season intercropping system | 2003 | Clover Sward; Green Manure | Journal | Acta Agr Scand B-S P; 53 (3); 97-109 | English | Hardcopy:Partial | 3-year field expt. to study the effect of undersown white clover on two successive crops of winter wheat | Clover reduced grain yield in the first crop of wheat and increased it in the second.; .. competition from clover needs to be kept small when wheat is at the tillering stage. |
| 721 | Bernoux, M., Cerri, C.C., Neill, C. & Moraes, J.F.L. de | The use of stable carbon isotopes for estimating soil organic matter turnover rates | 1998 | Soil Organic Carbon | Journal | Geoderma; 82; 44-58 | English | Hardcopy:Partial | Review of math'l methods of estimating soil C pools and turnover rates | x; 13C represents approximately 1.11 atom% of the earth's carbon, but biological material varies around this average value as a result of isotopic discrimination during biological .. processes. All plants discriminate against 13C during photosynthesis but to different degrees, depending on their photosynthetic pathway. Stable isotope abundances are expressed .. as the deviation of the isotopic ratio of the sample from that of an arbitrary standard:(aa13C = [(Rsample - Rstandard)/Rstandard] x 1000Kwhere Rsample = 13C/12C in the sample and Rstandard = 13C/12C in the PDB standard(RPDB = 0.0112372). Terrestrial plants with the C3 (Calvin cycle) pathway have 13C values in the range -13 to -20K. Plants with the C4 (Hatch-Slack) pathway H have higher 13C values, ranging from -19 to -9K. The isotopic composition of SOM closely resembles the isotopic composition of the vegetation from which it was derived, because the fractionation during decomposition is small relative to the original fractionation during C fixation. |
| 630 | Besnard, E., Chenu, C., Balesdent, J., Puget, P. & Arrouays, D. | Fate of particulate organic matter in soil aggregates during cultivation | 1996 | Soil Organic Carbon; Tillage | Journal | Eur. J. Soil Sci.; 47 (4); 495-503 | English | Hardcopy:Partial | Expt. using 13C natural abundance to trace what happens to POM from a native forest soil after cultivation | Amongst the several pools of SOM, plant residues i.e. light or POM, is very sensitive to changes in soil management and is rapidly depleted on cultivation of virgin soil.; POM is a labile fraction of SOM which is thought to be physically protected from biodegradation when within soil aggregates.; On cultivation the amount of total POM decreased from 60.9 mg g-1 soil to 54.0 and `19.6 mg g-1 after 7 and 35 years. In all soils most POM was free, i.e. outside stable aggregates, although this proportion decreased from 73 to 58% with cultivation. The loss of POM with cultivation was then due mainly to free POM.; The kinetics of decrease of free and occluded POM from the forest were very different. Free POM decreased very rapidly at the beginning and the decrease was consistent with a loss of 8% per year. Occluded POM decreased only after 7 years and the rate of decrease was about 3% per year. |
| 449 | Bethlenfalvay, G.J., Andrade, G. & Azcón-Aguilar, C. | Plant and soil responses to mycorrhizal fungi and rhizobacteria in nodulated or nitrate-fertilised peas (Pisum sativum L.) | 1997 | Green Manure; Soil Microorganisms | Journal | Biol. Fertil. Soils; 24 (2); 164-168 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the effect of VAM fungi and rhizobacteria on soil aggregate status and on the root and shoot development of a leguminous plant. The microorganisms did not affect shoot development in nodulated plants. With N-fertilised plants the fungus enhanced plant growth, while the bacterium inhibited shoot growth, VAM root colonisation and nodule formation, but enhanced the root/shoot and seed/shoot ratios. | Both the VAM fungus and the rhizobacterium enhanced [the water-stable] aggregation of the soils, in spite of their apparent antagonism.; The two rhizoorganisms affected both plants and soil and these effects were modified by the source of N input - through N fixation or fertilisation. |
| 450 | Bethlenfalvay, G.J., Cantrell, I.C., Mihara, K.L. & Schreiner, R.P. | Relationships between soil aggregation and mycorrhizae as influenced by soil biota and nitrogen nutrition | 1999 | Soil Microorganisms; Soil (General) | Journal | Biol. Fertil. Soils; 28 (4); 356-363 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the effect of mycorrhizal fungi on soil aggregation. The primary influence on aggregate stability was hyphal length. The first 3 weeks were a lag phase in mycorrhizal development, during which bacteria increased, causing a decline in water-stable aggregation. In weeks 3-6 there was a rapid development of mycorrhiza accompanied by a correspondingly rapid increase in WSA. | |
| 1618 | Beyer, L. | The chemical composition of soil organic matter in classical humic compound fractions and in bulk samples - a review | 1996 | Lignin and CBW; Soil Organic Carbon | Journal | Z. Pflanz. Bodenkunde; 159; 527-539 | English | Hardcopy:Partial | Review of recent SOM research with regard to the chemical composition of humus | While it is commonly assumed that humus is primarily formed from the aromatic structures of lignin, the major contribution of long-chain aliphatics to the composition of humus is rarely mentioned. In a summary of research results from the literature the average content of the main components is: 22% aromatic, 25% alkyl, 46% O-alkyl and 10% carboxylic. |
| 451 | Beyer, L., Sieling, K. & Pingpank, K. | The impact of a low humus level in arable soils on microbial properties, soil organic matter quality and crop yield | 1999 | Soil Organic Carbon; Soil Microorganisms | Journal | Biol. Fertil. Soils; 28 (2); 156-161 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the effect of low SOM levels on microorganisms and yields | Microbial biomass C (Cmic) and enzyme activities decreased in soils with a low TOC level ..; The considerably low TOC level is thought to be caused by the intensive cultivation carried out in the last 20 years .. in the last 2 decades the ploughing depth in arable soils has generally increased from 20 to 35 cm .. the rate of SOM decomposition during the last 20 years has increased because of better aeration due to a deep tillage system and a high fertiliser supply, `especially the extremely high N supply of up to 320 kg ha-1 in some years.; .. an annual straw application is not sufficient to regenerate the SOM and to maintain the level of humic compounds.; We found no significant decrease in crop yield in the soils with a low TOC level. |
| 1186 | Biederbeck, V.O., Campbell, C.A., Rasiah, V., Zentner, R.P. & Wen, G.A. | Soil quality attributes as influenced by annual legumes used as green manure | 1998 | Green Manure; Soil (General) | Journal | Soil Biol. Biochem.; 30 (8/9); 1177-1185 | English | Hardcopy:Partial; PDF:Full | 6-yr field expt. to study the effect of increased cropping intensity and of annual legumes on quality | .. most of the soil biochemical & physical attributes assessed were significantly improved (compared to F-W [fallow-heat]) by increasing cropping intensity [continuous wheat] and by using the GM [green manure] systems.; .. soil quality attributes such as C and N mineralisation, wet aggregate stability and light fraction OM were more strongly influenced by the green manure and Cont. W [continuous wheat] systems than was total organic C or N. |
| 795 | Bilalis, D., Efthimiadis, P. & Sidiras, N. | Effect of three tillage systems on weed flora in a 3-year rotation with four crops | 2001 | Tillage | Journal | J. Agron. Crop Sci.; 186 (2); 135-141 | English | Hardcopy:Full; Wordperfect:Full | Field expt.s to determine the effect of different tillage systems on weed populations. The population densities of annual weeds was lowest under zero tillage, while that of perennial weeds was highest. | The highest density and mean dry weight in the first rotation crop were measured under NT because [absence of] tillage did not destroy weeds. In the rotation crops that followed, the lowest mean density and mean dry weight were measured in NT, because germination conditions were not favourable, resulting in the decrease of PF. |
| 1024 | Birkett, M., Chamberlain, K., Hooper, A. & Pickett, J. | Does allelopathy offer real promise for practical weed management and for explaining rhizosphere interactions involving higher plants? | 2001 | Allelopathy | Journal | Plant Soil; 232; 31-39 | English | Hardcopy:Partial; PDF:Full | Review of allelopathic effects and their possible use in weed control | .. allelopathy is any direct or indirect harmful or beneficial effect by one plant (including microorganisms) on another through production of chemical cpds that escape into the environment. .. its effect depends on a chemical cpd being added to the environment. It is thus separated from competition, which involves the removal or reduction of some factor from the environment that is required by some other plant or microorganism sharing the habitat.; .. allelopathy can involve more sophisticated activities in addition to large inundation of the rhizosphere with biocidal material .. & can extend to signalling systems. |
| 1514 | Birkás, M., Jolánkai, M., Gyuricza, C. & Percze A. | Tillage effects on compaction, earthworms and other soil quality indicators in Hungary | 2004 | Tillage | Journal | Soil Tillage Res.; 78; 185-196 | English | Hardcopy:Partial; PDF:Full | Survey of tillage practices in Hungary and their effect on soil compaction and earthworm populations | Seven categories of the subsoil compaction were identified ..according to their depth and characteristics within the soil profile.; .. plough-pan compaction from previous tillage practices was observed at a depth of 25-30 cm. This zone had a penetration resistance of 3.75 MPa. After the third year disc-pan compaction became evident, reaching the critical penetration resistance (3.75 MPa) after the fifth year. The compaction continued to increase during years 7-10, reaching a maximum of 4.6 MPa. Meanwhile the disk-pan became extended to the soil surface because of a reduction in the discing depth. The compaction also became extended to the former plough-pan, resulting in a joint compacted layer at a depth of 17.5-27.5 cm.; .. the soil condition can be improved or maintained by planting a soil-loosening cover crop. However, the loosening effect of the cover crop may not be sufficient to alleviate severe plough-pan compaction if the penetration resistance exceeds 3 MPa and the extent of the compacted layer exceeds 6-8 cm. |
| 1187 | Blagodatskaya, E.V. & Anderson, T.H. | Interactive effects of pH and substrate quality on the fungal-to-bacterial ratio and qCO2 of microbial communities in forest soils | 1998 | Soil Microorganisms | Journal | Soil Biol. Biochem.; 30 (10/11); 1269-1274 | English | PDF:Full; Wordperfect:Full | Field expt. to study the effect of pH & substrate quality on F/B ratios & specific respiration rate in forest soils | Soil pH influenced the percent F/B ratio to a greater degree than substrate and the effect of pH was more pronounced under beech than under spruce. Mean percent F/B respiratory ratios (rounded) of 74 (beech) & 84 (spruce) were found at high pH (ca.6) & ratios of 94 (beech) & 90 (spruce) were found at low pH (ca.3.0) .. `The metabolic quotient qCO2 was strongly affected by soil pH. .. Particularly at (low pH, the qCO2 was higher under spruce as compared to beech. .. With increasing fungal presence the qCO2 declined. The Cmic/Corg ratio was only affected by pH. |
| 335 | Blagodatskaya, E.V., Blagodatsky, S.A., Anderson, T.H. & Kuzyakov, Y. | Priming effects in Chernozem induced by glucose and nitrogen in relation to microbial growth strategies | 2007 | Priming Effect; Soil Microorganisms | Journal | Appl. Soil Ecol.; 37; 95-105 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the relation between priming effect & microbial growth strategy | @; The production of unlabelled extra CO2 induced by glucose was completed after 3 days and amounted to about 15-19% of the microbial biomass-C. The presence of real or apparent PE depended on the level of added C & N. An apparent positive PE was observed |
| 687 | Blake, A. | Rotation is key to conversion without stock [Elm Farm expts.] | 1995 | Stockless Farming | Journal | Farmers Weekly; ; | English | Hardcopy:Full | 10th November edition. The financial and agronomic viability of the 1987-95 Elm Farm trials is briefly reviewed. Under the present set-aside and arable area payments schemes and organic premiums the gross margins are acceptable. | Red clover has a phenomenal ability to accumulate N above ground - [up to] about 400 kg/ha/yr.; Pure red clover is not the most practical .. he advocates a 50/50 clover grass mixture .. worth sacrificing some nitrogen accumulation to keep on top of weeds and boost soil structure.; .. weeds are symptomatic of a poor crop rather than its cause. .. Good establishment is critical [to weed control]. .. combination power harrow/drill boosts establishment and helps young cereals compete with weeds. |
| 205 | Bloem, J., Lebbink, G., Zwart, K.B., Bouwman, L.A., Burgers, S.L.G.E., Vos, J.A. de & Ruiter, P.C. de[abstract only] | Dynamics of microorganisms, microbivores and N mineralisation in winter wheat fields under conventional and integrated management | 1994 | Mineralisation; Soil Microorganisms; Soil N Dynamics | Journal | Agric. Ecosyst. Environ.; 51 (1-2); 129-143 | English | Hardcopy:Partial | Expt. to monitor the changes in microorganisms and available N under conventional and 'integrated' management | Fungal biomass was about 100-fold lower than bacterial biomass. .. Average N mineralisation was 30% higher in INT. The differences are attributed to the approximately 30% higher OM content of INT.; N mineralisation was relatively low in winter. .. Considerable mineralisation rates after harvest confirmed the need for measures to stimulate immobilisation during periods without crop uptake. |
| 52 | Bloem, J., Ruiter, P.C. de & Bouwman, L.A. | Soil food webs and nutrient cycling in agroecosystems | 1997 | Organic Farming; Soil Microorganisms | Book | Elsas, J.D. van, Trevors, J.T. & Wellington, E.M.H. (eds.); Modern Soil Microbiology; | English | Hardcopy:Partial; Wordperfect:Full | Review of experimental work comparing the role of soil organisms in nutrient cycling in conventional and integrated agricultural systems | In natural ecosystems mineralisation of OM is the main source of nutrients for plant growth and there is a reasonable balance between mineralisation and nutrient uptake.; Integrated farming involves a shift from directly feeding the plant with mineral nutrients to feeding the soil organisms with OM, thereby indirectly feeding the plant through nutrient mineralisation by soil organisms. |
| 1188 | Bloem, J., Ruiter, P.C. de, Koopman, G.J., Lebbink, G. & Brussaard, L. | Microbial numbers and activity in dried and rewetted arable soil under integrated and conventional management | 1992 | Soil Microorganisms; Soil N Dynamics | Journal | Soil Biol. Biochem.; 24 (7); 655-665 | English | Hardcopy:Partial | Field expt. to compare the numbers and activity of soil microorganisms in conventional and 'integrated' agroecosystems | @; Under integrated management .. bacterial numbers, O2 consumption and N mineralisation, respectively, were 1.6, 2.1 and 1.8 times higher than under conventional management ..; In contrast with microbial numbers microbial activity was significantly affec |
| 1013 | Blok, W., Lamers, J., Termorshuizen, A. & Bollen, G.J. | Control of soil-borne plant pathogens by incorporating fresh organic amendments followed by tarping | 2000 | Compost & Biocontrol | Journal | Phytopathology; 90 (3); 253-259 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to test the effect on soil pathogens of anaerobic conditions engendered by organic amendments and a plastic cover | After 15 weeks, survival of Fusarium .., Rhizoctonia solani and Verticillium dahliae in inoculum samples buried 15 cm deep was strongly reduced in amended covered plots in both experiments. The pathogens were not or hardly inactivated in amended non-covered soil or non-amended covered soil. |
| 174 | Blombäck, K., Eckersten, H., Lewan, E., Aronsson, H. [abstract only] | Simulations of soil carbon and nitrogen dynamics during seven years in a cover crop expt. | 2003 | Cover Crops; Soil Organic Carbon; Soil N Dynamics | Journal | Agric. Sys.; 76 (1); 95-114 | English | Hardcopy:Partial | This study aimed, with the use of simulation models, to quantify the effect of several years incorporation of cover crop material into the soil on SOM storage, N mineralisation capacity and risk of N leaching. | After 6 years of cover crop treatment, simulated SOM content had increased by less than 2%, but the N-mineralis'n capacity had increased by 25%, corresponding to 37 kg N ha-1. With a continuous annual use of cover crops only a few per cent of the extra mineralised N was leached. Without a succeeding cover crop, however, 30% of N from the increased mineralisation was leached. The results indicated that the decomposition rate increased immediately after frost events. |
| 281 | Blumenthal, J.M., Russelle, M.P. & Lamb, J.F.S. | Subsoil nitrate and bromide uptake by contrasting alfalfa entries | 1999 | Green Manure; Soil N Dynamics | Journal | Agron. J.; 91; 269-275 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the uptake of N from the subsoil by lucerne. There was similar N uptake by all lucerene varieties tested apart from one non-N-fixing areity, which removed 38% more nirtrate from the subsoil than the rest. | @; .. soil inorganic N concentrations and NO3- leaching losses are smaller under deeply rooted perennial crops such as alfalfa than under annual crops such as maize.; .. diverse alfalfa entries differed by up to 20% in N uptake from top-dressed fertiliser |
| 498 | Boadi, D.A., Wittenberg, K.M. & Kennedy, A.D. | Validation of the sulphur hexafluoride (SF6) tracer gas technique for measurement of methane and carbon dioxide production by cattle | 2002 | Greenhouse Gases | Journal | Can. J. Anim. Sci.; 82; 125–131 | English | Hardcopy:Partial | An expt.al comparison of two methods for measuring the CH4 and CO2 production of xcattle. The mean CH4 production was 134 litres per day and the mean CO2 production was 1900 litres per day. | |
| 854 | Boardman, J. | An average soil erosion rate for Europe: myth or reality | 1997 | Soil (General) | Journal | J. Soil Water Conserv.; 53 (1); 46-50 | English | Hardcopy:Full | This paper discredits Pimentel's figure for the soil erosion rate in the United Sates and Europe of 17 tons/ha/year and questions whether an average erosion rate for a whole continent has any validity. | The figure of about 17 t/ha/yr (Pimentel et al. 1995) is of no value, as it is a mean of a range of figures obtained from plot expt..; .. there are independent estimates of erosion rates from field monitoring schemes in Europe that suggest, if we have to use average figures, then 1 and 5 t/ha/yr is a realistic estimate, but that there is considerable variability in space and time. |
| 1636 | Bodruzzaman, M., Meisner, C.A., Hossain, A.B.S., Sadat, M.A. & Amin, M.R. | Tillage options for wheat in Bangladesh | ? | Tillage | Website | English | Hardcopy:Full | Various tillage methods for establishing wheat after rice are discussed, including surface seeding. The yields from surface seeding are comparable with those from conventional tillage and better than those from farmers' practice. | .. surface seeding is the most appropriate technique of wheat cultivation specially in lowland areas where the land has excess moisture .. The optimum moisture for surface seeding is 35%. But it can be determined easily by walking through the field. If the footprint draws water .. that means the soil is at the optimum condition .. Determination of optimum moisture is important. Excess or less moisture may result in poor germination. .. the cow-dung coated seed is broadcast over the field by hand @ 120 kg/ha. | |
| 1025 | Bohlen, P.J., Edwards, C.A. & Edwards, W.M. | Earthworm community structure and diversity in exptal agricultural watersheds in Northeastern Ohio | 1995 | Tillage | Journal | Plant Soil; 170 (1); 233-239 | English | Hardcopy:Partial | Earthworm populations and species were studied in different tillage systems in seven exptal plots over a period of three years. The effects of location, weather and tillage were observed. | The greatest earthworm diversity and highest earthworm population levels occurred in a no-tillage watershed and a watershed that had previously been in ryegrass and long-term no-till. |
| 1026 | Bolan, N.S. | A critical review of the role of mycorrhizal fungi in the uptake of phosphorus by plants | 1991 | Phosphorus Cycling; Soil Microorganisms | Journal | Plant Soil; 134; 189-207 | English | Hardcopy:Partial | Review of the mechanisms for the uptake of P by mycorrhizal fungi | Mycorrhizae .. are formed by most vascular plants except for a few belonging mainly to the Chenopodiaceae, Cruciferae, Cyperaceae, Juncaceae and Proteaceae.; Although soil solution Pi constitutes only a small proportion of total P (<1%), plants derive most of their immediate P requirements from this source. Most of the Pi is adsorbed onto the soil surfaces or precipitated as Fe and Al phosphates in acid soils and as Ca and Mg phosphates in alkaline .. soils.; Organic P occurs as soluble P in soil solution, as insoluble P adsorbed onto soil particles or as a component of SOM. .. inositol phosphate, phospholipids and nucleic acid are the predominant compounds.; In soils with large capacities to adsorb phosphate the rate of release of phosphate from soil particles becomes the major limiting step in the supply of P to plants. |
| 1716 | Bolinder, M.A., Angers, D.A., Giroux, M. & Laverdère, M.R. | Estimating C inputs retained as soil organic matter from corn (Zea Mays L.)? | 1999 | Uncategorised | Journal | Plant Soil; 215; 85-91 | English | PDF:Full | ||
| 6 | Bollen, G.J. & Volker, D. | Phytohygienic aspects of composting | 1996 | Compost & Biocontrol | Book | Bertoldi, M. de, Sequi, P., Lemmes, B., & Papi, T. (eds.); The science of composting; | English | Hardcopy:Partial; Wordperfect:Full | Review of current knowledge of the sanitising aspect of the composting process | The majority of plant pathogens do not survive exposure to conditions prevailing during composting of infested plant residues. The most resistant pathogens are heat-resistant viruses and biotrophic root-infecting fungi. Most soil-borne viruses need nematodes or fungi for infection of the host plant. Since the vectors are destroyed during composting when properly performed, the product is not infectious.; Inactivation and destruction of pathogens is caused by: 1) heat generated during the first phase of composting, 2) toxicity of decomposition products, 3) enzymatic breakdown & 4) microbial antagonism. |
| 1027 | Boller, B.C., Nösberger, J. | Symbiotically fixed nitrogen from field-grown white and red clover mixed with ryegrasses at low levels of 15N-fertilisation | 1987 | Green Manure; Soil N Dynamics | Journal | Plant Soil; 104; 219-226 | English | Hardcopy:Partial | A field study to determine the yield of symbiotically fixed N from clover/grass mixtures. In the seeding year the annual yield of clover N derived from symbiosis averaged 131 and 83 kg/ha with and without N fertiliser respectively. In the first production year the figures were 308 and 232 kg/ha. | .. clover-to-grass transfer of fixed N contributed up to 52 kg N/ha (17 kg N/ha on average) to the N yield of the mixtures.; .. a large proportion of clover in the mixture is necessary for N transfer to become a significant source of N for the grass ..; .. three prerequisites must be met for high yields of fixed N (>200 kg N/ha/yr) in a legume/grass mixture: a) the .. conditions must allow for a forage yield of >10 t DM/ha/yr; b) the proportion of legumes in the mixture must be 50% or higher; c) the legume must obtain 70% or more of its N from symbiotic fixation. |
| 1615 | Bond, W. & Grundy, A.C. | Non-chemical weed management in organic farming systems | 2001 | Miscellaneous; Mulch; Organic Farming | Journal | Weed Res. (Oxf.); 41; 383-405 | English | Hardcopy:Partial; PDF:Full | Review of weed-control methods in organic systems, including mulching and living mulches | A living mulch of Portulaca oleracea (purslane) from seed broadcast before transplanting broccoli suppressed weeds without affecting crop yield. Often the primary purpose of a living mulch is to improve soil structure, aid fertility or reduce pest problems and weed suppression may be merely an added benefit. In cereals an understorey of clover has been shown to improve soil fertility and reduce pest and disease problems in addition to suppressing weeds.; When the growth of a living mulch is not restricted, or when soil moisture is inadequate, even a relatively vigorous crop like potato may suffer from competition and loss of yield. Yield loss was also recorded in transplanted cabbage because of competition for light and moisture with a clover living mulch, but timely mowing of the clover prevented competition in transplanted broccoli.; .. the depth of mulch needed to suppress weed emergence is likely to make transport costs prohibitive unless the material is produced on the farm .. a 3-cm layer of compost was needed to prevent the emergence of annual weeds .. shredded hnewspaper at 0.8-1.4 t ha-1 was effective in suppressing most annual and some perennial weeds in sweet corn, soya bean and tomato. A cut ryegrass mulch spread between planted rows of tomatoes and peppers was more economic than cultivation. .. Organic mulches have the advantage of being biodegradable, but decomposition may result in a temporary reduction in soil mineral N. In addition, the natural phytotoxins released when organic materials decompose may not only inhibit the growth of weeds but also that of the crop plants. |
| 175 | Bonny, S. | Is agriculture using more and more energy? A French case study | 1993 | Energy in Agriculture | Journal | Agric. Sys.; 43; 51-66 | English | Hardcopy:Partial | Energy used in agriculture is compared over the years since 1958. Energy consumed per ton of wheat at the farm gate (specific energy) peaked in the late seventies and, by 1990, had declined to about 1960 levels | n\a |
| 1515 | Borin, M., Menini, C. & Sartori, L. | Effects of tillage systems on energy and carbon balance in north-eastern Italy | 1997 | Energy in Agriculture; Greenhouse Gases; Tillage | Journal | Soil Tillage Res.; 40; 209-226 | English | Hardcopy:Full | Energy and C balances were compared over seven years in three cropping systems with different intensities of tillage - conventional, ridge tillage and noxtillage. The lower fuel consumption and higher SOM content resulted in less CO2 emission into the atmosphere with the conservation tillage methods. On the other hand the average energy costs necessary to produce the unit of production remained more or less constant in the three systems. | Often when farmers change to no-tillage they notice a decreasing yield [which] .. is .. economically greater than the savings obtainable by the reduction in tillage intensity; no-tillage management is also more difficult because of weed control and requires more technical knowledge.; The poor yields obtained until now in no-tillage might be the consequence of less favourable soil conditions (e.g. low porosity, low water storage, low temperature, surface water ponding) owing to the shorter history of these plots, and more weeds.; The energy output is less with the simplified tillage systems because of the lower yield obtained ..; .. the total energy saving is.. 32% with NT.; .. the unploughed treatments have stored a higher amount of organic C in the soil on average than with CT: h.. 770 kg ha-1 yr-1 for.. NT; The average annual consumption of diesel for running the machinery in .. NT was around .. a third of that of CT.. |
| 1189 | Bosatta, E. & Agren, G.I. | Theoretical analysis of microbial biomass dynamics in soils | 1994 | Soil Microorganisms | Journal | Soil Biol. Biochem.; 26 (1); 143-148 | English | Hardcopy:Partial | Modelling the dynamics of soil microbial biomass. The graph of the microbial biomass C/total soil C ratio against the age of the OM declines steeply at first and then levels out, approaching a steady state. | .. soil microbial biomass responds much more rapidly than SOM as a whole to changes in management ..; .. relationships between the microbial biomass C and the soil C .. are dominated by the ratio between microbial growth and microbial mortality. |
| 885 | Bossio, D.A., Scow, K.M., Gunapala, N. & Graham, K.J. | Determinants of soil microbial communities: effects of agricultural management, season and soil type on phospholipid fatty acid profiles | 1998 | Organic Farming; Soil Microorganisms | Journal | Microb. Ecol.; 36; 1-12 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the factors affecting microbial communities in soil under different agricultural management systems | The relative importance of various environmental variables in governing the compos'n of microbial communities could be ranked in the order: soil type > time > specific farming operation (e.g. cover crop incorpor'n or side-dressing with mineral fertiliser) > management system > spatial variation in the field.; Microbial biomass carbon, ... nitrogen and substrate-induced respiration were consistently lower in conventional than in organic and low-input plots. This difference was significant when all sample dates were considered together, but organic and low-input plots did not differ significantly from one another. |
| 336 | Bossuyt, H., Denef, K., Six, J., Frey, S.D., Merckx, R. & Paustian, K. | Influence of microbial populations and residue quality on aggregate stability | 2001 | Soil Microorganisms | Journal | Appl. Soil Ecol.; 16 (3); 195-208 | English | Hardcopy:Full; PDF:Full | Expt. to test the connection between aggregate formation, fungal & bacterial populations and residue quality | Adding mineral nitrogen together with low-quality residue to the soil had a significant negative effect on the formation of large macroaggregates.; There was no significant difference between high-quality and low-quality minus N treatments in the formation of aggregates. This is consistent with the lack of an effect on total biomass and the total carbon .. Bacterial biomass dominated in the high-quality treatment whereas fungal biomass dominated in the low- quality treatment.; fungi have a large influence on macroaggregate formation. Hyphal entanglement is .. the most important contribution of fungi in the formation of aggregates. .. polysaccharide-mediated binding by fungi is largely underestimated. .. bacteria had little influence on aggregate formation. |
| 631 | Bossuyt, H., Six, J. & Hendrix, P.F. | Rapid incorporation of carbon from fresh residues into newly formed stable microaggregates within earthworm casts | 2004 | Soil Organic Carbon | Journal | Eur. J. Soil Sci.; 55 (2); 393-399 | English | Hardcopy:Full; PDF:Full | Field expt. to study the effect of earthworms on aggregate formation | Earthworms helped to form large macroaggregates (>2000 %m). These large macroaggregates contained 4 times more stable microaggregates than those from samples without earthworms.There was more POM within & between microaggregates in macroaggregates in presence of earthworms. The larger amounts of OM [7x more] inside stable microaggregates in casts than in bulk soil after 12 days of incubation `(140mg 13C kg-1 soil compared with 20mg 13C kg-1 soil) indicates that these microaggregates are formed rapidly around freshly incorpor'd residues within casts. |
| 1190 | Bossuyt, H., Six, J. & Hendrix, P.F. | Protection of soil carbon by microaggregates within earthworm casts | 2005 | Soil (General) | Journal | Soil Biol. Biochem.; 37 (2); 251-258 | English | Hardcopy:Full; PDF:Full | Field expt. to determine the effect of earthworms on the formation of soil aggregates and the protection of SOM | ... in the presence of earthworms the C protected by microaggregates within large macroaggregates was a significant pool and 22% of this C pool was newly added C. ... these results clearly indicate the direct involvement of earthworms in providing protection of soil C in microaggregates within large macroaggregates, leading to a possible long-term stabilisation of soil C. |
| 1404 | Bossuyt, H., Six, J. & Hendrix, P.F. | Aggregate-protected carbon in no-tillage and conventional tillage agroecosystems using carbon-14 labelled plant residue | 2002 | Soil Organic Carbon; Tillage | Journal | Soil Sci. Soc. Am. J.; 66 (6); 1965-1973 | English | Hardcopy:Partial; PDF:Full | Field expt. to compare the protection of SOM in surface and sub-surface soils | more young C .. is accumulated in the sub-surface soil of CT than NT, but this C is not stabilised in the long term.. short- and long-term stabilisation of C is higher in the soil surface layers under NT compared with CT. This C stabilisation occurs mainly at the microaggregate level.; The microaggregate- & microwithin-macroaggregate-protected C pools are .. still <5% of the total C pool, indicating that most of the protected C is assoc'd with silt & clay particles. |
| 1516 | Boström, U. | Earthworm populations (Lumbricidae) in ploughed and undisturbed leys | 1995 | Tillage | Journal | Soil Tillage Res.; 35 (3); 125-133 | English | Hardcopy:Partial | A study of earthworm populations in ploughed and undisturbed leys. | Rotary cultivation killed 61-68% of the earthworm biomass. The ploughing that followed increased mortality by a further estimated 12% and 9% .. One year later earthworm abundance in the ploughed treatments was similar to that in the undisturbed lucerne ley .. |
| 1028 | Bottner, P., Pansu, M. & Sallih, Z. | Modelling the effect of active roots on soil organic matter turnover | 1999 | Roots & Rhizodeposition; Soil Organic Carbon | Journal | Plant Soil; 216 (1/2); 15-25 | English | Hardcopy:Partial; PDF:Full | 2-year lab. expt. to compare the decomposition of 14C-labelled plant residues in 2 different soils with and without active root systems | Two .. phases in the decomposition processes .. (1) During the initial fast .. @stage, labile 14C-material stimulated microbial activities and N immobilisation, increasing the 14C-microbial biomass. In the presence of living roots, competition between microorganisms and plants for inorganic N weakly lowered the measured and predicted total 14C mineralisation and resulted in a lower plant productivity [and N uptake] compared to subsequent growths. (2) In contrast, beyond 3-6 months, when the labile material was exhausted, during the slow .. stage, the presence of living roots stimulated the mineralisation of the recalcitrant plant residue-14C in the sandy soil and of the humified-14C in the clay soil.; The presence of roots led to a progressive replacement of the labelled microbial biomass derived from the initial plant material by unlabelled microbial biomass derived from the root deposited carbon. |
| 722 | Bouma, J. & Droogers, P. | A procedure to derive land quality indicators for sustainable agricultural production | 1998 | Soil (General) | Journal | Geoderma; 85; 103-110 | English | Hardcopy:Partial | An attempt to define land quality indicators as the ratio of the actual wheat productivity and the potential productivity given a specified level of risk of nitrate leaching | Land quality was defined by the World Bank as the condition of land relative to the requirements of land use, including agricultural production, forestry, conservation and environmental management.; [According to the] Food and Agricultural Organisation, sustainable land management combines technologies, policies and activities aimed at integrating socio-economic principles with environmental concerns so as to simultaneously maintain and enhance production and services, reduce the level of production risk, protect the potential of natural resources, .. prevent the degradation of soil and water quality, be economically viable and [be] socially acceptable. |
| 1646 | Boustead, I. & Hancock, G. F. | Handbook of Industrial Energy Analysis [2 pp. only] | 1979 | Energy Resources | Book | Boustead, I. & Hancock, G. F.; Handbook of industrial energy analysis; | English | Hardcopy:Partial | The energy content of various materials, artefacts and systems is estimated. | A table gives the energy content of various fuels. |
| 30 | Bowerman, P., Davies, D.B. & Jones, A.E. | The long-term effects of straw incorporation on winter wheat yields | 1995 | Soil (General); Tillage | Book | Cook, H.F. & Lee, H.C.; Soil Management in Sustainable Agriculture; 448-452 | English | Hardcopy:Full | Field expt. to compare the effects of straw burning and chopped straw incorporation by ploughing or discing on winter wheat yields. Some reduction in wheat yield occurred, especially when chopped straw was incorporated by dicing, but generally the loss in yield was insignificant. | ... burning straw was an important aid to sustainable agriculture ... because it ... reduc[ed] grass weed populations [and] made reduced cultivations viable.; ... burning has encouraged the practice of non-plough primary tillage. these techniques are faster than ploughing and usually lead to better quality seedbeds. |
| 372 | Boyle, C.D., Kropp, B.R. & Reid, I.D. | Solubilisation and mineralisation of lignin by white-rot fungi | 1992 | Lignin and CBW; Mineralisation | Journal | Appl. Environ. Microbiol.; 58 (10); 3217-3224 | English | Hardcopy:Partial | Lab. expt. using 14C-lignin labelled wood to quantify the CO2 and water-soluble products formed from lignin under the action of white-rot fungi. Lignin degradation is a two-stage process - first the production of water-soluble products, which then act as precursors for the second stage, the mineralisation of these products to CO2. | .. nutrient N appears to inhibit lignin degradation by all species, although [with some species] this inhibition can easily be masked by its pronounced stimulation of growth.; .. pH and manganese affected lignin degradation by different species differently. |
| 1647 | Boyle, G. | Renewable Energy: Power for a Sustainable Future [1 p. only] | 1996 | Energy Resources | Book | Boyle, G.; Renewable Energy: Power for a Sustainable Future; | English | Hardcopy:Partial | Vegetable oils as a source of energy | Vegetable oils have an energy content of about 37-39 GJ/ton, similar to that of diesel (about 42 GJ/ton) and superior in this respect to ethanol (30 GJ/ ton).; Simple chemical processing of vegetable oil, by 'esterifying', i.e. combining it with ethanol or methanol, leads to a superior diesel substitute, which does not foul engines. |
| 1191 | Bradley, R.L. & Fyles, J.W. | A kinetic parameter describing soil available carbon and its relationship to rate increase in C mineralisation | 1995 | Mineralisation; Priming Effect; Soil Organic Carbon | Journal | Soil Biol. Biochem.; 27 (2); 167-172 | English | Hardcopy:Full | Modelling the mineralisation of SOC. A kinetic parameter AC is proposed as a measure of the available C pool. | .. important nutrients such as N and S mineralise stoichiometrically with C and .. available C is necessary as an energy source for heterotrophic microorganisms.; Living root systems have positive effects on SOM decomposition and the priming of stable native humus compounds in soil. .. Norton etal. estimated the C flow from ponderosa pine seedlings into the bulk soil at >30% (of recently fixed CO2. |
| 1105 | Bradshaw, W. & Holzapfel, C. | Evolutionary response to rapid climate change | 2006 | Miscellaneous | Journal | Science; 312 (5779); 1477 - 1478 | English | Hardcopy:Full; PDF:Full | Review of present knowledge of the reaction of plants and animals to climate change | Over the past 40 yrs species have been extending their ranges toward the poles and populations have been migrating, developing or reproducing earlier in the spring than previously. These range expansions & changes in the timing of seasonal events have generally been attributed to phenotypic plasticity, that is, the ability of individuals to modify their behaviour, morphology or physiology in response to altered environmental conditions. .. However, recent studies show that over the recent decades climate change has led to heritable genetic changes in populations of animals as diverse as birds, squirrels and mosquitoes. |
| 88 | Brandsæter, L.O. & Riley, H.C.F. | Plant residues for weed management in vegetables | 1999 | Clover Sward; Green Manure | Book | Olesen, J.E., Eltun, R., Gooding, M.J., Jensen, E.S & Köpke, U. (eds); Designing & testing crop rotations for organic farming. Proceedings from an international workshop; | English | Hardcopy:Partial; Wordperfect:Full | Field expt. to study the effect of a 3-cm-thick green mulch on weed growth | A main concern in living-mulch cropping systems is yield depression because of competition... An alternative approach, which does not cause such competition problems, is surface mulching with harvested legume material produced on an adjacent area to that of the vegetables.; Both one and two applications of fresh grass-clover mulch controlled weeds germinating from seed, which dominated in this white cabbage experiment. There was little extra benefit from mulching (twice compared to once ..; the mulch levels .. received 1350 g m-2 .. the area needed for mulch production was 2.88 times the area mulched. |
| 422 | Breemen, N. van, Finlay, R., Lundström, U.S., Jongmans, A.G., Giesler, R. & Olsson, M. | Mycorrhizal weathering: a true case of mineral-plant nutrition? | 2000 | Soil Microorganisms | Journal | Biogeochemistry (Dordr.); 49 (1); 53-67 | English | Hardcopy:Partial | Study of ectomycorrhizal fungi in coniferous forests | .. these pores [in rocks under coniferous trees] were formed by .. organic acids exuded by .. mycorrhizal fungi. .. ectomycorrhizal mycelium represents a greatly extended .. surface area for the absorption of nutrients. .. mycelium is able to penetrate, and most probably create, micro-sites, which are inaccessible to plant roots and isolated from bulk soil solution phenomena. Dissolved products could be translocated to the host plant roots, by-passing the soil solution .. and competition for nutrient uptake by other organisms. |
| 723 | Breemen, N. van, Lundstroem, U.S. & Jongmans, A.G. | Do plants drive podsolisation via rock-eating mycorrhizal fungi? | 2000 | Soil Microorganisms | Journal | Geoderma; 94; 163-171 | English | Hardcopy:Partial | Podsols from coniferous forest sites in Finland and Sweden were examined for evidence of fungal participation in soil formation. | Weathering and supply of nutrients derived from minerals to plants is known to be stimulated by plant-symbiotic mycorrhizal fungi. .. ectomycorrhizal fungi drill innumerable narrow cylindrical pores .. into weatherable minerals .. The fungi probably form micropores by exuding strongly complexing low-molecular weight organic acids at their hyphal tips, causing highly local dissolution of aluminium silicates.; In the precipitation/adsorption theory [of podsol formation] water soluble organic acids, mainly relatively high-molecular-weight fulvic acids, derived from partial decomposition of OM .., complex and dissolve Fe and Al from primary and secondary minerals .. |
| 163 | Breland, T.A. | Green manuring with clover and ryegrass cover crops undersown in small grains: crop development and yields | 1996 | Cover Crops; Green Manure | Journal | Acta Agr Scand B-S P; 46; 30-40 | English | Hardcopy:Partial | Field trials to compare cereal monocultures with cereals undersown with three cover crops - Italian ryegrass, white clover and subterranean clover - with and without N fertiliser. The cover crop biomass N at ploughing were 17-94, 37-155 and 41-243 kg N/ha respectively. The grain yields were 83-94%, 84-110% and 84100% of the yields in monoculture. | Loss of main-crop yield frequently occurs with undersowing.; Weeds were reduced by undersowing ..; The mean grain [wheat] yields across N levels .. were 2893, 2852, 4032 and 3227 kg/ha for monoculture, ryegrass, white clover and subterranean clover respectively.; .. up to 50-60 kg/ha of the clover-derived N on the 0-N [unfertilised] plots was potentially plant-available. This is equivalent to 32-39% of white clover biomass N at ploughing.; .. wheat plants were able to utilise the mineralised clover N better than fertiliser N. |
| 452 | Breland, T.A. | Modelling mineralisation of plant residues in soil: effect of physical protection | 1997 | Mineralisation; Soil Organic Carbon; Soil Microorganisms | Journal | Biol. Fertil. Soils; 25 (3); 233-239 | English | Hardcopy:Partial; PDF:Full | Modelling the decomposition of clover residues in soil. In the model the estimated C/N ratio of the microbial biomass had to be reduced from 8 to 6. This may be because the real C/N ratio is initially low (3-4) and gradually increases becasue of succession from bacterial- to fungal-dominated biomass. | |
| 453 | Breland, T.A. & Hansen, S. | Comparison of the difference method and 15N technique for studying the fate of nitrogen from plant residues in soil | 1998 | Allelopathy; Priming Effect; Soil N Dynamics | Journal | Biol. Fertil. Soils; 26 (3); 164-168 | English | Hardcopy:Partial | Lab. expt. to compare two methods of measuring the mineralisation of N from white clover residues in soil under ryegrass. There was evidence of a priming effect by the clover on SON. | .. the clover amendment led to a reduction in plant growth and uptake of N, most likely because of allelopathy ..; Towards the end of the expt. cloverinduced N in the biomass declined .., while mineralised N due to the clover amendment increased .. The results strongly suggest that this increase was caused by a real stimulation of humus N mineralisation by clover amendment .. |
| 507 | Bremer, E., Janzen, H.H. & Johnston, A.M. | Sensitivity of total, light-fraction and mineralisable organic matter to management practices in a Lethbridge soil | 1994 | Green Manure; Organic Farming; Soil Organic Carbon | Journal | Can. J. Soil Sci.; 74 (2); 131-138 | English | Hardcopy:Full | Study of soil samples from a 40-year expt. to determine the effect of various management practices, including native grass and various wheat rotations with or without fallow, nitrate fertiliser, grass/lucerne and FYM. | Light fraction OM accounted for 9-24% of the SOC and 2-17% of the SON.; .. the half-life of LF-OM .. may be similar or somewhat greater than the 2 years (range 1-6 yr) estimated for .. Australian conditions.; .. at least part of the SOM associated with the heavy fraction is also relatively labile. Various studies have indicated that a decomposable pool of SOM is associated with clay-size particles .. |
| 946 | Bremner, J.M. | Sources of nitrous oxide in soils | 1997 | Greenhouse Gases; Soil N Dynamics | Journal | Nutr. Cycl. Agroecosyst.; 49; 7-16 | English | Hardcopy:Full; PDF:Full | Review of current knowledge of the origin on N2O & NO emissions from soil | .. most, if not all, of the N2O evolved from soils is produced by biological processes .. little, if any, is produced by chemical processes such as chemo@denitrification.; .. most of the N2O evolved from soils under aerobic or semianaerobic conditions is produced by nitrifying microorganisms and that most of the N2O evolved from soils under anaerobic conditions is produced by denitrifying microorganisms.; .. most of the NO evolved from soils is not, as initially assumed, produced by denitrifying bacteria during reduction of nitrate but by the chemoautotrophic bacteria responsible for nitrification of ammonium in soils. Production of NO during nitrification in soils usually greatly exceeds production of N2O ..; .. N2O production by nitrifying bacteria in soils is markedly increased by addition of nitrifiable forms of fertiliser N & of plant residues. |
| 610 | Brentrup, F., Küsters, J., Kuhlmann, H. & Lammel, J. | Application of the Life Cycle Assessment methodology to agricultural production: an example of sugar beet production with different forms of nitrogen fertilisers | 2001 | Energy in Agriculture | Journal | Eur. J. Agron.; 14; 221-233 | English | Hardcopy:Partial; PDF:Full | Field expt. to assess the usefulness of LCA in quantifying the environmental impact of agricultural systems | ... the environmental effects of acidification and eutrophication contributed most to the total Eco-indicator value.; ... all analysed fertilising systems particularly contribute to the environmental problems of acidification & eutrophication. This is mainly due to emissions of ammonia and nitrate on the field. |
| 1717 | Bridge P. & Spooner, B. | Soil fungi: diversity and detection | 2001 | Uncategorised | Journal | Plant Soil; 232; 147-153 | English | PDF:Full | ||
| 1648 | Briggs, D. & Courtney, F. | Agriculture and Environment | 1985 | Tillage | Book | Briggs, D. & Courtney, F. ; Agriculture and environment: The physical geography of temperate agricultural systems ; | English | Hardcopy:Partial | Tillage and its effects on the SOM content, biological activity and structural stability are examined. Tillage causes a decline in OM content and reduced biological activity. | .. tillage of grassland soils leads to a slow but persistent decline in the content of OM.; The improved aeration of tilled soil seems to encourage the chemical oxidation of the organic residues ..; Many of the organisms which inhabit the soil are severely affected by tillage.; .. tillage leads to reduced biological activity.; Tillage may directly injure the animals and thus decimate .. their population. |
| 64 | Brinton, W.F. & Evans, E. | Plant performance in relation to oxygen depletion, CO2-rate and volatile fatty acids in container media composts of varying maturity | 2002 | Compost & Biocontrol | Book | Insam, H., Riddech, N. & Klammer, S. (eds.); Microbiology of Composting; | English | Hardcopy:Partial; Wordperfect:Full | Lab. expt. to test the effect of varying compost maturity on the growth of plants in compost-amended media | .. a number of important interrelated factors played a role in determining plant effects arising from immature composts. The causal mechanism was most likely elevated CO2 evolution and VFA [volatile fatty acid] production, elevated ammonia levels, along with oxygen deprivation and hydrogen sulphide production in containers during growth. |
| 972 | Brodowski, S., Rodionov, A., Haumaier, L., Glaser, B. & Amelung, W. | Revised black carbon assessment using benzene polycarboxylic acids | 2005 | Soil Organic Carbon | Journal | Org. Geochem.; 36 (9); 1299-1310 | English | Hardcopy:Partial; Wordperfect:Full | Lab. expt. to test and improve the accuracy of estimates of black carbon in soils | |
| 554 | Brown, M.T. & Herendeen, R.A. | Embodied energy analysis and emergy analysis: a comparative view | 1996 | Energy in Agriculture | Journal | Ecol. Econ.; 19; 219-235 | English | Hardcopy:Full | Review comparing the two methods of quantifying the energy consumption of an agricultural system - embodied energy analysis and emergy analysis | Emergy is defined as the energy of one type (usually solar energy) that is required to produce something. Energies of different types ... are expressed in the equivalent solar energy required to make them. Embodied energy analysis ... uses strictly the heat energy of fuels and does not include environmental energies. The embodied energy in goods and services ... does not include the environmental support that is derived from solar, geophysical and tidal energies that drive all economies.; Energy analysis includes the service input of humans in all evaluations and does so by considering that the work output of humans is one of several multiple outputs and therefore the total emergy support to humans is assigned to their work. Embodied energy analysis routinely does not include human service inputs to processes ... When it does, [it] considers their work output to be only some fraction of the total fuel energy used in their support. |
| 31 | Brown, S.A., Cook, H.F. & McRae, S.G. | Investigations into soil organic matter as affected by organic farming in south-east England | 1995 | Organic Farming; Soil Organic Carbon | Book | Cook, H.F. & Lee, H.C.; Soil Management in Sustainable Agriculture; 189-200 | English | Hardcopy:Partial | Field expt. to compare the organic matter and humic acid contents and the age of the humic acid on organic and conventional arable, horticultural and pasture farms. | The pasture farms ... were characterised by high levels of old ... HA. It was not possible to differentiate between organic and conventional pastures ... The horticultural farms were characterised by ... high levels of young HA ... The organic horticultural farms had higher total SOM levels ... the arable farms had the lowest HA levels, reflecting rare manure applications and frequent tillage. ... The organic arable farms [had] higher SOM levels that the conventional arable farms. |
| 542 | Brown, S.L. & Schroeder, P.E. | Spatial patterns of aboveground production and mortality of woody biomass for eastern U.S. forests | 1999 | Energy Resources | Journal | Ecol. Appl.; 9 (3); 968-980 | English | Hardcopy:Partial | Estimating the aboveground production and mortality of woody biomass (APWB & MWB) of hard- and softwood forests. Root and soil C pools are not included. Fine litter fall (leaves, twigs and reproductive parts) is given as 4.5, 4.0 and 3.2 Mg/ha/yr for hardwood, pine and spruce/fir forest respectively. | APWB for hardwood forests .. averaged 5.2 Mg/ha/yr. For softwood forests APWB .. averaged 4.9 Mg/ha/yr.; For hardwood forests MWB .. averaged 1.1 Mg/ha/yr. The average MWB for softwood forests was 0.6 Mg/ha/yr ..; .. 33% of the preharvested biomass was left as slash.; The amount of dead wood in eastern forests typically ranges from 10% to 20% of the aboveground biomass. .. Rates of decomposition .. can range from 4% to 10% or even higher. |
| 855 | Bruce, J.P., Frome, M., Haites, E., Janzen, H.H., Lal, R. & Paustian, K. | Carbon sequestration in soils | 1999 | Greenhouse Gases; Soil Organic Carbon; Tillage | Journal | J. Soil Water Conserv.; 54 (1); 382-389 | English | Hardcopy:Full | A review of the contribution of improved farming practices to the C sequestration levels in soils | World soils constitute a principal C pool of 1500 to 2000 Pg in SOC and 800 to 1000 Pg as soil inorganic C (SIC) .. Grassland and forest soils tend to lose from 20 to 50% of the original SOC content .. within 40 to 50 years after land use change. .. Estimates of historic loss of SOC from the cultivated soils of the world .. range from 41 Pg to 55 Pg. .. Assuming recovery of 50% of the historic soil loss, the C sequestration potential of world cropland over the next 50 to 100 years may be on the order of 20 to 30 Pg. This equals 7 to 11% of emissions from fossil fuels combustion at 1990 levels over 50 years. Soils of North America account for about 22% of the terrestrial C pool. The total SOC pool to a depth of 1 metre is 267 Pg. for North America .. The cropland area in the United States is about 170 Mha or about 19% of the total land area.; .. adoption of practices with reduced tillage can result in significant accumulation of soil C.; C gains under no-till ranged from -4 to +10 Mg/ha (mean = +3 Mg/ha).; .. the average rate of C accumulation can .. be estimated .. as about 0.3 Mg/ha/year. |
| 808 | Bruckmaier, R.M. & Blum, J.W. | Responses of calves to treadmill exercises during -adrenergic agonist administration | 1992 | Greenhouse Gases | Journal | J. Anim. Sci.; 70; | English | Hardcopy:Partial | Expt. on 24 male Simmental calves to test their reaction to clembuterol at rest and at work. Their bodyweight was 88 kg at the beginning of the expt., 95 kg @after 2 weeks and 138 kg after 6 weeks. The CO2 production was about 0.4 l/min at rest and about 1.2 l/min when walking at 1.5 km/h, rising to about 2 l/min at 3 km/h. | |
| 373 | Bruns, M.A., Stephen, J.R., Kowalchuk, G.A., Prosser, J.I. & Paul, E.A. | Comparative diversity of ammonia oxidiser 16S rRNA gene sequences in native, tilled and successional soils | 1999 | Soil N Dynamics; Tillage | Journal | Appl. Environ. Microbiol.; 65 (7); 2994-3000 | English | Hardcopy:Partial | Expt. to test the effects of soil disturbance on the populations of autotrophic ammonia oxidiser (AAO) bacteria. Compared with native soils tilled soils have higher numbers (but lower genetic diversity) of culturable AAOs, higher nitrate and lower ammonium levels. | Nitrification, the microbial oxidation of ammonium to nitrate, can lead to significant N losses from ecosystems by producing potentially mobile forms of N. .. Although autotrophic nitrification is carried on in two steps by two distinct groups of bacteria, the ammonia oxidisers and nitrite oxidisers, the former is responsible for the rate-determining first step. AAOs thus play a key role in determining whether systems retain or lose N. .. Nitrification rates vary widely in soils and are thought to be controlled principally by ammonium concentration, temperature, moisture and oxygen.; The relatively lower genetic diversity of AAO .. in tilled soils may have been due to repeated ploughing disturbance, which would reduce niche heterogeneity in the soil. |
| 1192 | Bruun, S., Luxhoi, J., Magid, J., Neergaard, A. de & Jensen, L.S. | A nitrogen mineralisation model based on relationships for gross mineralisation and immobilisation | 2006 | Soil N Dynamics | Journal | Soil Biol. Biochem.; 38; 2712-2721 | English | Hardcopy:Partial; PDF:Full | Modelling nitrogen mineralisation and testing the model against the results of lab. incubation expts. | .. the relationship between net N mineralis'n & respiration is largely unaffected by the chemical compos'n of the plant material other than the C/N ratio. This means that the chemical composition of the plant material may primarily influence N mineralis'n through its effect on C mineralisation. |
| 632 | Bruun, S., Thomsen, I.K., Christensen, B.T. & Jensen, L.S. | In search of stable soil organic carbon fractions: a comparison of methods applied to soils labelled with 14C for 40 days or 40 years | 2008 | Soil Organic Carbon | Journal | Eur. J. Soil Sci.; 59; 247-256 | English | Hardcopy:Partial | Lab. expt. to test the effectiveness of various commonly-used methods for the isolation of a stable fraction of SOC | Acid hydrolysis,photo-oxid'n & treatment with a chem. oxidant [NaOCl or Na2S2O8] consistently removed more 40-yr-old C than 40-day-old C, which suggests that the isolated fractions contained a large prop'n of material with a relatively rapid turnover.. The thermal treatment removed more 40-yr-old C than 40-day-old C. |
| 1193 | Buchmann, N. | Biotic and abiotic factors controlling soil respiration rates in Picea abies stands | 2000 | Roots & Rhizodeposition | Journal | Soil Biol. Biochem.; 32 (11/12); 1625-1635 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the factors affecting forest soil respiration rates | .. mineral soil resp'n seemed to contribute a major fraction to the total soil @CO2 flux (>60%)... Microbial resp'n seemed to dominate the respiratory CO2 loss from the forest floor (>70%). |
| 32 | Buckles, D. | Velvetbean in the farming systems of Atlantic Honduras | 1995 | Green Manure | Book | Cook, H.F. & Lee, H.C.; Soil Management in Sustainable Agriculture; 426-434 | English | Hardcopy:Full | Review of the application of velvet beans as a slash-and-mulch green manure crop in Honduras. Use of velvet beans allows annual maize cropping, as compared with 3 maize crops in 7 years in the traditional maize-bush-fallow rotation. | The aggressive legume smothers competing vegetation ... labour dedicated to land preparation is reduced ...; Adopters of velvet bean rotations cultivate on average 40% more winter maize than farmers who do not ...; ... the thick shallow-rooting cover created by velvet bean destroys deeper rooting vegetation and loosens the soil, occasionally provoking landslides during heavy rainfall.; ... the fertiliser effects of velvet beans [are] the most important reason for using the technology ... |
| 600 | Buckley, D.H. & Schmidt, T.M. | Diversity and dynamics of microbial communities in soils from agro-ecosystems | 2003 | Soil Microorganisms | Journal | Environ. Microbiol.; 5 (6); 441-452 | English | Hardcopy:Partial; PDF:Full | Field expt. using ribosomal RNA to study the diversity & dynamics of microbial populations of soils under differing agricultural management | .. long-term mgmnt practices are more likely to influence microbial community compos'n than are contemporary land-use or plant community compos'n.. Temporal changes in microbial community compos'n were observed to occur at scales that are relevant to seasonal events. In addition, it was demonstrated that cultivation has a significant impact on the compos'n of soil microbial communities and that the effects of cultivation on these communities are long lasting. |
| 886 | Buckley, D.H. & Schmidt, T.M. | The structure of microbial communities in soil and the lasting impact of cultivation | 2001 | Soil Microorganisms | Journal | Microb. Ecol.; 42 (1); 11-21 | English | Hardcopy:Partial; PDF:Full | Field expt. to compare the microbial community structures in soils under different agricultural management | Microbial community structure was observed to be remarkably similar among plots that shared a long-term history of agricultural management despite differences in plant community composition and land management that have been maintained on the plots in recent years. In contrast, microbial community structure differed significantly between fields that had never been cultivated and those having a long-term history of cultivation. |
| 930 | Bulson, H.A.J. | Is there life without livestock? | 1996 | Green Manure; Stockless Farming | Journal | New Farmer and Grower; ; | English | Hardcopy:Full | A report of trials of stockless organic rotations at Elm Farm. A one-year red clover ley, cut-and-mulched, gave the highest accumulation of N and the highest yield of a following wheat crop. Wheat after potatoes gives a higher yield than wheat after wheat, probably because (1) the later ploughing of the green manure before the potato crop ensures a greater N accumulation, (2) potato haulm has a lower C/N ratio than wheat straw and therefore is less likely to immobilise N and (3) cultivation between the potato rows to control weeds may stimulate N mineralisation. Soil structure, P and K levels were all maintained and weeds, pest and diseases did not increase. OM levels declined. | .. the rotation design is a critical factor.; Given current levels of direct financial support for arable crops and set-aside, our research indicates that organic stockless systems may be economically viable .. |
| 113 | Bulson, H.A.J., Welsh, J.P., Stopes, C.E. & Woodward, L. | Stockless organic farming in the UK: potential & limits 1988-95 | 1996 | Green Manure; Organic Farming; Stockless Farming | Book | ; Proc. 11th IFOAM Conference, Copenhagen, August 1996; | English | Hardcopy:Full | Financial and agronomic viability of the 1988-95 Elm Farm trials is reviewed. Under the present set-aside and arable area payments schemes and organic premiums the gross margins are acceptable. Weeds, pests and diseases were not a problem. Design of rotations was important. When two successive courses of wheat were grown, the second one did poorly. But, if they were separated by a course of beans, they both did well. Wheat in the third course after red clover and potatoes did particularly well, probably because the clover had a longer growing season before the spring-grown potatoes than before winter wheat and therefore the soil accumulated more N. Also, the inter-row cultivation of the potato crop could have stimulated more rapid mineralisation of the N present. | .. rock phosphate has been applied during the green manure phase .. The level of P and K increased significantly over time across all three rotations .. the level of OM .. declined .. from over 3% to around 2.5%. .. However, .. the expt. was established after a five-year ley when OM levels were high. .. over time the BD of the soil at 12-24 cm. depth reduced .. in all three rotations, although there was no significant relationship in the top 12 cm. .. The maintenance of soil K levels may be the result of .. a clay content of around 18%, which appears to release sufficient K .. |
| 1194 | Bundt, M., Widmer, F., Pesaro, M., Zeyer, J. & Blaser, P. | Preferential flow paths: biological 'hot spots' in soils | 2001 | Soil (General) | Journal | Soil Biol. Biochem.; 33 (6); 729-738 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the biological characteristics of preferential flow paths | The organic C conc'ns were approximately 10-70% higher in the preferential flow paths than in the matrix. The organic N conc'ns were also enriched in the preferential flow paths, as well as the effective cation exchange capacity and the base saturation. Microbial biomass determined with the fumigation-extraction method was 9-92% higher in the preferential flow paths than in the soil matrix. |
| 1382 | Burdon, J. | Are the traditional concepts of the structures of humic substances realistic? | 2001 | Lignin and CBW; Soil Organic Carbon | Journal | Soil Sci.; 166 (11); 752-769 | English | Hardcopy:Partial | Review of the current state of knowledge about the structure of humic substances | .. humic substances are very complex mixtures and .. have no single formula.; .. humic substances are almost entirely mixtures of plant components and microorganism components and their microbial decomposition products.; Humic substances are brown or black and this could occur in several ways ..: (i) char .. (ii) fungal melanins .. (iii) polyquinones .. (iv) some minerals e.g. MnO2.; .. char - black charcoal-like material .. formed by the burning of plant cover.; .. the molecular weight of lignin .. is probably approximately 250,000 daltons. .. the true molecular weight of humic substances is of the order of 1000 .. |
| 156 | Buringh, P. | Organic carbon in the soils of the world | 1984 | Greenhouse Gases; Soil Organic Carbon | Book | Woodwell, G.M. (ed.); The Role of Terrestrial Vegetation in the Global Carbon Cycle: Measurement by Remote Sensing; | English | Hardcopy:Partial | The loss of OM in the world's soils due to forest clearing is estimated. | .. the annual loss of organic C from the world's soils is between 2.5 and 7.4 @x 1015 g, with 4.6 x 1015 g being considered a realistic estimate.; A soil with a BD of 1.5 and a C content of 3% in the 0-25 cm layer, 1% in the 25-50 cm layer, 0.3% in the 50-75 cm layer and 0.1% in the 75-100 cm layer contains 165 t C/ha.; The 1500 x 106 ha of cropland in the world are used to grow food for about four billion people.; The increase in the peat layer is approximately 0.5 mm to 1 mm per year. .. Thus histosols appear to be absorbing approximately 200 x 1012 g C annually. |
| 543 | Burke, I.C., Lauenroth, W.K. & Coffin, D.P. | Soil organic matter recovery in semi-arid grasslands: implications for the Conservation Reserve Programme | 1995 | Soil Organic Carbon; Tillage | Journal | Ecol. Appl.; 5 (3); 793-801 | English | Hardcopy:Full | Expt. to compare the soil properties of natural grassland, fields cultivated for about 50 years and fields that were formerly cultivated but had been abandoned for about 50 years | .. SOM, silt content, microbial biomass, potentially mineralisable N and potentially respirable C were significantly lower on cultivated fields than on native fields. .. Abandoned fields .. were not significantly different from native fields with respect to microbial biomass, potentially mineralisable N or respirable C. .. 50 years is an adequate time for recovery of active SOM and nutrient availability, but recovery of total SOM pools is a much slower process.; Tillage increases erosion and decomposition through physical mixing, degradation of soil aggregates and enhanced contact of litter and interaggregate SOM with decomposing organisms. .. Several decades of continuous cultivation have led to losses in surface SOM .. of between 20% and 40%.; Losses of fine soil particles and total SOM are not likely to be recovered over human time scales, since they represent pools that are accumulated over pedogenetic periods.; .. no-tillage systems have been found to result in a decreased nutrient availability relative to cultivated fields .. and .. a lag in the response of N availability to changes in total or active SOM. |
| 1680 | Burke, J.I., Thomas, T.M. & Finnan, J.M. | Bi-cropping of winter wheat and white clover | 1998 | Clover Sward | Website | http://www.teagasc.ie/research/reports/crops/4316/eopr-4316.asp | English | Hardcopy:Partial; PDF:Full | Field expt. to test the growing of wheat in clover sward. Yields were only about 20% of conventional. | .. early sowing in good conditions is an essential pre-requisite in a bi- cropped production system.; Although grain yields were disappointing beneficial effects of the bi-cropping system were evident. Slug damage to cereals was lower .. and earthworms were more prevalent in bi-cropped areas. .. some evidence was obtained of biological control of aphids .. |
| 374 | Butler, J.L., Williams, M.A., Bottomley, P.J. & Myrold, D.D. | Microbial community dynamics associated with rhizosphere carbon flow | 2003 | Roots & Rhizodeposition; Soil Microorganisms | Journal | Appl. Environ. Microbiol.; 69 (11); 6793-6800 | English | Hardcopy:Partial | Expt. in using 13C-labelled plants to study the way root-deposited photosynthate (rhizodeposition) is cycled in soil microbial communities. Fungi ended up consistently more labelled than bacteria. There was a marked difference in the pattern of labelling between gram-positive and gram-negative bacteria. | .. root-deposited photosynthate serves as an important C source for microorganisms in the vicinity of growing roots. In turn, plant rely on the microbially mediated decomposition of organic materials for their supply of nutrients.; Plant nutrient availability is controlled, to a large extent, by the cycling of this and other organic materials through the soil microbial community. |
| 1718 | Butler, S.J., Vickery, J.A. & Norris, K. | Farmland Biodiversity and the Footprint of Agriculture | 2007 | Uncategorised | Journal | Science; 315; 381-384 | English | PDF:Full | ||
| 454 | Buyanovsky, G.A. & Wagner, G.H. | Changing role of cultivated land in the global carbon cycle | 1998 | Greenhouse Gases; Soil Organic Carbon; Tillage | Journal | Biol. Fertil. Soils; 27; 242-245 | English | Hardcopy:Full; PDF:Full | Review of the published work on the sequestration of C in agricultural soils. It is suggested that cultivated land may constitute the missing C sink in the xworld C balance. Globally there is 1.5 x 109 ha of arable land and 3 x 109 ha of grassland, which together comprise 30% of the earth's land surface. In North America, depending on soil type and weather, 0.15-0.52 Mg ha-1 yr-1 has been sequestered since 1975 as a result of improved cropping. Zero tillage could increase these figures by 15-20%. | Under wheat monocrop (with mineral fertiliser), C accumulated at a rate of 50 (g m-2 year-1 . A 3-year rotation (corn/wheat/clover) with manure and N applications sequestered 150 g m-2 year-1 of C.; Typically 20-40% of the native SOM is lost when virgin lands are converted to agriculture.; Annual productivity of warm season grasses .. is about 4.5 Mg ha-1 C (2.15 Mg of aboveground biomass and 2.35 Mg belowground).; [between 1890 and 1940] .. grain productivity of fertilised wheat increased .. from 0.9-1 to 1.5-1.6 Mg ha-1 year-1 and in the following 50 years it more than doubled to 4.2 Mg ha-1. TNAP [total net annual production] increased from 2-3 Mg C ha-1 in 1950 to 4-5 Mg C ha-1 in 1988. |
| 1406 | Buyanovsky, G.A., Aslam, M. & Wagner, G.H. | Carbon turnover in soil physical fractions | 1994 | Soil Organic Carbon | Journal | Soil Sci. Soc. Am. J.; 58; 1167-1173 | English | Hardcopy:Partial | An expt. using radiocarbon-labelled crops to study the residence time of OM in different fractions of the soil. The residence time increaed with decreasing | The most labile fraction of SOM was plant fragments with turnover time ranging from 1 to 3 years ..The macroaggregates with partially processed C showing turnover from 1 to 3 years contrasted with microaggregates that included more highly humified C having a residence time of about 7 years.; .. aggregates 2 to 1 mm represent only 4 to 5% of total soil mass and <6% of C .. The fraction 1 to 0.5 mm represents about 23 to 25% of the soil and contains about one third of the total C. .. The residence time of C in [this] fraction initially was about 1.5 years .. for the fraction 0.5 to 0.25 mm. the calculated residence time of C is about 3 years or greater.; .. organic C in microaggregates has a residence time of about 7 years.; .. a mean residence time for C in the silt fraction is about 400 years and that for clay is about 1000 years. |
| 337 | Buyer, J.S. & Kaufman, D.D. | Microbial diversity in the rhizosphere of maize grown under conventional and low-input systems | 1996 | Green Manure; Organic Farming; Soil Microorganisms | Journal | Appl. Soil Ecol.; 5; 21-27 | English | Hardcopy:Partial | The 15-year-old Farming Systems Trial at the Rodale Institute compares three treatments - conventional, organic using FYM and organic using leguminous green manure. Soil samples from the rhizosphere were taken from each treatment and compared for diversity and evenness [of distribution ?] of fungi and bacteria. No significant difference was found between the three treatments. This was consistent with the Rodale results reported by Wander, Traina, Stinner et al. (Plant and Soil, 170, 1995). | Soil microbiological diversity has been used as an index for soil quality .. Agricultural management practices might well have an impact on microbial diversity, .. soil health, crop health and yield and sustainability. According to one hypothesis a more complex microbial community will result in greater yield stability. However, there is little direct evidence to support these concepts .. |
| 1174 | Bååth, E. & Anderson, T.H. | Comparison of soil fungal/bacterial ratios in a pH gradient using physiological and PLFA-based techniques | 2003 | Soil Microorganisms | Journal | Soil Biol. Biochem.; 35 (7); 955-963 | English | Hardcopy:Partial; PDF:Full | Field expt. to test the effect of pH on F/B ratios | The biomass-C estimated with SIR was about 0.5% of the SOC in soils with pH 3, but increased to about 2.5% at pH 7.; The F/B ratio measured using the selective inhibition technique decreased significantly with increasing pH from about 9 at pH 3 to approximately 2 at pH 7 ...; Since the selective inhibition method is not a direct measurement of biomass, ... it only provides information about the respiratory activity of the fungal & bacterial components of the total biomass after carbon amendment. It should therefore perhaps be regarded as an activity indicator and the resulting ratio should be called a F/B respiration ratio or a F/B activity ratio. |
| 438 | Bõth, B. & Kling, M. | Root development of leek in a cropping system with red clover | 2001 | Soil N Dynamics | Journal | Biol. Agric. Hortic.; 19 (2); 143-155 | English | Hardcopy:Partial | Field expt. to study the root development of leeks at differing row spacing (0.5 and 0.7 m) after the incorporation of red clover residues into the soil | In the 0-0.15 m soil layer root intensity was higher and lateral distribution more .. in the control .. than in the clover treatment.; Due to the slow lateral root proliferation the N uptake between the rows in the clover treatment with 0.7 m row distance was lower .. As a result higher amounts of mineral N were left between the rows in the [0.7 m clover] treatment, where it constituted a risk of N leaching .. |
| 87 | Bødker, L. & Thorup-Kristensen, K. | Effect of green manure crops on root rot and arbuscular mycorrhizal fungi in pea roots | 1999 | Compost & Biocontrol; Green Manure | Book | Olesen, J.E., Eltun, R., Gooding, M.J., Jensen, E.S & Köpke, U. (eds); Designing & testing crop rotations for organic farming. Proceedings from an international workshop; | English | Hardcopy:Partial; Wordperfect:Full | Field expt. to study the effect of the incorporation of green manures into the soil on root-rot and AM fungi on a subsequent crop of peas | Most reports show a disease-suppressive effect of most org. amendments. .. these 2 years of field trials clearly showed that it is possible both to increase and suppress root pathogens by using green manure crops. Several mechanisms are involved when organic amendments affect occurrence of root diseases. Which ones becomes the most important in a specific situation may berelated to many edaphic factors and the specific pathogens involved. |
| 1405 | Bünemann, E.K., Steinebrunner, F., Smithson, P.C., Frossard, E., Oberson, A. [abstract only] | Phosphorus dynamics in a highly weathered soil as revealed by isotopic labelling techniques | 2004 | Phosphorus Cycling | Journal | Soil Sci. Soc. Am. J.; 68; 1645-1655 | English | Hardcopy:Partial | Soils from two crop rotations (continuous maize and maize-crotolaria) were incubated with a plant residue or with inorganic P. Analysis showed a shift towards microbial P and organic P after plant residue amendment. | |
| 131 | Cadisch, G. & Giller, K.E. | Soil organic matter management: the roles of residue quality in C sequestration and N supply | 2001 | Lignin and CBW; Soil Organic Carbon; Soil N Dynamics | Book | Rees, R.M., Ball, B.C., Campbell, C.D. & Watson, C.A. (eds.); Sustainable Management of Soil Organic Matter; | English | Hardcopy:Partial; Wordperfect:Full | Review of the factors affecting OM transformation in soil | @; .. during the incubation time of 1 year the recalcitrant 13C-depleted lignin did not exert a major influence on the isotopic signature of the remaining material, providing evidence against a direct lignin pathway to SOM formation. It is thus likely tha |
| 1195 | Cadisch, G. & Giller, K.E. | Estimating the contribution of legumes to soil organic matter build-up in mixed communities of C3/C4 plants | 1996 | Green Manure; Soil Organic Carbon | Journal | Soil Biol. Biochem.; 28 (6); 823-825 | English | Hardcopy:Full; PDF:Full | Field expt. to evaluate a method of calculating the contribution of legumes to xSOM accumulation in soil using 13C natural abundance | @; In the pure grass pasture the 13C value of the whole soil was 5-9K smaller than that of the rainforest (-28K) due to the input of C from the C4 grass. The soil 13C values of the grass-legume sward were intermediate between the rainforest and pure grass |
| 1029 | Cadisch, G., Handayanto, E., Malama, C., Seyni, F. & Giller, K.E. | N recovery from legume prunings and priming effects are governed by the residue quality | 1998 | Lignin and CBW; Mulch; Soil N Dynamics | Journal | Plant Soil; 205; 125-134 | English | Hardcopy:Partial; PDF:Full | Lab. study of the effect of legume pruning residue quality on N cycling | .. N recovery from added residues by the first subsequent crop is usually within the range of 10-30% for tropical legume residues.; .. N recoveries from residues in the second and following crop cycles are often only 5% or less of the amount originally applied.; Secondary products of lignin degradation, together with microbial/protein metabolites and polyphenols, are thought to be the main building blocks of SOM ..; .. in legume residues poor quality is associated not so much with low N contents but with large amounts of lignin and/or active polyphenols.; residues high in lignin or active polyphenols .. decompose slowly and contributed little to the plant N uptake in the short term.; .. plant residues rich in N with small lignin contents enhanced crop performance through direct nutritional contributions, whereas residues with high C/N ratio and lignin content do so through mulching effects ..; .. the most reliable predictor of both short- (0-7 wks) and medium-term (8-21 wks) pruning N recovery in this expt. was the ability of the extractable polyphenols to bind proteins.; There was little evidence from our results that slowly decomposing residues increase the soil-residue mineralisation potential in the longer term. |
| 962 | Cairns, M.A., Brown, S.L., Helmer, E.H. & Baumgardner, G.A. | Root biomass allocation in the world's upland forests | 1997 | Energy Resources; Sustainability | Journal | Oecologia; 111 (1); 1-11 | English | Hardcopy:Full; PDF:Full | Calculation of the root/shoot ratio of the world's forests, based on a review of the existing data in the literature. The mean root/shoot ratio for temperate forests was about 0.25.The aboveground biomass density of temperate hardwood forests ranged from 45 to 127 and the belowground from 12 to 30 Mg/ha. | |
| 894 | Calabrese, E. & Baldwin, L. | Toxicology rethinks its central belief: hormesis demands a reappraisal of the way risks are assessed | 2003 | Miscellaneous; Organic Farming | Journal | Nature (Lond.); 421; 692-693 | English | Hardcopy:Full; Wordperfect:Full | Review of approaches to toxicology and health risk assessment, claiming that existing approaches are based on false assumptions and advocating an approach based on hormesis, applicable to all types of toxins | The most fundamental concept used in toxicology to determine risk assessment ... is the dose-response relationship, for which two models have traditionally been used. The threshold model is used in the assessment of risks for noncarcinogens and the linear non-threshold model to extrapolate risks to very low doses of carcinogens. ... the most fundamental shape of the dose response is neither threshold nor linear but U-shaped and hence both current models provide less reliable estimates of low-dose risk. This U-shape is ... called hormesis |
| 153 | Callaghan, T.V., Lawson, G.J., Scott, R. & Whittaker, H.A. | Fuels from non-woody plants | 1981 | Energy Resources | Book | Twidell, J. (ed.); Energy for Rural and Island Communities; | English | Hardcopy:Partial | Figures given for capture of solar radiation by vegetation, including crops grown for bio-fuel. | .. the amount of energy fixed annually by the world's vegetation is about ten times the world's annual use of energy. |
| 724 | Cambardella, C.A. & Elliott, E.T. | Methods for physical separation and characterisation of soil organic matter fractions | 1993 | Soil Organic Carbon | Journal | Geoderma; 56 (1/4); 449–457 | English | Hardcopy:Partial | Expt. to compare different methods for fractionation of soil | The small macroaggregate fraction (250-2000 m) .. contained 52-60% of the total SOC and 51-68% of the total SON. .. no-till management can improve or maintain the macroaggregate structure of cultivated soil .. 18% of the total soil C and 25% of the total soil N was associated with fine-silt-size particles having a density of 2.07-2.22 g cm-3 isolated from inside macroaggregates (enriched labile fraction or ELF). |
| 1408 | Cambardella, C.A. & Elliott, E.T. | Carbon and nitrogen dynamics of soil organic matter fractions from cultivated grassland soils | 1994 | Soil Organic Carbon; Soil N Dynamics | Journal | Soil Sci. Soc. Am. J.; 58 (1); 123-130 | English | Hardcopy:Full | Soil was fractionated by physical methods and the OM in each fraction was quantified in respect of weight, density and rate of mineralisation. One fraction that stood out in terms of the quantity and mineralisability of its organic component was named the 'enriched labile fraction' (ELF). | .. soil was wet-sieved .. to obtain four aggregate fractions: (i) >2000m (large macroaggregates), (ii) 250 to 2000 m (small macroaggregates), (iii) 53 to 250 m (microaggregates) and (iv) <53 m (silt- plus clay-size particles).; We disrupted small macroaggregates and microaggregates into their constituent parts using a probe-type ultrasonic unit.; Four size fractions were isolated from the sonicated small macroaggregates: (i)250 to 2000 m, (ii) 53 to 250 m, (iii) 20 to 53 m and (iv) <20 m. The three smaller size fractions were also isolated from sonicated microaggregates. Fine-silt- and clay-size material were isolated by sequential centrifugation.; Finally they carried out; density flotation of the size fractions to yield discrete size-density fractions, all of which were originally contained within the aggregate structure of the soil.; Twenty percent of the total SOC and 8.5% of the total SON .. was associated with fine-silt-size (2-20 m) particles having a density of 2.07 to 2.22 g/cc. isolated from small macroaggregates. This fraction consistently had the highest percentage of the total SOC & N .. and, because of its properties, will subsequently be referred to as the ELF.; .. the ELF os labile but maybe physically protected from decomposition within the aggregate structure of the soil.; We postulate that the ELF is a by-product of microbial activity ..; The recovered size particles, usually obtained by sedimentation, may consist of an unknown mixture of free OM, primary particles and organo-mineral particles. |
| 201 | Campbell, B.M., Bradley, P. & Carter, S.E. | Sustainability and peasant farming systems: observations from Zimbabwe | 1997 | Sustainability | Journal | Agr. Human Values; 14 (2); 159-168 | English | Hardcopy:Partial | The possibility of assessing the sustainability of peasant farming systems is discussed. | There are problems relating to; selected indicators or performance criteria, spatial scale or boundaries and temporal scale. While there is certainly a need for more rigorous analysis of sustainability issues, there is limited outlook for an approach based on indicators.; Peasant systems are politically guided management systems, whose boundaries are the state, not the field or the farm. |
| 1409 | Campbell, C.A. & Zentner, R.P. | Soil organic matter as influenced by crop rotations and fertilisation | 1993 | Soil Organic Carbon | Journal | Soil Sci. Soc. Am. J.; 57 (4); 1034-1040 | English | Hardcopy:Partial | On a semi-arid prairie site the SOM levels were measured over a 24-year period. SOM was maintained or increased in the case of relatively well-fertilised highyielding crops, but decreased when the crop was poor. | Soils with high initial levels of OM are more likely to show decreases and are more difficult to maintain or increase.; .. roots may be more important than aboveground crop residues in contributing to the maintenance of SOM.; .. the amount of OM in the top 0.15 m depth of soil will vary depending on the amount and N content of the crop residues returned to the land. |
| 508 | Campbell, C.A., McConkey, B.G., Zentner, R.P., Selles, F. & Curtin, D. | Long-term effects of tillage and crop rotations on soil organic C and total N in a clay soil in southwestern Saskatchewan | 1996 | Soil Organic Carbon; Soil N Dynamics; Tillage | Journal | Can. J. Soil Sci.; 76; 395-401 | English | Hardcopy:Partial | The results of an 11-year expt. to study the effect on the soil of various rotations and tillage practices under spring wheat crops. The organic C and total N concentrations were higher in the soil under zero tillage, as was the rate of C sequestration. | |
| 509 | Campbell, C.A., Zentner, R.P., Liang, B.C., Roloff, G., Gregorich, E.G. & Blomert, B. | Organic C accumulation in soil over 30 years in semi-arid south-western Saskatchewan: effect of crop rotations and fertilisers | 2000 | Soil Organic Carbon | Journal | Can. J. Soil Sci.; 80 (1); 179-192 | English | Hardcopy:Partial | Modelling SOC dynamics in the surface soil under various treatments and rotations, including wheat, rye, flax and fallow. The efficiency of conversion of crop residue C to SOC in the 30-year expt.al period averaged 14.1% for all treatments and ranged from 18.1 for the continuous wheat with NP fertiliser to 10.0 for the fallow-wheat-wheat rotation. In the periods 1967-75 and 1990-95 the efficiency for continuous cropping with NP fertiliser averaged 38.0 and 26.5 respectively. In the intermediate period the conversion efficiency was very low, due to very dry weather. | |
| 1164 | Campbell, C.J. & Laherrere, J.H. | The end of cheap oil | 1998 | Energy Resources | Journal | Sci. Am.; 278 (3); 78-83 | English | Hardcopy:Full | Review of the estimates for the size and longevity of available oil reserves | .. within the next decade the supply of conventional oil will be unable to keep up with demand.; From an economic perspective, when the world runs completely out of oil is .. not directly relevant: what matters is when production begins to taper off. .. we conclude that the decline will begin before 2010.; The earth's conventional crude oil is almost half gone.; .. global discovery [of oil] peaked in the early 1960s and has been falling ever since.; There is only so much crude oil in the world and the industry has found about 90 percent of it. |
| 202 | Campbell, M. | Dirt in our mouths and hunger in our bellies: metaphor, theory-making and systems approaches to sustainable agriculture | 1998 | Agricultural Ecology; Sustainability | Journal | Agr. Human Values; 15 (1); 57-64 | English | Hardcopy:Partial | A critique of the concept of sustainable agriculture widely used in current research | The metaphor of the food system dominant in current research approaches to sustainable agriculture mirrors the productionist paradigm, which reduces our relationship to land and food to the production and consumption of commodities. The enactment of the familiar values of nourishment and hospitality is what the goal of sustainable agriculture would amount to in terms of our day-to-day lived experience. |
| 89 | Campiglia, E., Caporali, F., Bàrberi, P. & Mancinelli, R. | Influence of 2-, 3-, 4- and 5-year stands of alfalfa on winter wheat yield | 1999 | Green Manure | Book | Olesen, J.E., Eltun, R., Gooding, M.J., Jensen, E.S & Köpke, U. (eds); Designing & testing crop rotations for organic farming. Proceedings from an international workshop; | English | Hardcopy:Partial; Wordperfect:Full | Field expt. to test the suitablity of lucerne as a green manure for wheat | .. a satisfactory winter wheat yield can be achieved without any mineral N fertilisation, provided that [lucerne] is grown as a preceding crop for a minimum of 3 years.; One of the major effects of alfalfa is its well-known ability to fix symbiotically large amounts of atmospheric N, most of which is carried over to succeeding crops. The amount of N fixed can range from 174 kg `N ha-1 in the first growing year to 466 kg N ha-1 in the third year. |
| 1518 | Cannell, R.Q. & Hawes, J.D. | Trends in tillage practices in relation to sustainable crop production with special reference to temperate climates | 1994 | Tillage | Journal | Soil Tillage Res.; 30 (2-4); 245-282 | English | Hardcopy:Partial | Review of tillage practices in relation to the concept of sustainability | Conservation tillage practices can increase the OM content, aggregate stability and cation exchange capacity (CEC) of the topsoil. However, BD and penetrometer resistance are also increased, especially with zero tillage. .. in some soils biopore formation in zero or minimally tilled land can modify the soil for water movement and for root growth and function.; In Europe, yields of winter cereals have also been similar after traditional and simplified tillage but yields of spring cereals have sometimes been less after direct drilling than ploughing.; In Europe although erosion is less obvious it is believed to be increasing, but minimum tillage is not widely used. This is because of the need to remove at least some straw for successful minimum tillage .. In the more moist cooler conditions of Europe grass weed proliferation is another constraint .. |
| 313 | Carpenter-Boggs, L., Reganold, J.P. & Kennedy, A.C. | Biodynamic preparations: short-term effects on crops, soils and weed populations | 2000 | Biodynamic Farming | Journal | Am. J. Alternative Agr.; 15 (3); 110-118 | English | Hardcopy:Partial; Word:Full | Field expt. to study the effect of biodynamic preparations on crops & soil | Crop yield, crop quality and soil fertility were similar in plots treated with mineral NPK fertilisers, biodynamic compost or non-biodynamic compost.; Biodynamic sprays altered soil and grain N chemistry, but the effects are of unknown biological significance.; In general, soils and crops treated with biodynamic preparations showed few differences from those not treated. Application of composts with or without the preparations produced similar crop yields ... but any additional short-term benefits from biodynamic prep's remain questionable. |
| 439 | Carpenter-Boggs, L., Reganold, J.P. & Kennedy, A.C. | Effects of biodynamic preparations on compost development | 2000 | Biodynamic Farming; Compost & Biocontrol | Journal | Biol. Agric. Hortic.; 17; 313-328 | English | Hardcopy:Partial; Wordperfect:Full | Field expt. to study the effect of biodynamic additives on composting | Biodynamic-treated composts maintained an average 3.4$C higher temp throughout xthe eight-week active composting period ..; BD-treated piles respired CO2 at a @10% lower rate & had a larger ratio of dehydrogenase enzyme activity to CO2 production.; Final samples of BD-treated composts also had 65% more nitrate than control piles. Biodynamic prep'ns thus effect discernable changes in compost chem. & microbial parameters.; BD compost does not need to be turned. |
| 1410 | Carpenter-Boggs, L., Reganold, J.P. & Kennedy, A.C. | Organic and biodynamic management: effects on soil biology | 2000 | Biodynamic Farming; Organic Farming; Soil Microorganisms | Journal | Soil Sci. Soc. Am. J.; 64; 1651-1659 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the effects of biodynamic prep'ns on soil microorganisms | Both biodynamic and non-biodynamic composts increased soil microbial biomass, respiration, dehydrogenase activity, soil C mineralised in 10 d (MinC), earth@worm population & biomass & qCO2 .. No significant differences were found between soils fertilised with biodynamic vs. non-biodynamic compost. Use of biodynamic field sprays was associated with more MinC & minor differences in soil microbial fatty acid profiles .. There were no other observed effects of the biodynamic prep'ns. Organically & biodynamically managed soils had similar microbial status & were more biotically active than soils that did not receive org. fertilis'n. Org. mgmt enhanced soil biological activity, but additional use of the biodynamic prep'ns did not significantly affect the soil biotic parameters tested. |
| 1519 | Carpenter-Boggs, L., Stahl, P.D., Lindstrom, M.J. & Schumacher, T.E. | Soil microbial properties under permanent grass, conventional tillage and notill management in South Dakota | 2003 | Soil Microorganisms; Tillage | Journal | Soil Tillage Res.; 71 (1); 15-23 | English | Hardcopy:Partial | Expt. to determine how zero- and conventional tillage affect the microbial properties of the soil, as compared with permanent grassland. | Most measures of microbial activity were similar in the two annually cropped management systems but [very much] less than under permanent grass.; Soils managed under permanent grass contained approximately 160% greater labile C and 50% greater microbial biomass and supported approximately 150% greater dehydrogenase enzyme activity, 50% greater respiration and 180% greater acid phosphatase activity than no-till and conventionally tilled soils, which were similar in these measures.; .. only alkaline phosphatase activity and C mineralised in 12 days were significantly different under no-till and conventional tillage, both greater under no-till. |
| 566 | Carreiro, M.M., Sinsabaugh, R.L., Repert, D.A. & Parkhurst, D.F. | Microbial enzyme shifts explain litter decay responses to simulated nitrogen deposition | 2000 | Lignin and CBW; Soil Microorganisms | Journal | Ecology; 81 (9); 2359-2365 | English | Hardcopy:Full; PDF:Full | Field (litter-bag) expt. to measure the effect of simulated N deposition (20 and 80 kg N/ha/yr) on the enzyme activity of soil microorganisms | .. natural systems near industrialised and agricultural areas .. receive N inputs of up to 60 kg/ha/yr, compared with fluxes of 0.5 to 2 kg N/ha/yr at more isolated sites.; .. N deposition may be having a negative impact on the ligninolytic activity and perhaps abundance of white rot fungi ..; For the lowlignin dogwood litter both the high and low N additions increased the litter decay-rate coefficient by 26% .. for the high-lignin oak litter the low and high N treatments depressed the decay rate coefficient by 15% and 25% respectively, increasing the litter mean residence time from 3.4 yr to 4.0 yr and 4.5 yr. |
| 539 | Carrión, J.S., Parra, I., Navarro, C. & Munuera, M. | Past distribution and ecology of the cork oak (Quercus suber) in the Iberian Peninsula: a pollen-analytical approach | 2000 | Miscellaneous | Journal | Divers. Distrib.; 6 (1); 29-44 | English | Hardcopy:Partial; PDF:Full | Review of the palynological evidence for the past distribution of the cork oak | ... the cork oak survived regionally during the Upper Pleistocene and was important during a mid-Holocene replacement of a local pine forest by Quercusdominated communities. This phenomenon appears linked to the recurrence of fire and reinforces the value of the cork oak for reforestation programmes in fireprone areas.; Q. suber and Q. ilex often replace deciduous Quercus forests after the first evidence of human action. ... it can be detected as an anthropogenically induced succession towards Q. suber and P. pinaster and its fire-derived understorey Phillyrea. |
| 132 | Carter, M.R. | Organic matter and sustainability | 2001 | Soil (General); Sustainability | Book | Rees, R.M., Ball, B.C., Campbell, C.D. & Watson, C.A. (eds.); Sustainable Management of Soil Organic Matter; | English | Hardcopy:Partial; Wordperfect:Full | Review of factors affecting soil sustainablity | In contrast to natural ecosystems, agroecosystems are open and complex, with major exports of primary production (i.e. harvest) and inputs of nutrients and energy, and have additional economical and sociological components with their own driving variables (e.g. demands of society for agricultural goods). |
| 282 | Carter, M.R. | Soil quality for sustainable land management: organic matter and aggregation interactions that maintain soil functions | 2002 | Soil (General) | Journal | Agron. J.; 94; 38-47 | English | Hardcopy:Partial; PDF:Full | Review of the factors contributing to the concept of soil quality. The estimated turnover times for SOM fractions is: litter, 0.5-2 yrs; microbial biomass, 0.10.4 yrs; POM, 1-8 yrs; LF, 1-15 yrs; OM in macroaggregates, 1-23 yrs; OM in microaggregates, 3-80 yrs; OM in silt+clay, 5-1000. LF (light fraction) is a transitory pool of OM between fresh residues and humified SOM. | |
| 1520 | Carter, M.R. | A review of conservation tillage strategies for humid temperate regions | 1994 | Tillage | Journal | Soil Tillage Res.; 31 (4); 289-301 | English | Hardcopy:Partial | n/a | Appropriate conservation tillage practices for such regions may make judicious use of cultivation to address soil and climatic constraints, and use tillage for straw incorporation .. |
| 510 | Carter, M.R., Angers, D.A., Gregorich, E.G. & Bolinder, M.A. | Organic carbon and nitrogen stocks and storage profiles in cool humid soils of Eastern Canada | 1997 | Soil Organic Carbon | Journal | Can. J. Soil Sci.; 77 (2); 205-210 | English | Hardcopy:Full | Study of soils from 16 sites to determine the size and soil profile distribution of their OM stocks. The SOC content varied from 0.5 to 2.2% and the C/N ratio from 8.3 to 13.8 [with one anomalous figure of 17.1 from a site - a silty loam humic Gleysol under continuous silage maize]. | |
| 511 | Carter, M.R., Angers, D.A., Gregorich, E.G. & Bolinder, M.A. | Characterising organic matter retention for surface soils in Eastern Canada using density and particle-size fractions | 2003 | Soil Organic Carbon | Journal | Can. J. Soil Sci.; 83 (1); 11-23 | English | Hardcopy:Partial | Study of soils from existing short- to long-term agricultural expt.s to determine the quantity and distribution of SOM | .. grass and forest soils, which contain relatively high concentrations of OM, generally gave more POM than arable soils. .. the clay- plus silt-sized OM can be considered as an inherent measure of the capacity of any one soil to store OM, while the POM fraction is a dynamic pool closely affected by soil management and recent C inputs.; .. OM exists as a continuum in soil from strongly stabilised to non-protected forms. .. although the POM is considered labile, its rate of decomposition would be dependant on the chemical characteristics of the organic inputs.; Macroaggregates (> 250 m diam.) formed by root-microbe-OM and mineral particle interactions, contain C in various fractions such as POM, LF, microbial biomass and microaggregates. Only C in the latter can be considered to be protected, as the other fractions are relatively labile.; The POM constituted about 20% of the total SOC, while LF was generally below 7%. .. about 60% of organic C was stored in WSA [water-stable aggregates]. |
| 1521 | Carter, M.R., Gregorich, E.G., Angers, D.A., Donald, R.G. & Bolinder, M.A. | Organic C and N storage and organic C fractions in adjacent cultivated and forested soils of eastern Canada | 1998 | Soil Organic Carbon; Tillage | Journal | Soil Tillage Res.; 47 (3-4); 253-261 | English | Hardcopy:Partial; Wordperfect:Full | Study to compare the organic C and N in varied soils from adjacent forested and cultivated sites. Cultivation decreased the mass of organic C (35%) and total N (10%) in some soils, but increased them (by 25% and 37%) in others. | In general losses of SOM in eastern Canada due to a shift of land use from forest to arable agriculture were less than values reported for prairie soils. The shift from forest to agriculture, however, had a marked effect on soil light fraction C and microbial biomass C, but less influence on macro-organic C. In some cases use of forages restored or increased the level of SOM and organic C fractions. |
| 1522 | Catt, J.A., Howse, K.R., Christian, D.G., Lane, P.W., Harris, G.L. & Goss, M.J. | Assessment of tillage strategies to decrease nitrate leaching in the Brimstone Farm Experiment., Oxfordshire, UK | 2000 | Mineralisation; Soil N Dynamics; Tillage | Journal | Soil Tillage Res.; 53; 185-200 | English | Hardcopy:Partial; Wordperfect:Full | Half the plots were direct-drilled with minimum tillage & half were ploughed. In the first two years the ploughed plots showed greater nitrate concentrations in both the drains & the run-off. When the minimum tillage plots were ploughed, the nitrate conc'n in the drainage water increased till it slightly exceeded that in the continuously ploughed plots. This indicates that N that had been stored in the soil of the minimum-tillage plots was being mineralised. | .. mineralis'n of SOM is a rather irregular process, largely but not entirely dependent on soil moisture, & can be delayed for several yrs by dry conditions. |
| 1523 | Causarano, H. [abstract only] | Factors affecting the tensile strength of soil aggregates | 1993 | Soil (General) | Journal | Soil Tillage Res.; 28 (1); 15-25 | English | Hardcopy:Partial | The dependence of soil tensile strength on water content, OM content, aggregate size and the interaction of these factors was studied. | .. tensile strength depended mainly on water content.; For the clay soil .. a large OM content appeared to strengthen wet soil aggregates and weaken dry ones.; The tensile strength of the smallest aggregates was about 50% higher than the biggest ones. |
| 592 | Cavazzoni, J., &Volk, T. | Assessing long-term impacts of increased crop productivity on atmospheric CO2 | 1996 | Greenhouse Gases; Sustainability | Journal | Energ. Policy; 24 (5); 403-411 | English | Hardcopy:Full | Increased crop productivity alleviates CO2 release to the atmosphere | Cereal production has increased approximately threefold in the last forty years or so .. perhaps 90% of increased cereal production from 1950 to the present is attributable to increased yields..; After accounting for .. the C released into the atmosphere via fossil fuel energy inputs for crop production, the assessment here indicates that increased crop productivity will alleviate CO2 release to the atmosphere primarily by preventing additional land cultivation.; From a global perspective the present C debt of approximately 160 Pg C due to land cultivation would have been .. 260 Pg C or more, were it not for the higher cereal yields brought about by increasing fossil fuel inputs since 1950.; .. the effective C sink of 6 Mg per hectare per year for cropland converted to energy crops because of yield increases corresponds to about 240 GJ per hectare per year, which would provide renewable primary energy for roughly 20 hectares of cereal land at 13 GJ per hectare per year (the average 1982 commercial energy input for cereal production in industrialised regions). This implies that the average energy needs of increased crop productivity would be generally supplied if productivity increases are such as to allow about 5% of cropland to be freed and converted to energy crops (neglecting crop residue bio-energy utilisation). |
| 567 | Cavigelli, M. & Robertson, G.P. | The functional significance of denitrifier community composition in a terrestrial ecosystem | 2000 | Soil Microorganisms; Soil N Dynamics | Journal | Ecology; 81 (5); 1402-1414 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to test whether differences in the denitrifier microbial community compos'n in soil from two different fields (one conventionally tilled arable & @the other never tilled) affected the rates of denitrification & N2O production. Compared with the successional field, in the arable field the enzymes involved in N2O production were more inhibited by O2 & less sensistive to pH & there were relatively less active nitrous oxide reductase enzymes, which reduce N2O to N2. | .. native microbial community composition regulates an important ecosystem (function in these soils.; .. the shape of the rN2O [rate of N2O production] curve with increasing oxygen was different for each denitrifying community. |
| 778 | Chadwick, D.R., John, F., Pain, B.F., Chambers, B.J. & Williams, J. | Plant uptake of nitrogen from the organic nitrogen fraction of animal manures: a lab. expt. | 2000 | Mineralisation; Stockless Farming; Soil N Dynamics | Journal | J. Agr. Sci.; 134; 159-168 | English | Hardcopy:Partial | Lab. study of the mineralisation of organic N in various animal manures, the C/N ratio of which ranged from 3.7 for poultry manure to 14.8 for cattle manure. | @; .. organic materials with C/Norg ratios of 15 or more will initially immobilise N, whilst C/Norg ratios of <15 will result in mineralisation and the lower the C/N ratio the greater the mineralisation rate.; N mineralisation was generally greatest from |
| 1411 | Chan, K.Y. & Heenan, D.P. | Lime-induced loss of soil organic carbon and effect on aggregate stability | 1999 | Soil Organic Carbon | Journal | Soil Sci. Soc. Am. J.; 63 (6); 1841-1844 | English | Hardcopy:Partial; Wordperfect:Full | Field expt. to study the effect of liming on the protection of SOM | Three years after lime application at a rate of 1.5 t ha-1, increases in water stability of macroaggregates were observed despite significant losses in OC in the limed soils.; OC lost as a result of liming was mainly (up to 84% of total loss) in the form of light fraction (specific gravity <1.8) bound to macroaggregates. ... a given level of aggregate stability was achieved at a lower SOC level in limed soil (e.g. total C level for a 50% aggregate stability was 13.0 `and 17.8 g kg-1 for limed and unlimed soils respectively). |
| 1524 | Chan, K.Y., Heenan, D.P. & Oates, A. | Soil carbon fractions and relationship to soil quality under different tillage and stubble management | 2002 | Soil Organic Carbon; Tillage | Journal | Soil Tillage Res.; 63 (3-4); 133-139 | English | Hardcopy:Partial | 12-year expt. to determine the effect of different tillage and residuemanagement treatments on the soil C fractions | .. the largest differences [between the treatments] existed in the top 0.05m [of the soil], where a difference of 8.0 g/kg (equivalent to 5.2 t ha-1) was found between the extreme treatments (direct drilled/stubble retained .. and conventional cultivation/stubble burnt ..). Tillage had a much greater effect in reducing total C than stubble burning, accounting for 80% of the total difference between the extreme treatments in 0-0.05 m layer .. with tillage preferentially reducing the particulate organic C (POC) (>53 m) (both free and associated POCs) ..; Furthermore, tillage was related to the decline in mineralisable nitrogen (MN) due to the loss of POC, especially the free POC fraction. POC was a more sensitive indicator of soil quality changes under different tillage and stubble management than TOC. |
| 1106 | Chancellor, W.J. & Goss, J.R. | Balancing energy and food production, 1975-2000 | 1976 | Energy in Agriculture | Journal | Science; 192 (4236); 213-217 | English | Hardcopy:Partial | Review of current energy use in agriculture and predictions of future trends, including a table of world land use and annual potential photosynthetic product. xThe world annual insolation is said to be 1682 x 107 kcal/ha. | |
| 1196 | Chantigny, M.H., Angers, D.A., & Rochette, P. | Fate of carbon and nitrogen from animal manure and crop residues in wet and cold soils | 2002 | Soil Organic Carbon; Stockless Farming; Soil N Dynamics | Journal | Soil Biol. Biochem.; 34 (4); 509-517 | English | Hardcopy:Full; PDF:Full | Expt. to study C & N dynamics in soils during winter after various organic amendments | @; The level of O2 consumption rates in amended soils was in decreasing order pig slurry=alfalfa > cattle manure=maize. Average O2 consumption rates were not significantly correlated to the total organic C, total N, lignin content or C/N ratio of the amen |
| 1412 | Chantigny, M.H., Angers, D.A., Prévost, D., Vézina, L.P. & Chalifour, F.P. | Soil aggregation and fungal and bacterial biomass under annual and perennial cropping systems | 1997 | Soil Microorganisms; Soil (General) | Journal | Soil Sci. Soc. Am. J.; 61; 262-267 | English | Hardcopy:Full | Field expt. over three growing seasons to study the effect of different crops on soil aggregation and soil microbial biomass | .. the MWD of water-stable aggregates was higher under reed canary grass .. and timothy than under broad beans or wheat. Intermediate values were found under alfalfa & brome grass.; Close correlations were found between MWD & both fungal glucosamine & bacterial muramic acid.; .. the close relationship with fungal glucosamine suggests that fungi played a dominant role in soil macroaggregation |
| 895 | Chapin, F.S. | New cog in the nitrogen cycle | 1995 | Mineralisation; Soil N Dynamics | Journal | Nature (Lond.); 377; 199-200 | English | Hardcopy:Partial; PDF:Full | Review of recent research on the uptake of organic N compounds by a pine spp., which suggests that, while the mineralisation of organic N is the rate-limiting step in fertile ecosystems, in infertile systems plants also use DON and that the polyphenols such as tannin, which occur in high concentrations in plants on infertile soils and are exuded from the plant roots, may bind the DON so as to enhance the supply of organic N to the plant and give them a competitive edge over plants that prefer to use ammonium or nitrate as their N source. | `; Arctic plants readily absorb amino acids4 and grow more rapidly on organic than on inorganic sources of nitrogen. In addition, ectomycorrhizal and ericoid mycorrhizal fungi, which are common in infertile soils, directly break down proteins in SOM, absorbing and transferring the resulting amino acids to their host plants without nitrogen being mineralised to inorganic form. |
| 896 | Chapin, F.S. & Ruess, R.W. | The roots of the matter | 2001 | Plant C&N Allocation; Soil Organic Carbon | Journal | Nature (Lond.); 411; 749-752 | English | Hardcopy:Full; PDF:Full | Review of recent research into soil respiration and the proportion of it that is derived from roots and their associated symbiotic mycorrhizae | Photosynthesis by terrestrial vegetation accounts for about half of the C that annually cycles between Earth and the atmosphere. Although above-ground plant production is relatively well documented .., the quantity of C that plants transfer below ground is not well known. ... large components of belowground plant production, such as exudation of org. compounds by roots and transfer of carbohydrates to associated mycorrhizal fungi, are difficult to study non-destructively and have not been estimated. Estimates of the contribution of root respiration to total CO2 efflux from soil range from 10% to 90%, with methodological uncertainties accounting for most of this variation.; ... relative to temperate forests, boreal vegetation allocates a higher proportion of fixed C to belowH ground structures7. ... at least half of the soil respiration in these systems is derived from roots and mycorrhizae.; The ratio of plant-associated respiration derived from roots to that from their symbiotic mycorrhizae remains a mystery.; .. root respiration increases exponentially with increases in soil temp. |
| 593 | Chapman, P.F. | The energy costs of materials | 1975 | Energy in Agriculture | Journal | Energ. Policy; ; | English | Hardcopy:Partial | The need to know the energy required to produce materials and the conventions adopted to calculate it | .. the energy conversion efficiency for generating electricity is 23.85% |
| 3 | Chardon, W.J. | The role of the soil in phosphorus cycling | 2000 | Phosphorus Cycling | Book | Weidema, B.P. & Meeusen, M.J.G. (eds.); Agricultural data for Life Cycle Assessments, Vol 2, Agric. Econ. Res. Inst.; | English | Hardcopy:Partial; Wordperfect:Full | Review of current knowledge on how phosphorus cycles in the soil | On a world scale a net transport of P to the oceans occurs, maintained by weathering of minerals and by erosion. .. In general, more P has to be added than is taken off by the crop to compensate for P becoming less available for plant uptake. In regions with a surplus of animal manure, P contents of the soil can become very high, creating problems due to eutrophication of surface waters.; When organic fertilisers (e.g. compost, animal manure and sewage sludge) are applied, mineralisation has to take place before plants can take up P.; After application of inorganic P fertilisers to a soil, or when P has been released from organic fertilisers by mineralisation, several reactions with the soil can take place: adsorption ..; absorption ..; immobilisation ..; and precipitation .. Adsorption of P mainly occurs onto hydroxides of iron or aluminium. |
| 611 | Chaves, B., Neve, S. de, Hofman, G., Boeckx, P. & Cleemput, O. van | Nitrogen mineralisation of vegetable root residues and green manures as related to their (bio)chemical composition | 2004 | Green Manure; Mineralisation; Soil N Dynamics | Journal | Eur. J. Agron.; 21; 161-170 | English | Hardcopy:Partial; PDF:Full | 4-month lab. expt. to study the N dynamics of vegetable root decomposition | All fine roots, except these of Brussel sprouts, showed a net N release throughout the incubation. All large roots showed a slight N immobilisation at the start of the incubation, but at the end of the incubation a small net N release was observed, except for Brussel sprouts. The roots of Brussel sprouts immobilised N throughout the entire incubation. The leaves of the green manures released more N than both stems (only for white mustard) and roots.; The large roots of cabbages released maximum 13% of their N and the N released from fine roots was between 20 and 25% of total N. The overall N mineralisation (large + fine roots) of the cabbages was on average 15% of total N, which was lower than for the roots of other annual plants, like the leek roots (50% of total N) and the green manures roots (16 and 28% of total N). |
| 1481 | Chaves, B., Neve, S. de, Piulats, L.M., Boeckx, P., Cleemput, O. van & Hofman,G. | Manipulating the N release from N-rich crop residues by using organic wastes on soils with different textures | 2007 | Soil N Dynamics | Journal | Soil Use Manag.; 23; 212-219 | English | Hardcopy:Full; PDF:Full | Field expt. to study the effect of compost, sawdust and straw on the N mineralisation of vegetable residues and the effect of malting sludge and vinasses on the re-mineralisation of the N in spring | .. incorporation of green waste compost and sawdust did not significantly increase microbial biomass N and did not lead to a significant N immobilisation of crop residue-N. .. straw did increase microbial biomass N and showed a good N immobilisation potential... During spring, there was no consistent remineralisation of immobilised N after the addition of malting sludge or vinasses... |
| 702 | Chen, R.S. & Kates, R.W. | World food security: prospects and trends | 1994 | Miscellaneous; Sustainability | Journal | Food Policy; 19 (2); 192-208 | English | Hardcopy:Partial | Review of the possibilities of feeding the world's human population in the 21st century | In 1990 we estimate that 15-35 million people were at risk of famine, 786 million were vulnerable to chronic undernutrition and hundreds of millions suffered from micronutrient deficiencies .. and other nutritional impairments.; A normative scenario to achieve food security in the .. world of 2060 requires widespread acknowledgement of food as a human right, large increases in food production and income, a pervasive global safety net and the capacity to cope with surprise.; Speculative and clearly optimistic, our .. scenario offers multiple pathways for achieving a food-secure world. |
| 7 | Chen, Y., Chefetz, B. & Hadar, Y. | Formation and properties of humic substance originating from composts | 1996 | Compost & Biocontrol | Book | Bertoldi, M. de, Sequi, P., Lemmes, B., & Papi, T. (eds.); The science of composting; | English | Hardcopy:Partial; Wordperfect:Full | Review of exptal work to study the formation and properties of humic substances in composts | Humic substances constitute a large fraction of the OM in compost and they are its most active fraction, due to their effects on soil ecology, structure, fertility and metal complexes and on plant growth.; .. HA extracted from mature compost exhibits more aromatic structures and carboxyl groups and less carbohydrate components than that from immature compost. .. In soils the addition of composts was found to stimulate growth beyond that provided by mineral nutrients, presumably because of the effects of HS. |
| 1605 | Chen, Y., Tessier, S. & Rouffignat, J. | Soil bulk density estimation for tillage systems and soil textures | 1998 | Soil (General) | Journal | Trans. ASAE (Am. Soc. Agric. Eng.); 41 (6); 1601-1610 | English | Hardcopy:Partial | Modelling the bulk density of soil on the basis of 60 previously published studies. Clay content and OM content are major determinants of soil bulk density. Tillage modifies BD in different ways, depending on tillage type, depth, secondary tillage, soil texture and OM content. | |
| 1609 | Cheng, W. | Rhizosphere feedbacks in elevated CO2 | 1999 | Priming Effect; Soil Microorganisms | Journal | Tree Physiol.; 19; 313-320 | English | Hardcopy:Full; Wordperfect:Full | Modelling the link between the increased rhizosphere input in response to elevated CO2 and the rate of SOM decomposition | Depending on specific plant and soil conditions, the increased C input to the rhizosphere can result in an increase, a decrease or no effect on SOM decomposition and nutrient mineralisation. Three mechanisms may account for these inconsistent results: (1) the preferential-substrate-utilisation hypothesis; (2) the priming-effect hypothesis; & (3) the competition hypothesis i.e. competition for mineral nutrients between plants and soil microorganisms.; If the increased (rhizosphere substrate input in response to elevated CO2 reduces microbial utilisation of original SOM.., a negative feedback exists as the substrate-preference hypothesis states, so that SOM decompos'n decreases.If the increased rhizosphere input .. results in an increase in overall microbial biomass turnover rate.., a positive feedback exists as the priming hypothesis states, so that SOM decomposition increases. Under highly .. nutrient-limited conditions the increased rhizosphere input in response to elevated CO2 may intensify the competition for .. nutrients between roots & microorganisms and result in a decrease in C substrate usage, a reduced substrate utilisation efficiency .. and a lower amount of microbial biomass. This pattern fits the competition hypothesis well. |
| 1413 | Cheng, W., Johnson, D.W. & Fu, S. | Rhizosphere effects on decomposition: controls of plant species, phenology and fertilisation | 2003 | Priming Effect; Roots & Rhizodeposition | Journal | Soil Sci. Soc. Am. J.; 67; 1418-1427 | English | Hardcopy:Partial; PDF:Full | Expt. to study the priming effect of plant roots on SOM decompos'n by comparing the rate of C loss from soil with wheat, soya bean and no plant growing in it. | @; .. rhizosphere respiration may range from 30 to 80% of total belowground CO2 efflux.; The rhizosphere priming effect was responsible for a major portion of the total soil C efflux.; Different plant species produce rhizosphere priming of different magni |
| 1197 | Cheng, W., Zhang, Q., Coleman, D.C., Carroll, C.R. & Hoffman, C.A. | Is available carbon limiting microbial respiration in the rhizosphere? | 1996 | Soil Microorganisms | Journal | Soil Biol. Biochem.; 28 (10/11); 1283-1288 | English | Hardcopy:Partial; PDF:Full | Field/lab. expt. to study the effect of plant roots on microbial respiration. There was a threshold of available C saturation in the rhizosphere, equal to about 0.1 mg water-soluble C/g soil, above which microbial respiration was not limited by available C. | .. carbon availability in the rhizosphere is much higher than in the bulk soil.; .. we employed the concept of C availability index (CAI: the ratio of basal respiration to substrate-induced respiration).; The CAI values of the rhizoplane and the rhizosphere soils in the field maize experiment were close to 1, indicating that available C was not a limiting factor for microbial respiration ..; .. the conversion of plant C into microbial biomass in the rhizosphere is very low, i.e. 13%. The mineral nutrient supply in the rhizosphere may severely limit microbial growth and activities. |
| 633 | Chenu, C., & Plante, A.F. | Clay-sized organo-mineral complexes in a cultivation chronosequence: revisiting the concept of the 'primary organo-mineral complex' | 2006 | Soil Organic Carbon | Journal | Eur. J. Soil Sci.; 57; 596-607 | English | Hardcopy:Partial; PDF:Full | Field expt. to test whether Christensen (1996)'s primary organo-mineral complexes, characterised as the primary structure of soils as defined by soil texture, really did consist of primary particles | .. many of the so-called <2-m particles were in fact nanometre- to micrometresized microaggregates, in which OM was encrusted by minerals .. We conclude that true primary organo-mineral complexes do not correspond to reality & must be regarded as conceptual entities. |
| 133 | Chenu, C., Arias, M. & Besnard, E. | The influence of cultivation on the composition and properties of clay-organic matter associations in soils | 2001 | Soil Organic Carbon; Tillage | Book | Rees, R.M., Ball, B.C., Campbell, C.D. & Watson, C.A. (eds.); Sustainable Management of Soil Organic Matter; | English | Hardcopy:Partial; Wordperfect:Full | Field expt. to assess the effect of cultivation on the OM present in the <2 m particle size fraction | Cultivation decreases SOM stocks, in particular labile fractions, such as POM. OM in the <2 m fraction of soils is less depleted by cultivation. This is ascribed to the slow turnover rate of <2 m SOM, due to its chemical nature and presumably also to its protection from decomposition by the clay minerals. |
| 1691 | Chervonyj, A. | Research project on RCW technology on rye (Secale cereale) for 1997-98 | 1999 | Lignin and CBW | Website | www.sbf.ulaval.ca/brf | English | Hardcopy:Partial | Two-year field expt. to test the effect of chipped branch wood on the soil and on a crop of rye. Wood from various broad-leaved tree species was used. On some plots forest litter [or topsoil ?] was also added. The rye yields varied with species of wood applied in the order Carpinus [hornbeam ?] > sycamore > false acacia > oak > lime > alder > hazel > aspen > birch > willow. In a poor soil the last four species actually reduced the rye yield compared with the untreated control. As for humus and organic C content, goat willow and aspen gave the best results. Hazel and lime also did well. Oak was the worst, followed by sycamore. | Under the RCW influence chemical and physical characteristics of the soil have improved significantly .. Thus, the content of humus, OM, hydrolysed [available] N, moveable phosphorus, exchangeable calcium, magnesium etc. in the soil has increased considerably. |
| 634 | Cheshire, M.V., Bedrock, C.N., Williams, B.L., Chapman, S.J., Solntseva, I. & Thomsen, I.K. | The immobilisation of nitrogen by straw decomposing in soil | 1999 | Soil N Dynamics | Journal | Eur. J. Soil Sci.; 50; 329-341 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the immobilisation of N during straw decomposition | The total N content of the straw increased as long as the soil was not too wet, such that there was overall immobilisation.; ... N immobilisation is mainly a biotic process in which fungal activity plays a much greater role than bacterial biomass.; ... fungal biomass was much greater than that of bacteria.; ... immobilisation of N is primarily caused by fungi as they decompose the straw. |
| 15 | Chesson, A. | Plant degradation by ruminants: parallels with litter decomposition in soils | 1997 | Lignin and CBW | Book | Cadisch, G. & Giller, K.E. (eds.); Driven by Nature: Plant Litter Quality and Decomposition. C.A.B. International; | English | Hardcopy:Partial; Wordperfect:Full | Review of substances making up plant cell walls and their degradation in the stomachs of ruminants and in the soil | |
| 1525 | Chivenge, P.P., Murwira, H.K., Giller, K.E., Mapfumo, P. & Six, J. | Long-term impact of reduced tillage and residue management on soil carbon stabilization: implications for conservation agriculture on contrasting soils | 2007 | Soil Organic Carbon; Tillage | Journal | Soil Tillage Res.; 94; 328-337 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the effects of different methods of tillage and residue management on SOM | In clay soils organic C accumulation, primarily within the fine sand fraction, can be enhanced by reducing disturbance due to tillage. In contrast, SOC build- up in sandy soils is hardly affected by reduced tillage practices and can only be accomplished by manipulating the coarse SOM fractions through additions of organic inputs. |
| 796 | Chon, S.-U. & Kim, J.-D. | Biological activity and quantification of suspected allelochemicals from alfalfa plant parts | 2002 | Allelopathy; Green Manure | Journal | J. Agron. Crop Sci.; 188; 281-285 | English | Hardcopy:Partial | Expt. to study the autotoxic effect of different parts of the lucerne plant | To escape the problems of autotoxicity the common field recommendation is to delay seeding of alfalfa after alfalfa for at least 2 weeks and in some cases up to 2 years.; .. leaves, stems, roots and seeds of alfalfa 'Vernal' were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. .. Among nine phenolic compounds assayed for phytotoxicity on root growth of alfalfa, coumarin, trans-cinnamic acid and o-coumaric acid .. were the most inhibitory. |
| 1198 | Chotte, J.L., Ladd, J.N. & Amato, M. | Sites of microbial assimilation and turnover of soluble and particulate 14C- labelled substrates decomposing in a clay soil | 1998 | Priming Effect; Soil Organic Carbon; Soil Microorganisms | Journal | Soil Biol. Biochem.; 30 (2); 205-218 | English | PDF:Full | Incubation of soluble (glucose, starch) and particulate (plant residue) organic substrates in soil to test the importance of substrate-soil-matrix relationships in the processes of SOM decomposition and the location of microorganisms. A priming effect was observed mainly in the first 3 days, when large amounts of indigenous biomass C disappeared from the soluble-amended soil, being replaced by substrate biomass C and thus leaving total amount of biomass C unchanged. In the residue-amended soil the particulate OM offered new sites for microorganisms, so the total biomass C increased. | There was little or no turnover of 14C apparent within the first 3 d, as indicated by high (0.60) [= 60%] growth efficiencies.; .. biomass 14C located in the light fraction (Lf >250 mm) had disappeared by 66 d.; True priming effects, H the stimulation of the decomposition of non-biomass 12C compounds, may result in part from the accelerated death of biomass 12C.; .. although the origins of this extra C mineralised from soil organic pools have not yet been evaluated ... evidence suggests that this primed C is derived from the turnover of dead cells by secondary populations.; .. a soil has a given capacity to protect microorganisms. Above this threshold biomass C within the soil matrix is rapidly preyed upon.; .. one should .. split the biomass compartment .. into two different pools, one associated with fresh POM, the other stabilised within existing microaggregates, these compartments having different residence time. |
| 206 | Choudhary, M.A., Akramkhanov, A. & Saggar, S. | Nitrous oxide emissions from a New Zealand cropped soil: tillage effects, spatial and seasonal variability | 2002 | Greenhouse Gases; Soil N Dynamics; Tillage | Journal | Agric. Ecosyst. Environ.; 93 (1); 33-43 | English | Hardcopy:Partial | Expt. to compare the N2O emissions from plots under conventional tillage, zero tillage and sheep-grazed permanent pasture. there was no significant difference @in N2O emission rate between the zero tillage and the conventional tillage, but that from the permanent pasture was significantly lower. | The N2O emissions measured from this occasionally sheep-grazed permanent pasture were one half of those reported for intensively grazed by dairy stock.; The `strong correlation between N2O emissions and soil water content in all treatments suggests that the high rainfall and .. drainage characteristics are important in the assessment of N2O fluxes from those fields. |
| 50 | Christen, O. | No more definitions please! Some reflections about the ideas and principles of sustainable agriculture | 1998 | Sustainability | Book | El Bassam, N., Behl, R.K. & Prochnow, B. (eds.); Sustainable Agriculture for Food, Energy and Industry, vol.1; 48-52 | English | Hardcopy:Full | Sustainable agriculture should be dealt with in a framework of research priorities, instead of focusing on definitions. | Since research into sustainable agricultural systems with very slow but extremely important processes like e.g. decline or improvement of soil fertility, changes in vegetation etc. the research should be long term.; .. the organisation of research has to be changed from a top-down to a ;more farmer orientated approach. |
| 635 | Christensen, B.T. | Physical fractionation of soil and structural and functional complexity in organic matter turnover | 2001 | Soil Organic Carbon; Soil (General) | Journal | Eur. J. Soil Sci.; 52 (3); 345-353 | English | Hardcopy:Full; PDF:Full | Review of soil research based on the physical fractionation of the soil into three parts: clay-, silt- and sand-sized primary mineral-associated OM, secondary (micro- and macro-) aggregations of the primary particles and, thirdly, the structurally intact soil | .. OM .. provides a reservoir of energy and nutrients in the soil that buffers ecosystems against perturbations.; Uncomplexed [i.e. non-mineral associated] OM consist mainly of particulate partly decomposed plant .. residues, but can also encompass fungal hyphae, spores, faecal pellets,.. root fragments .. [It] is neither a readily available nor a major source of mineral N .. it can be a source of readily available C and energy to the decomposers.; Small microaggregates (<20m) contain little if any occluded OM and the main agents in the stabilisation .. are microbial products, root exudates, polyvalent cations and other persistent binding agents.; A continuous input of plant litter .. may be crucial for the formation of macroaggregates. |
| 1526 | Christian, D.G. & Bacon, E.T.G. | A long-term comparison of ploughing, tine cultivation and direct drilling on the growth and yield of winter cereals and oilseed rape on clayey and silty soils | 1990 | Tillage | Journal | Soil Tillage Res.; 18 (4); 311-331 | English | Hardcopy:Partial | 10-year field expt. to study the effects of tillage methods on the growth and yield of crops. On average yields were only depressed by 2% by zero tillage and, in some cases, were up to 7% higher than with ploughing. | .. differences in yield between cultivation treatments were small and inconsistent. Oilseed rape yielded significantly more after direct drilling than ploughing because of better establishment and uniformity of growth. The success of continuous reduced tillage depended on both burning crop residues and good weed control.; The expt.s were conducted .. burning straw residues. .. When straw cannot be burnt, direct drilling and shallow tillage systems have proved to be unsuitable on a medium clay soil.; Reduced tillage systems .. are unlikely to be more widely adopted by farmers in the U.K. their future lies in parts of the world where soil and water conservation are of greater importance .. |
| 1527 | Christian, D.G. & Miller, D.P. | Straw incorporation by different tillage systems and the effect on growth and yield of winter oats | 1986 | Tillage | Journal | Soil Tillage Res.; 8; 239-252 | English | Hardcopy:Partial | Field expt. to compare the effectiveness of different tillage systems to incorporate straw residues | On both chopped straw and stubble establishment of winter oats was best after straw incorporation by tine cultivation, followed by ploughing and worst after direct drilling. Plough based systems produced the highest plant dry weights. |
| 773 | Christian, D.G., Bacon, E.T.G., Brockie, D., Glen, D., Gutteridge, R.J. & Jenkyn, J.F. | Interactions of straw disposal methods and direct drilling or cultivation on winter wheat grown on a clay soil | 1999 | Tillage | Journal | J. Agr. Eng. Res.; 73; 297-309 | English | Hardcopy:Partial | The results are presented of a nine-year expt. in continuous winter wheat production to compare the wheat yields after zero tillage or after ploughing to 5, 15 or 25 cm. The straw from the previous crop is either burnt, chopped and spread or baled and led away. Irrespective of tillage method, straw burning always gave the greatest yield. The yields were reduced by the following amounts if other methods of dealing with the straw were used: chopping and spreading - 33%, 5 cm. deep incorporation - 20%, 15 cm. incorporation - 1%, 25 cm. incorporation - 9%. | .. sowing cereals after shallow cultivations or by direct drilling in the presence of straw residues is unreliable and may restrict both early crop growth and yield. .. Ploughing at least to 15 cm. depth is recommended in order to improve reliability in crop establishment .. and to help maintain crop yield .. |
| 283 | Chung, I.M. & Miller, D.A. | Effect of alfalfa plant and soil extracts on germination and growth of alfalfa | 1995 | Allelopathy; Green Manure | Journal | Agron. J.; 87 (4); 762-767 | English | Hardcopy:Partial | Lab. expt. to test the effect of aqueous extracts of different parts of lucerne plants on the germination and seedling growth of lucerne | .. all aqueous extracts significantly reduced seed germination .. Flower extracts were the most inhibitory at all concentrations, while the extract of the mixture of all plant parts was the least inhibitory. .. Seed extract reduced germination to 39% .. the flower extract caused the greatest reduction in hypocotyl length (28%) when compared with other part extracts. |
| 284 | Chung, I.M. & Miller, D.A. | Allelopathic influence of nine forage grass extracts on germination and seedling growth of alfalfa | 1995 | Allelopathy; Green Manure | Journal | Agron. J.; 87 (4); 676-772 | English | Hardcopy:Partial | Lab. expt. to determine the allelopathic effect of nine forage grasses on lucerne | Alfalfa [lucerne] germination ranged from 64% for tall fescue extracts to 91% for the control. .. Timothy extracts caused the lowest survival percentage [of lucerne seedlings] of 59%, compared to the control of 88%. |
| 285 | Chung, I.M. & Miller, D.A. | Natural herbicide potential of alfalfa residue on selected weed species | 1995 | Allelopathy; Green Manure | Journal | Agron. J.; 87 (5); 920-925 | English | Hardcopy:Full | Lab. expt. to demonstrate the inhibiting effect of an aqueous extract of lucerne on the germination and establishment of various weeds. There was 44% inhibition of germination in the case of fat hen. | |
| 314 | Churchill, D.B., Horwath, W.R., Elliott, L.F. & Bilsland, D.M. | Low - input, on - farm composting of high C:N ratio residues | 1996 | Compost & Biocontrol; Stockless Farming | Journal | Am. J. Alternative Agr.; 11 (1); 7-9 | English | Hardcopy:Partial | Composting ryegrass on the field in windrows which are turned several times. | .. compost perennial ryegrass straw on-farm by forming windrows and turning them either zero, two, four or six times throughout the year with a commercial straddle-type turner. No water beyond normal rainfall and no N other than that contained in the straw was added. The volume of straw was reduced by up to 88% with four or six turns over 20 to 24 weeks. The average internal temperature of the straw windrows reached a maximum of 54$C. with four turns. |
| 1528 | Clapp, C.E., Allmaras, R.R., Layese, M.F., Linden, D.R. & Dowdy, R.H. | Soil organic carbon and 13C abundance as related to tillage, crop residue & N fertilisation under continuous corn management | 2000 | Soil Organic Carbon; Tillage | Journal | Soil Tillage Res.; 55 (3-4); 127-142 | English | Hardcopy:Partial | 13-year expt. to study the effect of tillage and crop residue input on SOM under continuous maize. With annual tillage the SOM declined slightly, with or without @crop residue input. It remained unchanged at 55 Mg ha-1 with zero tillage and no residue input, but increased by about 14% with zero tillage and residue input combined. The corresponding proportions of maize-derived C in the SOM after 13 years were 0.1, 0.05 and 0.15 respectively for the three treatments. These proportions were not affected by the application of N fertiliser. | The half-life for decomposition of the original or relic SOC was longer when stover was returned, shortened when stover was harvested and N applied and sharply lengthened when stover was not harvested and N was partially mixed with the stover. Separating SOC storage into relic and current crop sources has significantly improved our understanding of the main and interacting effects of tillage, crop residue, and N fertilisation for managing SOC accumulation in soil. |
| 321 | Clar, U., Becker, K. & Susenbeth, A. | A mobile mask technique for measuring gas exchange in cattle | 1993 | Greenhouse Gases | Journal | Anim. Res. Dev.; 37; 48-58 | English | Hardcopy:Full | Expt. to measure the exhalation of CO2 by cattle. 5 adult oxen with an average liveweight of 564 kg were tested at rest and pulling a load. | xThe rate of exhalation of CO2 was 2.25 and 7.38 l/min for resting and pulling animals respectively. |
| 806 | Clar, U., Becker, K., Susenbeth, A. | A mobile mask technique with gas meter for measuring gaseous exchange in cattle | 1992 | Greenhouse Gases | Journal | J. Anim. Physiol. Anim. Nutr.; 67(3); 133-142 | English | Hardcopy:Partial | Expt. to compare a mobile mask technique for measuring gas exchange in cattle with the conventional respiration chamber method. The average liveweight of the xoxen was 564 kg. The CO2 production rate was about 2.25 l/min for oxen at rest and 7.33 l/min for oxen working. | |
| 1649 | Clark, C. | The Economics of Subsistence Agriculture | 1967 | Agricultural Ecology | Book | Clark, C. & Haswell, M; The Economics of Subsistence Agriculture; | English | Hardcopy:Partial | The productivity of subsistence agriculture is examined. Data is given on yields and labour requirements in primitive agriculture | Even at these low levels of productivity there is a certain amount of trade in agricultural produce; and with a comparatively productive system of shifting agriculture, as among the Hanunoo, it becomes substantial and regular. .. some 10-15 per cent of the agricultural product is traded. |
| 286 | Clark, M.S., Horwath, W.R., Shennan, C., & Scow K.M. | Changes in soil chemical properties resulting from organic and low-input farming practices | 1998 | Cover Crops; Organic Farming; Stockless Farming | Journal | Agron. J.; 90 (5); 662-671 | English | Hardcopy:Partial; PDF:Full | 8-year study to compare an organic system depending on FYM applications and winter cover crops, a conventional system receiving synthetic fertiliser inputs and a low-input system using cover crops and animal manure during the first 3 years and cover crops and synthetic fertiliser for the remaining 5 years. | After 4 years soils in the organic and low-input systems had higher SOC, soluble P, exchangeable K and pH. Ceasing manure applications in the low-input system in Year 4 resulted in declining levels of organic C, soluble P and exchangeable K.; Differences in total N appeared to be related in part to inputs, but perhaps also to differing efficiency of the farming systems at storing excess N inputs: the low-input system appeared to be most efficient and the conventional system .. least efficient.; .. organic and low-input farming .. results in small but important increases in SOC and larger pools of stored nutrients, which are critical for long-term fertility maintenance.; .. the manure inputs were important in increasing organic C. |
| 947 | Clemens, J. & Ahlgrimm, H.J. | Greenhouse gases from animal husbandry: mitigation options | 2001 | Greenhouse Gases | Journal | Nutr. Cycl. Agroecosyst.; 60; 287-300 | English | Hardcopy:Partial | Review of sources of greenhouse gas emissions in animal farming and their mitigation. CO2 is emitted as a result of animal metabolism and of microbial action during storage and field application of manure, but is not considered in detail in this review. | |
| 155 | Clements, R.O. & Asteraki, E.J. | Development of a low-input bi-cropping system for growing cereals in an understorey of white clover | 1993 | Clover Sward | Book | ; White clover in Europe: state of the art, REUR Technical Series 29, FAO; | English | Hardcopy:Partial; Wordperfect:Full | Review of research on the feasibilty of growing cereals in a clover sward | .. winter wheat and spring barley appeared to be the most compatible for maintaining the clover sward. However spring barley may require agrochemical suppression of the clover for good establishment.; Pest and disease problems to date using the clover understorey system have been much reduced, although the reasons for this are not clear. |
| 688 | Clements, R.O. & Donaldson, G. | Clover and cereals - low-input bi-cropping | 1997 | Clover Sward; Stockless Farming | Journal | Farm. Conserv.; 3 (4); 12-14 | English | Hardcopy:Full | Field trials on the growing of cereals through a permanent sward of white clover. The cereal yields from bi-cropping were only 50-60% of those from conventional cropping. Advantages are: reduced pests and diseases (partly because of reduced rain splash), less weed, more earthworms, reduced soil erosion. | Initially a sward of pure white clover is established in the spring (sown alone or undersown in a spring-sown barley silage whole crop) and in the autumn (mid to late September) the clover is defoliated either by machine and ensiled or grazed by sheep. .. The cereal is then direct drilled into the clover. .. In spring .. a small amount of N is needed (around 50 kg N/ha ..) .. |
| 423 | Cleveland, C., Nemergut, D., Schmidt, S. & Townsend, A. | Increases in soil respiration following labile carbon additions linked to rapid shifts in soil microbial community composition | 2007 | Soil Microorganisms | Journal | Biogeochemistry (Dordr.); 82 (3); 229-240 | English | Hardcopy:Partial | Lab. expt. to study the effect of adding DOM to soil on the soil's microbial community composition | @; .. additions of DOM caused a rapid & large increase in soil CO2 flux .. [which] coincided with profound shifts in the abundance of certain members of the soil microbial community.. natural DOM inputs may drive high rates of soil respiration by stimulat |
| 207 | Cleveland, C.J. | The direct and indirect use of fossil fuels and electricity in USA agriculture, 1910-1990 | 1995 | Energy in Agriculture | Journal | Agric. Ecosyst. Environ.; 55; 111-121 | English | Hardcopy:Partial; PDF:Full | Energy cost of labour is not included, but the need to include it in some situations is recognised. Energy cost of a capital input is obtained by multiplying its financial depreciation by the energy intensity (energy per financial unit) of the input. | The lack of a generally accepted accounting procedure led many analysts to omit the energy cost of labour (e.g. Leach, 1976). .. A common approach [to the measurement of the energy cost of capital] is to assess the energy required to produce a tonne of steel .. in a capital good .., the energy required to operate it and maintain it over its lifetime and then to allocate that energy over the expected lifetime of the [good] .. One problem with this approach is that the energy cost of materials changes with time .. |
| 401 | Clough, A. & Skjemstad, J.O. | Physical and chemical protection of soil organic carbon in three agricultural soils with different contents of calcium carbonate | 2000 | Soil Organic Carbon | Journal | Aust. J. Soil Res.; 38; 1005-1016 | English | Hardcopy:Partial | Lab. measurement of the amount of organic C physically protected within aggregates and through polyvalent cation-OM bridging. 11-43% OC was found in the clay fractions and 17-51% in the silt fractions. 17-40% of organic C was chemically protected in a condensed aromatic form, probably charcoal. | |
| 556 | Cogliastro, A., Domon, G. & Daigle, S. | Effects of waste-water sludge and wood-chip combinations on soil properties and growth of planted hardwood trees and willows on a restored site | 2001 | Lignin and CBW | Journal | Ecol. Eng.; 16; 471-485 | English | Hardcopy:Full; PDF:Full | Study of the effect of sewage sludge and chipped wood on young trees. | @; .. the combination of a large quantity of wood chips (200 m3/ha) with a small quantity of sludge (62-125 kg N/ha) led to a balanced foliar N/P ratio and to a reduction of N mineralisation in the soil. The rate of release of resources can be adjusted by |
| 948 | Cole, C.V., Duxbury, J., Freney, J.R., Heinemeyer, O., Minami, K., Mosier, A.R., Paustian, K., Rosenberg, N., Sampson, N., Sauerback, D. & Zhao, Q. | Global estimates of potential mitigation of greenhouse gas emissions by agriculture | 1997 | Greenhouse Gases | Journal | Nutr. Cycl. Agroecosyst.; 49; 221-228 | English | Hardcopy:Partial; PDF:Full | Out of a worldwide total of 1727 Mha of arable land, 822 Mha were originally forest and 438 Mha were grassland. | The emissions of CO2, CH4 and N2O from agriculture together account fort approximately one fifth of the annual increase in radiative forcing of climate change. When land use changes involving biomass burning and soil degradation are included the overall radiative forcing amounts to one third of the (anthropogenic impact. .. CH4 and N2O are the major contributors to agricultural impacts, as the agricultural sector produces about 50% and 70% respectively of the total anthropogenic emissions of these gases.; This shows a current global stock of organic C in cultivated lands 167 Pg C and a historical loss from these soils of 55 Pg c. .. They estimated global losses of soil C since 1860 to be 30 Pg C (15% of the total 170 Pg C lost from vegetation and soils) or 41 Pg C since the beginning of settled agriculture. |
| 287 | Colla, G., Mitchell, J.P., Joyce, B., Huyck, L., Wallender, W., Temple, S.R., Hsiao, T. & Poudel, D.D. | Soil physical properties and tomato yield and quality in alternative cropping systems | 2000 | Cover Crops; Organic Farming | Journal | Agron. J.; 92 (5); 924-932 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the effect of a change from conventional to low-input and organic tomato growing | No differences in .. soil BD and water-holding capacity were found.; Tomato yields did not differ among systems in either year. Fruit quality was highest in the conventional 4-year system.; Winter cover cropping .. has been shown to increase soil water retention and infiltration and to decrease soil surface strength.; High infiltration rates can increase irrigation needs and the cover crops can deplete soil moisture as they mature. |
| 1199 | Collins, H.P., Elliott, E.T., Paustian, K., Bundy, L.G., Dick, W.A., Huggins, D.R., Smucker, A.J.M. & Paul, E.A. | Soil carbon pools and fluxes in long-term corn belt agroecosystems | 2000 | Soil Organic Carbon | Journal | Soil Biol. Biochem.; 32 (2); 157-168 | English | Hardcopy:Partial; PDF:Full | Field expt. to the sizes of C pools and fluxes in arable soils | x; Measurement of the natural abundance of 13C made it possible to follow the in@fluence of continuous maize on SOC accumulation. The active pools comprised 3-8% of the SOC with an average field MRT of 100 d. The slow pools comprised 50% of SOC in the surface and up to 65% in subsoils. They had field MRTs from 12-28 y for C4-C and 40-80 y for C3-derived C depending on soil type and location. Notill management increased the MRT of the C3-C by 10-15 y above conventional (tillage. The resistant pool (Cr) decreased from an average of 50% at the surface to 30% at depth. |
| 1529 | Comia, R.A., Stenberg, M., Nelson, P., Rydberg, T. & Håkansson, I. | Soil and crop responses to different tillage systems | 1994 | Tillage | Journal | Soil Tillage Res.; 29; 335-355 | English | Hardcopy:Partial | 8-year expt. to study the effect of tillage on soil properties, plant development and crop yield. The differences were small. | At most sites and during most years of the expt. the alternative tillage systems resulted in greater yields than conventional tillage. However, the differences were often not significant .. |
| 208 | Conforti, P. & Giampietro, M. | Fossil energy use in agriculture: an international comparison | 1997 | Energy in Agriculture | Journal | Agric. Ecosyst. Environ.; 65; 231-243 | English | Hardcopy:Partial | Energy output/input ratios for crop production are compared for 75 countries. They are highest in countries with primitive agriculture, such as Uganda, Niger and the Central African Republic, and lowest in the countries with industrialised agriculture. Four countries (Japan, New Zealand, Switzerland and Finland) have a ratio of less than one, showing a net energy loss. Labour, animals and transport were not included in the calculations. | .. the rate of consumption of fossil energy is certainly faster than that of its production. This implies that current agricultural techniques are unsustainable in the long run .. |
| 889 | Conrad, R. | Soil microorganisms as controllers of atmospheric trace gases (H2, CO, CH4, OCS, N2O and NO) | 1996 | Greenhouse Gases; Soil Microorganisms | Journal | Microbiol. Rev.; 60 (4); 609-640 | English | Hardcopy:Partial | Review of biological controls on the emission of certain gases from the soil | The most dramatic change in the past was that from an anoxic to an oxic atmosphere. This change occurred slowly over about 2.5 Gyr and was caused by the emergence of oxygenic photosynthesis.; .. in agricultural soil microorganisms are present at billions per g of soil and constitute a biomass of approximately 500 kg of C per ha, which corresponds to about 1 sheep per 100 m2 [100 sheep per ha].; .. the existence of a temperature optimum .. is an unambiguous indication of a biological reaction. |
| 1200 | Constantinides, M. & Fownes, J.H. | Nitrogen mineralization from leaves and litter of tropical plants: relationship to nitrogen, lignin & soluble polyphenol concentrations | 1994 | Lignin and CBW; Mineralisation; Soil N Dynamics | Journal | Soil Biol. Biochem.; 26 (1); 49-55 | English | Hardcopy:Partial | Lab. expt. to study the decomposition of leaves and litter from various leguminous and non-leguminous tropical plants. The results of this study differed from those of other studies of leguminous plant residues, where soluble polyphenols or polyphenol/N ratios correlated better with rates of net N release than initial N content or lignin/N ratios. | .. the percent of leaf N accumulated was most highly correlated with initial N concentration. Phosphorus and the ratios lignin/N and (lignin+polyphenol)/N also strongly correlated with N accumulation .. Over our wide range of materials initial soluble polyphenols were secondary to initial N .. |
| 1201 | Cook, B.D. & Allan, D.L. | Dissolved organic carbon in old field soils: total amounts as a measure of available resources for soil mineralization | 1992 | Mineralisation; Soil Organic Carbon | Journal | Soil Biol. Biochem.; 24 (6); 585-594 | English | Hardcopy:Partial | Lab. measurement of C & N mineralisation during a 210-day incubation of soil from five previously cultivated old fields. The initial potentially mineralisable organic C & N ranged from 14% to 26% and from 14% to 33% of total SOC and SON respectively. | .. there was no obvious relationship between DOC and instantaneous rates of mineralisation.; It is assumed that all the dissolved substances are labile and utilised rapidly. However, recalcitrant molecules may represent a significant portion of the DOC. |
| 1202 | Cookson, W.R., Cornforth, I.S. & Rowarth, J.S. | Winter soil temperature (2-15ºC) effects on nitrogen transformations in clover green manure amended or unamended soils; a laboratory and field study | 2002 | Green Manure; Soil N Dynamics | Journal | Soil Biol. Biochem.; 34 (10); 1401-1415 | English | Hardcopy:Partial; PDF:Full | Expt. to study the effect of fluctuating winter temperatures in a temperate region on the release of N from plant residues | Nitrate-N was the dominant form of mineral-N throughout the incubation expt. in amended soil incubated at 10 or 15$C.; Gross nitrification was initially (756 days) inhibited in amended soil incubated at 2 or 5$C, causing an accu`mulation of NH4+-N. However, after 77 days at 2 or 5$C, gross nitrification rates (increased, such that NO3--N increased to concentrations which were greater than those of NH4+-N. This suggests that nitrifying bacteria took longer to acclimatise to the cold conditions [<10$C] than ammonifying microorganisms.; Decreasing soil temperature from 15 to 2$C caused an initial increase in mineral-N, which was quickly followed by rapid immobilisation of mineral-N; gross immobilisation rates were up to 2.8-fold greater than gross mineralisation rates. Similarly, under field conditions microbial biomass N and gross immobilisation increased with decreasing soil temperature, suggesting there was population growth of adapting micro-flora.; This research has shown that significant mineral-N is released from soil amended with clover residues at temperatures as low as 2$C.Therefore, the incorporation of N-rich plant material should be delayed until spring to avoid winter N leaching. |
| 455 | Corbeels, M., Hofman, G. & Cleemput, O. van | Simulation of net N immobilisation and mineralisation in substrate-amended soils by the NCSOIL computer model | 1999 | Mineralisation; Stockless Farming; Soil N Dynamics | Journal | Biol. Fertil. Soils; 28; 422-430 | English | Hardcopy:Full; PDF:Full | Modelling soil N dynamics, compared with expt'l data, for 4 org. treatments | Net mineralisation was detected earliest for the sunflower-stalk treatment (on day 14), while the other treatments showed no net mineralisation until day 52. These differences in lag periods were presumably related to the different C/N ratios of the substrates.; .. microorganisms utilise available N from the soil environment when decomposing organic material that has a high C/N ratio, which is afterwards released at a slower rate by subsequent microbial colonisers.; The C/N ratio of bacteria is an important factor in N mineralis'n & is known to change with time.. a distinction between an autochthonous (decomposing native SOM) and a zymogenous microbial population (decomposing added residues), each with a fixed C/N ratio, change[s] the C/N ratio of the total microbial biomass |
| 90 | Cormack, W.F. | Testing a stockless arable organic rotation on a fertile soil | 1999 | Organic Farming; Stockless Farming | Book | Olesen, J.E., Eltun, R., Gooding, M.J., Jensen, E.S & Köpke, U. (eds); Designing & testing crop rotations for organic farming. Proceedings from an international workshop; | English | Hardcopy:Full; Wordperfect:Full | A report of the same expt. as in Cormack (1997), except that the soil aggregate stability and N content are not reported here. | See Cormack (1997). |
| 158 | Cormack, W.F. | Testing the sustainability of a stockless arable rotation on a fertile soil in Eastern England | 1997 | Stockless Farming | Book | ; 3rd ENOF concerted action workshop, Ancona, Italy; | English | Hardcopy:Full | A report, after one complete rotation, of a field-scale expt. in stockless arable farming conducted at A.D.A.S., Terrington, on 10 ha of silty clay loam.The rotation used was: potatoes, winter wheat, spring beans and spring wheat. The results were good on both agronomic and financial criteria. SOM, aggregate stability, N, P & K content and crop yields are reported. | Organic crops have yielded well ..; .. the organic rotation has been consistently more profitable than the conventional.; However, profitability has been dependent on .. price premiums and on arable aid and set-aside payments.; .. the .. expt. shows that such a [stockless organic] rotation may be .. more profitable than conventional, at least on a water and nutrient-retentive soil.; .. perennial weeds .. are increasing.; Soil available phosphorus declined .. Reddzlaag (calcined calcium alumino-phosphate, 14% P) .. was applied .. |
| 933 | Cornelissen, J.H.C. & Thompson, K. | Functional leaf attributes predict litter decomposition rate in herbaceous plants | 1997 | Miscellaneous; Soil Organic Carbon | Journal | New Phytol.; 135; 109-114 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the correlation between leaf litter decomposition rates and various attributes of the leaves of grasses and herbaceous dicot plants | Graminoid monocots had physically tougher leaves with higher silicon contents than did herbaceous dicots and this corresponded with the lesser decomposibility of the former. Total base content of living leaves was a good predictor of litter decomposition rate.. In the monocots litter decompos'n rate was strongly predicted by leaf potassium content .. In the dicots the relationship between total leaf base content & litter decompos'n rate was not unambiguously explained by growth-related leaf attributes, possibly because of the considerable calcium uptake by dicots, which varies according to calcium availability in the soil. |
| 1590 | Cornforth, J.W. | Energy out of agriculture: plants as a source of fuel and power | 1975 | Energy Resources | Journal | Span; 18 (1); 10-11 | English | Hardcopy:Full | The use of energy crops and plant wastes. Various methods of getting usable energy from photosynthetic biomass are considered. | .. by some plants (e.g. sugar cane), growing as a crop in ideal conditions .. the best performance that can be attained at present is around 3% .. of the total [solar] radiation incident on the land throughout the year. .. 1% fixation of solar energy .. is the maximum attainable now .. in temperate climates ..; A tropical forest can fix solar energy at a rate of 90 MJ/sq m/year or more. .. Tropical swamps can reach 140 MJ/sq m/year .. |
| 209 | Cowell, S.J. & Parkinson, S. | Localisation of UK food production: an analysis using land area and energy as indicators | 2003 | Energy in Agriculture; Stockless Farming | Journal | Agric. Ecosyst. Environ.; 94 (2); 221-236 | English | Hardcopy:Partial | Comparison of various categories of imported and U.K.-produced food in respect of the transport energy and the area of land used. Tables are given of the distance travelled and the land requirements of each category of food. | .. based on the land use indicator, localisation of UK food production is possible, although this would involve considerable changes in individuals' food consumption patterns.; .. meat and other animal products require the largest land area in the UK ..; Since plant products can be produced more efficiently (mass per ha) than animal products for human consumption, a reduction in consumption of animal products in favour of plant products is likely to facilitate the localisation of food production. .. meat products have yields as low as 0.2 t/ha, whereas grain yields range from 4.4 to 6.8 t/ha. .. about 50% of the UK consumption of cereals is by livestock.; .. another survey shows that the percentage of vegetarians in the UK has grown to 7%, a doubling in the last ten years .. |
| 1610 | Coûteaux, M.M., Bottner, P. & Berg, B. | Litter decomposition, climate and litter quality | 1995 | Soil Organic Carbon | Journal | Trends Ecol. Evol.; 10 (2); 63-66 | English | Hardcopy:Full; PDF:Full | Review of the factors affecting the rate of litter decomposition | Litter decompos'n is controlled by three main factors: climate, litter quality and the nature and abundance of the decomposing organisms. Climate is the dominant factor in areas subjected to unfavourable weather conditions, whereas litter quality largely prevails as the regulator under favourable conditions. |
| 375 | Craft, C.M. & Nelson, E.B. | Microbial properties of composts that suppress damping-off & root rot of creeping bentgrass caused by Pythium graminicola | 1996 | Compost & Biocontrol | Journal | Appl. Environ. Microbiol.; 62 (5); 1550-1557 | English | Hardcopy:Partial; PDF:Full | Lab. & field expt. to investigate possiblc connections between the microbial activity of a compost and its potential to suppress soil-borne diseases | .. suppression of Pythium diseases of creeping bentgrass in batches of brewery sludge and Endicott biosolids composts, and possibly in other suppressive composts .., is related directly to the microbial activities in the composts.; Disease suppressiveness was .. reduced or eliminated in heated composts. Amending heated composts with smallamounts of non-heated compost restored suppressive properties and partially restored microbial populations to wild-type levels. |
| 376 | Crawford, D.L. & Crawford, R.L. | Microbial degradation of lignocellulose: the lignin component | 1976 | Lignin and CBW | Journal | Appl. Environ. Microbiol.; 31 (5); 714-717 | English | Hardcopy:Full; PDF:Full | 700-hour lab. expt. to study the decomposition of lignin in soil, using wood labelled with 14C-phenylalanine. | The cellulose in our substrates may speed lignin degradation by acting as .. an additional source of energy for lignocellulose degraders in soil .. lignin degradation .. requires a readily metabolisable substrate such as cellulose. |
| 607 | Crawford, D.L. & Crawford, R.L. | Microbial degradation of lignin | 1980 | Lignin and CBW | Journal | Enzyme. Microb. Technol.; 2; 11-22 | English | Hardcopy:Full | Review of existing knowledge of the microbial degradation of lignin | Much of the lignin bio-synthesised by plants is mineralised and returned to the xatmosphere as CO2.; certain fungi of the white rot group, and possibly other @fungi and bacteria, completely decompose lignin to CO2 and water. Other fungi and bacteria apparently degrade lignin incompletely.; [with] white rot fungi .. lignin degradation proceeds by way of extracellular mixed-function oxygenases and dioxygenases, which catalyse demethylations, hydroxylations and ring-fission reactions within a largely intact polymer, concomitant with some release of low molecular weight lignin fragments.; White-rot fungi deplete carbohydrate and lignin simultaneously as they decay wood, although some species actually decompose the lignin .. in preference to the cellulosic components. |
| 377 | Crawford, D.L., Crawford, R.L. & Pometto, A.L. | Preparation of specifically labelled 14C-(lignin) and 14C-(cellulose)lignocelluloses and their decomposition by the microflora of soil | 1977 | Lignin and CBW | Journal | Appl. Environ. Microbiol.; 33 (6); 1247-1251 | English | Hardcopy:Partial; PDF:Full | 700-hour lab. expt. to study the decomposition of natural lignocellulose in soil, using wood @labelled by feeding plants with 14C-phenylalanine or 14C-glucose to label the lignin and the cellulose respectively. After 700 hours about 4% of the lignin and 28% of the cellulose had been mineralised to CO2. There was a lag of several weeks before significant mineralisation of lignin took place. | The lags are probably the result of the mechanism of decomposition .. Considerable preliminary attack on the polymeric structure,particularly of lignin, must occur before appreciable oxidation to 14CO2 is possible.; .. the cellulosic components of lignocelluloses would be completely recycled .. within relatively short times .. Lignin components, on the other hand, would likely accumulate over time .. and are important in processes such as humification. |
| 725 | Cross, A.F. & Schlesinger, W.H. | A literature review and evaluation of the Hedley fractionation: applications to the biogeochemical cycle of soil phosphorus in natural ecosystems | 1995 | Phosphorus Cycling | Journal | Geoderma; 64; 197-214 | English | Hardcopy:Full; PDF:Full | Review of published results on the P content and extracts (fractions) in different soil types. Total soil P varies between 0.1 and 0.75 g/g soil. The labile P (sum of resin and bicarb extracts), which is the form of P available to plants, is 2-10% of total soil P. SOP is 5-35% of total P, depending on soil type - it increases with soil weathering. | .. the total soil P pool decreases as a function of soil development.; .. the dominant processes that regulate the soil P cycle are the geochemical reactions.; .. the pool of primary phosphate declines and the stable organic pool increases during soil development. .. phosphorus becomes geochemically fixed to the iron and aluminium oxides in the more highly weathered soils. |
| 856 | Crovetto, C.C. | No-till development in Chequen Farm and its influence on some physical, chemical and biological parameters | 1998 | Tillage | Journal | J. Soil Water Conserv.; 53 (3); 194-199 | English | Hardcopy:Partial | A report on changes in soil qualities on a farm in Chile that has been under zero tillage for many years. Soil qualities (including microbiological activity) and crop yields have improved. | After 38 years of absence of tillage the soils present today have superior physical, chemical and biological properties that increase crop yields.; Notill improves the OM levels ..; The mesofauna of the no-till soil in general was strongly favoured as compared to till soil. .. during the period studies, insects, acarus, nematodes, centipedes, worms, platyhelminths, molluscs and crustaceans made a higher count than that of the soil under traditional till. |
| 65 | Cunha Queda, A.C., Vallini, G., Agnolucci, M., Coelho, C.A., Campos, L. & Sousa, R.B. de | Microbiological and chemical characterisation of composts at different levels of maturity, with evaluation of phytotoxicity and enzymatic activities | 2002 | Compost & Biocontrol | Book | Insam, H., Riddech, N. & Klammer, S. (eds.); Microbiology of Composting; | English | Hardcopy:Partial; Wordperfect:Full | Lab. expt. to study the stability, microbiology and phytotoxicity of various composts | During the active phase the most easily biodegradable materials are transformed & partially mineralised; the OM becomes stabilised as a consequence of the intense microbial activity. The curing phase is characterised by the conversion of part of the stabilised OM into humic substances. Thus, while reaching compost stability can be regarded as the result of high-rate microbial reactions occurring throughout the active phase of the process, compost maturity appears .. as the effect of the curing phase.; .. the compost C/N ratio depends on the ratio between relative contents in carbon and nitrogen in the initial matrix, on the presence of organic fractions refractory to biodegradation in the initial substrate and on the dynamic evolution of the composting process. |
| 456 | Curci, M., Pizzigallo, M.D.R., Crecchio, C., Mininni, R. & Ruggiero, P. | Effects of conventional tillage on biochemical properties of soils | 1997 | Soil Microorganisms; Tillage | Journal | Biol. Fertil. Soils; 25 (1); 1-6 | English | Hardcopy:Full; Wordperfect:Full | Field expt. to study the effect of different tillage regimes on the distribution in the soil of various microbially derived enzymes and microbial biomass | .. the influence of three conv'l tillage systems (shallow ploughing, deep ploughing & scarification) at different depths on the distrib'n & activity of enzymes, microbial biomass & nucleic acids in a cropped soil was investigated.; Activity in the upper layer (0- 20 cm) was higher in the plots tilled by shallow ploughing and scarification than in those tilled by deep ploughing. |
| 288 | Curran, B.S., Kephart, K.D. & Twidwell, E.K. | Oat companion crop management in alfalfa establishment | 1993 | Green Manure | Journal | Agron. J.; 85 (5); 998-1003 | English | Hardcopy:Full | Field expt. to compare various methods of establishing a lucerne crop, especially with and without oats as a companion crop. (Oats are sown with lucerne to reduce erosion and weeds before the lucerne is established.) The best lucerne yield in the first year was in the hand-weeded plot without oats. This and the herbicide-treated plots were much less weedy than the plots with oats and the control plot, which had no weed-control treatment. In the second year, however, all treatments gave similar yields and were practically weed-free. | |
| 416 | Daily, G.C. & Ehrlich, P.R. | Population, sustainability and Earth's carrying capacity | 1992 | Sustainability | Journal | Bioscience; 42 (10); 761-771 | English | Hardcopy:Partial | Sustainability is discussed in terms of the environmental impact of the world's population, an estimate of available resources and the relationship between the two. | Given the current technologies, levels of consumption and socio-economic organisation, has ingenuity made today's population sustainable? The answer to this is clearly no .. |
| 544 | Daily, G.C. & Ehrlich, P.R. | Socioeconomic equity, sustainability and Earth's carrying capacity | 1996 | Sustainability | Journal | Ecol. Appl.; 6 (4); 991-1001 | English | Hardcopy:Full | Review of the relationship between sustainability and socioeconomic equity | .. inequalities themselves help perpetuate poverty, which generates vicious cycles involving deleterious and sometimes irreversible impacts on bio-physical components of Earth's life-support systems. .. they hinder cooperation among parties of differing socioeconomic status - co-operation purportedly required for averting potentially disastrous population- & environment-related problems.; Social carrying capacity is the maximum popul'n size that an areas can sustain under a given social system .. social CC is necessarily smaller than bio-physical CC ..; What may be needed are structural changes in the economy, so that children no longer constitute sources of income, but are converted into consumer durables - expensive items that compete for consumption expenditures with [TV] .. and the like.; .. it is imperative to find ways of reducing the scale of the human enterprise .. empowering Homo sapiens to end today's overshoot and return to sustainable numbers and lifestyles. |
| 1203 | Dalenberg, J.W. & Jager, G. | Priming effect of some organic additions to 14C-labelled soil | 1989 | Green Manure; Priming Effect; Soil Organic Carbon | Journal | Soil Biol. Biochem.; 21 (3); 443-448 | English | Hardcopy:Partial | Lab. expt. to establish the magnitude of the priming effect of various soil organic amendments. Of the substrates added only the pure amino-acids (which are not present in nature) left a negative carbon balance in the soil. | All other substrates ... left enough residues, including biomass, to fully compensate for the loss due to priming. The fear of the 'humus-eating effect of green manures' thus is unfounded ..; If priming leads to extra decomposition of SOM, then only fraction (a) [fresh plant residues] can be involved. [but] In our soil fraction (a) was no longer present .. [so] .. biomass was the only source of C that could be primed in our soil .. |
| 949 | Dalgaard, T., Halberg, N. & Kristensen, S. | Can organic farming help to reduce N-losses? Experiences from Denmark | 1998 | Organic Farming; Stockless Farming | Journal | Nutr. Cycl. Agroecosyst.; 52; 277-287 | English | Hardcopy:Partial; PDF:Full | Modelling is used to compare N losses in conventional and organic dairy and pig farming | .. pig farming was found to have a higher N-efficiency than dairy farming. Organic pig production had a lower N-efficiency and a higher N-surplus per kg meat than conventional pig production. .. Organic dairy farming had a higher N-efficiency and a lower N-surplus per kg milk than conventional dairy farming.; .. a positive correlation between livestock density and N-surplus ha-1 was found for dairy farming. For all simulated livestock densities, fodder feeding intensities and soil types, organic systems showed a lower N-surplus per unit of milk produced than conventional systems. .. the present Danish milk production could be achieved with a 24% lower total N-surplus ..if conventional dairy farming with 1.7 LSU ha-1 is converted to organic dairy H farming with 1.1 LSU ha-1 [and] average N-surplus per t milk and average N-surplus per ha in Denmark could be reduced by 25% and 50% respectively.; Animal production intensity was measured in LSU ha-1, where 1 LSU (Livestock Unit) corresponds to one 550 kg dairy cow, 3 sows or 30 porkers produced per year. |
| 210 | Dalgaard, T., Halberg, N. & Porter, J.R. | A model for fossil energy use in Danish agriculture used to compare organic and conventional farming | 2001 | Energy in Agriculture; Organic Farming | Journal | Agric. Ecosyst. Environ.; 87; 51-65 | English | Hardcopy:Full; PDF:Full | Modelling energy use in conventional and organic agriculture | The energy use was generally lower in the organic than in the conventional system, but yields were also lower. Consequently, conventional crop production had the highest energy production, whereas organic crop production had the highest energy efficiency. |
| 1008 | Dam, A.M. van | Understanding the reduction of nitrogen leaching by cover crops | 2006 | Cover Crops; Soil N Dynamics | Book | Dam, A.M. van; Understanding the reduction of nitrogen leaching by cover crops; | English | Hardcopy:Partial; Wordperfect:Partial | Lab. expt. to study the factors affecting the nitrogen uptake of cover crops | .. sowing date determines the potential N uptake capacity of the cover crop. x.. the simulated uptake capacity of a cover crop exceeds 200 kg N ha-1 when the crop is sown in the first half of August. For rye, the uptake capacity decreases on average by 3.3 kg N ha-1 per day postponement of sowing.; For a maximum N availability to the succeeding crop, a rye cover crop on a sandy soil is best incorporated in soil three months before the planting the next crop. Deviations up to a month from the optimal date had only a small effect on N available to (the next crop (2 kg N ha-1). |
| 1204 | Danso, S.K.A., Palmason, F. & Hardaarson, G. | Is nitrogen transferred between field crops? Examining the question through a sweet blue lupin (Lupinus angustifolius)-oats (Avena sativa) intercrop | 1993 | Green Manure; Soil N Dynamics | Journal | Soil Biol. Biochem.; 25 (8); 1135-1137 | English | Hardcopy:Full | Field expt. to investigate the transfer of N from lupin to oats. The authors purport to demonstrate that there is no transfer. | .. legumes in an intercrop have a diminished soil N uptake ability, enabling an intercropped non-N2-fixing crop to absorb more N than it would when cropped alone. The contribution from this soil N-sparing effect was shown in crop rotation studies to be more important than N transfer. This was the case in our `study, as revealed by the 15N enrichment in sole oats vs. mixed oats; a (significant N transfer would have been indicated if mixed oats had a lower 15N enrichment than sole oats, which was not so. |
| 1414 | Dao, T.H. | Tillage and crop residue effects on carbon dioxide evolution and carbon storage in a paleustoll | 1998 | Greenhouse Gases; Soil Organic Carbon | Journal | Soil Sci. Soc. Am. J.; 62 (1); 250-256 | English | Hardcopy:Partial | Field expt. to compare the soil respiration and microbial biomass of soils under plough and zero tillage | The proportion of soil OC respired in the 60-day period was twice as great under MP [ploughing] than NT [zero tillage], accounting for 0.42% to 0.58% and 0.19% to 0.22% respectively.; Daily average temperatures in the 0- to 2.0-cm depth were 0.5$ to 3.4$C higher under MP than NT, increasing microbial ATP, `biomass C and CO2 fluxes. |
| 512 | Davenport, J.R. & Thomas, R.L. | Carbon partitioning and rhizodeposition in maize and brome grass | 1988 | Roots & Rhizodeposition; Soil Organic Carbon | Journal | Can. J. Soil Sci.; 68 (4); 693-701 | English | Hardcopy:Full | Modelling the belowground C deposition of the two crops. Calculated on the same weight of aboveground dry matter (10,000 kg/ha) brome and maize yield 3125 and 2500 and 562 and 674 kg/ha from the root and extra-root depositions respectively. (Extra-root material means all rhizodeposits other than root tissue.) Only 10% of all C assimilated by maize goes belowground, whereas 40% does in the case of brome grass. | The amount of C input into the soil determines the substrate for soil microorganisms and is, therefore, the controlling factor in the relationship between crops and soil structure .. maize being a crop that has been identified as detrimental to sustained stable soil structure, while brome grass provides a definite enhancement of soil structure. |
| 1611 | Dawson, T. & Fry, R. | Agriculture in nature's image | 1998 | Sustainability | Journal | Trends Ecol. Evol.; 13 (2); 50-51 | English | Hardcopy:Full; PDF:Full | Review of research into farming that mimics nature | .. the natural ecosystem of any region is adapted to .. resource constraints and therefore provides a site-specific model for sustainability if well mimicked by agriculture.; Alley cropping has largely failed in Africa .. because of insufficient knowledge of where the plants extracted their resources and/ or their phenological patterns of resource use and .. insufficient attention to farmers' immediate economic needs.; Any mimic system designed with a view to sustainability should .. be designed within an adoption framework with clear links to the farmers who will use it. There may be long time lags between implementation and pay-back, so part of the mosaic should supply short-term profits for the farmer.; Conventional agriculture is focused on short-term gains ..; There will be no universal recipe for .. sustainable agriculture; what works for the tropics is not likely to work for south Australia because of different climatic, ecological and socio-economic constraints. |
| 59 | Dazhong, W. & Pimentel, D. | Energy flow in agroecosystems of north-east China | 1990 | Agricultural Ecology | Book | Gliessman, S.R. (ed.); Agroecology - researching the ecological basis for sustainable agriculture; | English | Hardcopy:Partial | Energy inputs and outputs are estimated in three different farming systems - traditional organic, commune and state farm - in Hailun county, China.Tables are given for the various inputs and outputs of each crop system and each livestock system and for the yields of crops and crop residues. Labour is reckoned as 6 MJ per eight-hour day. Horses are reckoned as 50 MJ per five-hour day. | no quotations |
| 338 | Debosz, K., Petersen, S.O., Kure, L.K. & Ambus, P. | Evaluating effects of sewage sludge and household compost on soil physical, chemical and microbiological properties | 2002 | Compost & Biocontrol | Journal | Appl. Soil Ecol.; 19 (3); 237-248 | English | Hardcopy:Partial; PDF:Full | Expt. to test the effects of org. wastes (composted household waste & processed sewage sludge) on a wide range of soil physical and microbiological properties | In general effects of waste amendment were positive but moderate compared to the dynamics observed in unamended soil and mainly occurred in the first several weeks after amendment. .. there were no accumulated effects of waste amendment on the fraction of soil in wet-stable aggregates or on the microbiological properties tested, which supported the observation .. that effects of organic wastes were transient. |
| 1530 | Deen, W. & Kataki, P.K. | Carbon sequestration in a long-term conventional versus conservation tillage experiment | 2003 | Soil Organic Carbon; Tillage | Journal | Soil Tillage Res.; 74 (2); 143-150 | English | Hardcopy:Partial; PDF:Full | 25-year field expt. to compare the yields of maize under zero tillage and under chisel and mouldboard ploughing, with or without secondary tillage | The ZT treatments had a higher SOC concentration in the surface layer compared to other tillage treatments ... However ... method of tillage ... also influenced soil bulk density. When SOC was calculated using an equivalent soil mass basis, SOC storage in the 0-40 cm layer, which encompasses a typical plough layer in eastern Canada, was not affected by time or method of tillage. |
| 402 | Degens, B.P. | Macro-aggregation of soils by biological bonding and binding mechanisms and the factors affecting these: a review | 1997 | Soil (General) | Journal | Aust. J. Soil Res.; 35; 431–459 | English | Hardcopy:Partial | Review of the literature dealing with labile mechanisms of bonding (through adhesive organic compounds) and binding (through fungal hyphae and roots) involved in stabilising soil into macroaggregates (>250m) | Carbohydrate C that is microbial in origin appears to be most effective in stabilising soil into aggregates.; .. fungal hyphae hag been consistently found to stabilise soil into aggregates by physical enmeshment of soil particles.; Roots appear to stabilise soil into aggregates by enmeshment of soil particles, frequently in conjunction with VAM hyphae.; The contribution of mycorrhizal hyphae to the stabilisation of soil into macroaggregates may be prolonged compared with that of saprophytic hyphae. |
| 1205 | Degens, B.P. | Decreases in microbial functional diversity do not result in corresponding changes in decomposition under different moisture conditions | 1998 | Soil Microorganisms | Journal | Soil Biol. Biochem.; 30 (14); 1989-2000 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the effect of microbial diversity on microbial community functioning in soil | .. the decompos'n function of soil with reduced functional diversity can be diminished under optimum moisture conditions, but is not invariably reduced when assessed under sub-optimal moisture conditions. .. decreases in the functional diversity of soil microbial communities may not consistently result in declines in soil functioning.; The high degree of functional redundancy in soil microbial communities may result in there being no effect of changes in microbial diversity on the function of the communities. |
| 1206 | Degens, B.P. & Sparling, G.P. | Changes in aggregation do not correspond with changes in labile organic C fractions in soil amended with 14C-glucose | 1996 | Soil Organic Carbon; Soil (General) | Journal | Soil Biol. Biochem.; 28 (4/5); 453-462 | English | Hardcopy:Partial | 56-day lab. expt. to study the changes in carbohydrate content, microbial biomass and aggregation in a sandy soil amended with glucose | @; In this sandy soil changes in carbohydrate C fractions, 14C microbial biomass and 14C [microbial] products were not consistently related to changes in aggregate stability. .. Our results contrasted with investigations of loam and clay soils, where aggr |
| 339 | Degens, B.P., Sparling, G.P. & Abbott, L.K. | Increasing the length of hyphae in a sandy soil increases the amount of water-stable aggregates | 1996 | Soil Microorganisms; Soil (General) | Journal | Appl. Soil Ecol.; 3; 149-159 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the effect of hyphal length on aggregation in a sandy soil | .sand grains in the aggregates appeared to be linked together only by hyphae .. indicating little involvement of microbial polysaccharides in stabilising the aggregates.; The amounts of dry-stable aggregates .. were generally increased by 63-147% in the amended soils compared to non-amended soils and 27 to 33% of these aggregates were water-stable aggregates ..; Mycorrhizal hyphae may be more important than saprophytic hyphae in stabilising aggregates because aggregates stabilised by the hyphae can persist in .. soil for up to 22 weeks after the plants had died .. the effect of saprophytic fungi in stabilising aggregates can be transitory.; .. the resulting hyphal length was more strongly correlated with aggregation in the soils containing greater than 67% sand compared to those soils containing more silt and clay. |
| 612 | Delgado, A. & Torrent, J. | Phosphate-rich soils in the European Union: estimating total plant-available phosphorus | 1997 | Phosphorus Cycling | Journal | Eur. J. Agron.; 6; 205-214 | English | Hardcopy:Partial | Expt. to find a reliable method to measure soil total plant-available P | xIn the 12 soils tested total P (organic + inorganic) averaged 775 mg kg-1 soil, @total P uptake averaged 110 mg kg-1 soil and the total plant-available P averaged 170 mg kg-1 soil. |
| 857 | Delgado, J.A. & Follett, R.F. | Carbon and nutrient cycles | 2002 | Phosphorus Cycling; Soil Organic Carbon | Journal | J. Soil Water Conserv.; 57 (6); 455-464 | English | Hardcopy:Full | Review of the literature on the role of SOM in agricultural soils, especially its role in nutrient recycling. For the release of nutrients from crop residues the C/nutrient ratio is critical. The soil C pool is split into organic and inorganic in the ratio 1.9/1, is 3.2 times that in the atmosphere and 4 times that in terrestrial vegetation. The SOC pool can be divided into three: active C (mainly live microbes and microbial products) with a turnover of 1-5 years, the slow pool, which is physically protected and has a turnover of 20-40 years, and the passive pool, which is recalcitrant and turns over in 200-1500 years. Greater clay content increases the protection of SOM from mineralisation. 58% of the N and 70% of the P in FYM is mineralised. | C can contribute positively to soil quality by improving porosity, available water holding capacity and cation exchange capacity ..; SOM contributes to a better soil structure and aggregate formation .. serves as a storage form of N, P, and S and helps in the cycling of essential nutrients.; C management should coordinate the mineralisation of nutrients from crop residues & other organic sources with the time of greater uptake during the growing season.; Although total N deposition [from the atmosphere] can vary depending on the region, it is low on average. .. the total deposition at North Platte .. for 2000 was about 4 kg N/ha, while at Big Springs it was .. 7.2 kg N/ha. |
| 211 | Delve, R.J., Cadisch, G., Tanner, J.C., Thorpe, W., Thorne, P.J. & Giller, K.E. | Implications of livestock feeding management on soil fertility in the smallholder farming systems of sub-Saharan Africa | 2001 | Stockless Farming; Soil N Dynamics | Journal | Agric. Ecosyst. Environ.; 84 (3); 227-243 | English | Hardcopy:Partial; PDF:Full | Expt. to compare the effect on cattle of feeding them barley straw, either alone or with one of three different additives (two forage legumes and poultry manure). The N content of the faeces was examined, as was the partitioning of N between faeces and urine. The rate of mineralisation of N was measured when the faeces from the various diets were incubated [with soil ?], as compared with when the feed itself was incubated, to assess the effect of the feed passing through the cattle. | A choice must be made between the allocation of organic resources: whether they should be used for livestock feed or as organic fertilisers in crop production. Animal manures are of major importance in nutrient cycling but generally of poor quality to supply plant nutrients and organic resources vary widely in their ability to provide nutrients directly for crop growth.; The option of feeding the plant materials to ruminant livestock and then adding the faeces to the soil did increase the rate of N mineralisation .. and produced larger N uptake in maize grown in pots .. the lower the quality of the feed material, the more beneficial the application of faeces is over direct application of the plant material to the soil. |
| 636 | Denef, K. & Six, J. | Clay mineralogy determines the importance of biological versus abiotic processes for macroaggregate formation and stabilization | 2005 | Soil (General) | Journal | Eur. J. Soil Sci.; 56 (4); 469-479 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the factors affecting macroaggregate formation in soils of differing mineralogy | Control macroaggregates in the kaolinitic soil were formed out of silt and clay particles without accumulating C. Residue input and plant growth had a greater positive effect on macroaggregate formation in the illitic than in the kaolinitic soil. ... kaolinitic soils can rapidly form macroaggregates independent of biological processes due to physical or electrostatic interactions between the 1:1 clay minerals and oxides. ... biological processes led to stronger organic bonds between the illite compared with the kaolinite clay, resulting in more macroaggregates with long-term stability in the illitic ... soil. |
| 637 | Denef, K. & Six, J. | Contributions of incorporated residue and living roots to aggregate-associated and microbial carbon in two soils with different clay mineralogy | 2006 | Roots & Rhizodeposition; Soil Organic Carbon | Journal | Eur. J. Soil Sci.; 57; 774-786 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the effect of clay mineralogy on the protection of organic matter in soils | ... the ratio of residue-derived over root-derived C decreased in most size fractions over time, indicating a greater potential for longer-term root-C than residue-C stabilisation by aggregates in both soils.; .. all aggregates >53 m had greater residue-C concentrations in the illitic soil than in the kaolinitic soil and this difference increased with increasing aggregate size. This suggested a greater affinity of illite clay than kaolinite clay to bind with fresh residue-derived cpds into larger aggregates and hence a greater importance of aggregates in stabilising residue-C in illitic compared with kaolinitic soils. |
| 1030 | Denef, K., Six, J., Merckx, R. & Paustian, K. | Short-term effects of biological & physical forces on aggregate formation in soils with different clay mineralogy | 2002 | Soil (General) | Journal | Plant Soil; 246; 185-200 | English | Hardcopy:Partial | Lab. expt. to study the effects of nutrient and OM addition, root growth and drying-wetting cycles on macroaggregate formation. Compared to 2:1-claydominated soils, 1:1 soils were less dependent on SOM for macroaggregate formation, showing a lower increase in macroaggregation on OM addition, but, under low OM levels, they had a larger capacity to form macroaggregates. At high OM levels mixed 1:1 and 2:1 soils, which had the highest CEC, showed the greatest macroaggregation and the greatest response to OM inputs. | .. In control treatments i.e. without nutrient or OM addition ..) the formation of .. macroaggregates (>250 m) increased in the order: 2:1 clay soil > mixed clay soil > 1:1 clay soil. |
| 1415 | Denef, K., Six, J., Merckx, R. & Paustian, K. | Carbon sequestration in microaggregates of no-tillage soils with different clay mineralogy | 2004 | Soil (General); Tillage | Journal | Soil Sci. Soc. Am. J.; 68 (6); 1935-1944 | English | Hardcopy:Partial | Lab. expt. to evaluate the contribution of macroaggregate-protected microaggregates in the sequestration of carbon in 3 very different soils under conventional (CT) and zero (NT) tillage | In all three soils total SOC as well as microaggregate-associated C was greater with NT compared with CT. Although less than half of the total SOC under NT was associated with the microaggregate fraction, more than 90% of the total difference in SOC between NT and CT was explained by the difference in microaggregate-associated C in all three soils. |
| 1207 | Denef, K., Six, J., Paustian, K. & Merckx, R. | Importance of macroaggregate dynamics in controlling soil carbon stabilisation: short-term effects of physical disturbances induced by dry-wet cycles | 2001 | Soil Organic Carbon; Soil (General) | Journal | Soil Biol. Biochem.; 33 (15); 2145-2153 | English | Hardcopy:Partial | Expt. to determine the effect of drying and wetting on macroaggregate turnover, microaggregate formation within macroaggregates and aggregate-assoc'd C dynamics | .. POM-C in new microaggregates within macroaggregates is inhibited by an enhanced macroaggregate turnover, which is only in the short term enhanced by drying and wetting. .. besides a release of total (i.e. native and wheatderived) POM upon macroaggregate breakdown, drying and wetting induced a fast reformation of macroaggregates with preferential incorporation of wheat-derived POM, resulting in a relative decline of native POM-C in DW macroaggregates. |
| 973 | Derenne, S. & Knicker, H. | Chemical structure and preservation processes of organic matter in soils and sediments | 2000 | Soil Organic Carbon | Journal | Org. Geochem.; 31; 607-608 | English | Hardcopy:Full; PDF:Full | Review (v. brief) of current state of humus research | Among the various reasons for the stability of OM in soils is the occurrence of black carbon ..; The role of the mineral phase in OM preservation is increasingly considered ..; .. aromatic structures and polysaccharides can be stabilised by organo-mineral associations. |
| 1383 | Derenne, S. & Largeau, C. | A review of some important families of refractory macro-molecules: composition, origin and fate in soils and sediments | 2001 | Lignin and CBW | Journal | Soil Sci.; 166 (11); 833-847 | English | Hardcopy:Partial | Review of lignin and other refractory substances in soil | Lignins are the second most abundant constituent of vascular plants after polysaccharides. They account for 5 to 10% by weight of leaves .. and for up to 30% of wood.; .. lignin exhibits a higher resistance to microbial degradation than cellulose. It is considered an important precursor of humic substances ..; Lignin is quite resistant under anaerobic conditions .. but it can be degraded aerobically by white-rot and brown-rot fungi, the former being more efficient.; The mineral matrix plays an important role in lignin degradation through its control of the microbial availability of OM. |
| 115 | Derpsch, R. [3 pp. only] | Historical review of no-tillage cultivation of crops | 1998 | Tillage | Book | ; Proc. 1st JIRACS Seminar on Soya-bean Research: No-tillage Cultivation and Future Research Needs; | English | Hardcopy:Partial | The development of zero tillage in Europe is described. Figures are given for the area under zero tillage in various countries. For the U.K. the figure in 1983/84 was 275,000 ha and for 'Others' (including the U.K.) in 1996/97, was 460,000 ha. [paper also on the website: www.rolf-derpsch.com/notill] | The invention of the herbicide Paraquat in 1955 in the United Kingdom was the start of modern no-tillage development in Europe and also world-wide. This discovery led .. I.C.I. to initiate research without soil tillage. In 1973/74 the area under no-tillage in Great Britain increased to 200,000 ha and ten years later to 275,000 ha. Thus the U.K. had the second largest area under no-tillage in the world after the U.S.A. |
| 726 | Desjardins, T., Andreux, F., Volkoff, B. & Cerri, C.C. | Organic carbon and 13C contents in soil size-fractions and their changes due to deforestation and pasture installation in eastern Amazonia | 1994 | Soil Organic Carbon | Journal | Geoderma; 61 (1/2); 103-118 | English | Hardcopy:Partial | Expt. to compare the soil under the native evergreen rainforest and the soil from 10-yr-old grassland on @deforested land. The forest soil had a C content of 81 t ha-1. | The decrease in soil C content which was observed after ten years of pasture appeared to be relatively low when compared with the results often reported about the effects of deforestation .. in the tropics.; .. the oldest SOM pool is considered to be present at the same concentration in any layer of the soil (profile. .. the amount of 2.8 mg g-1 in the 100-200 cm layer represents 42 t ha-1. If this amount is regarded as the stable pool and is converted into t ha-1 in each horizon of the 0-100 cm soil layer, it would represent about 45.2 t ha-1, that is, about 59% of the total C. Since the age decreases linearly toward the soil surface, the proportion of the stable C pool also decreases with the increasing proportion of the labile C pool. Thus, in the upper 20 cm layer the stable pool would represent about 26% of the total and the labile one about 74%. Similarly in the upper 10 cm layer the calculation yields 16% and 84% for the stable and labile fractions respectively. |
| 176 | Devendra, C. & Thomas, D. | Crop-animal systems in Asia: importance of livestock and characterisation of agro-ecological zone | 2002 | Stockless Farming | Journal | Agric. Sys.; 71 (1/2); 5-15 | English | Hardcopy:Full | The significance of animals in the agriculture of South and South-east Asia is explained. Although crops and animals are closely integrated in the mixed farming systems, crop production tends to predominate, especially in the irrigated areas. To meet increasing food requirements production of animal products needs to be developed, especially in the rain-fed areas, which already have greater stocks of animals. Animals increase both financial and food security, as well as providing transport, manure and power on the farm. | Animal production is a major component of the agricultural economy in Asia and its importance exceeds food production alone. Often official statistics underestimate the overall contribution of animals, as they ignore the multipurpose role that livestock play in agricultural production.; Livestock convert plant resources of low nutritive value to high quality products such as meat and milk ..; .. livestock are linked closely to the social, cultural and religious lives of millions of resource-poor farmers ..; Between 43 and 88% of the human population in these countries [of South-east Asia] depend on the agricultural sector for their livelihoods. Small-scale resource-poor farmers own about 95% of the livestock.; [in South Asia] agriculture is a major activity contributing 25-43% to the GDP, with animals contributing 10-45% to the agricultural GDP. This proportion is even higher if values for manure and draught power are included.; In Nepal increasing animal populations and uncontrolled utilisation have resulted in overgrazing, soil erosion (up to about 40 t/ha/year) and forest degradation. |
| 1531 | Dexter, A.R. & Bird, N.R.A. | Methods for predicting the optimum and the range of soil water contents for tillage based on the water retention curve | 2001 | Soil (General); Tillage | Journal | Soil Tillage Res.; 57 (4); 203-212 | English | Hardcopy:Partial | Review of published exptal results on soil water contents with a view to developing methods for the prediction of the soil water content at which tillage may satisfactorily be carried out. | Three water contents are considered: the lower (dry) limit, the optimum water content and the upper (wet) limit.; The effects of tillage are considered in relation to some fixed points, including the lower plastic limit, field capacity and a new fixed point 'the inflection point'. |
| 897 | Diamond, J.M. | Human use of world resources | 1987 | Greenhouse Gases; Sustainability | Journal | Nature (Lond.); 328; 479-80 | English | Hardcopy:Full | A review of the work of Vitousek et al. on the human appropriation of the global net primary product. A table is given, showing the ways in which humans use, divert and reduce the product of photosynthesis. | The resulting estimate [from Vitousek's work] is a global NPP of about 225 Pg [of OM per year].; The total NPP that humans command is 42.6 Pg, of which 7.2 Pg are used directly and 35.4 Pg diverted. This represents 19% of the earth's total NPP: 31% of that on land and 2% of that in the sea.; These reductions in NPP [resulting from human activity] by 17.5 Pg are in addition to the 42.6 Pg .. Hence out total appropriation in .. 60.1 Pg .. This appropriation falls more heavily on the terrestrial NPP (17.5 + 40.6 = 58.1, out of a potential terrestrial NPP of 132.1 + 17.5 = 149.6, or 39%) than on marine NPP (2.0/91.6 = 2%). |
| 1532 | Dick, W.A., Blevins, R.L., Frye, W.W., Peters, S.E., Christenson, D.R., Pierce, F.J. & Vitosh, M.L. | Impacts of agricultural management practices on C sequestration in forest- derived soils of the eastern Corn Belt | 1998 | Organic Farming; Soil Organic Carbon; Tillage | Journal | Soil Tillage Res.; 47 (3-4); 235-244 | English | Hardcopy:Full; PDF:Full | Long-term field studies of tillage and rotation effects on SOC | One of the most important agricultural management practices controlling C concentrations and amounts in soil in managed agroecosystems is tillage intensity. Amount of organic C in the 0 to 30 cm soil layer .. was 17 Mg ha-1 greater when continuously managed (i.e. for 30 consecutive years) by NT as compared to plough tillage.; .. SOC concentrations (0 to 25 cm soil layer) in the manured plots .. were higher than in non-manured plots ..; Annual manure input ranged from 22 to 67 Mg ha-1 ..; Annual residue inputs to soil were estimated as 10, 6.0, 3.0, 5.5 and 8.0 Mg ha-1 for corn, sugar beet, navy bean, oat and alfalfa respectively . |
| 1208 | Diels, J., Vanlauwe, B., Sanginga, N., Coolen, E. & Merckx, R. | Temporal variations in plant 13C values and implications for using the 13C technique in long-term soil organic matter studies | 2001 | Soil Organic Carbon | Journal | Soil Biol. Biochem.; 33 (9); 1245-1251 | English | Hardcopy:Partial | Expt. to test the reliablity of the 13C technique in long-term SOM studies | |
| 689 | Diepenbrock, W. | Yield analysis of winter oilseed rape (Brassica napus L.): a review | 2000 | Rape and Biodiesel | Journal | Field Crops Res.; 67 (1); 35-49 | English | Hardcopy:Partial | Review of research into the yield and yield potential of winter oilseed rape | Analysing the yield of winter oilseed rape revealed considerable potential for further improvement of yield. Duration of growth, rate of production and harvest index are crucial for enhancing biomass and seed yield. During the growth cycle, establishment of the stand, flower initiation, use of radiation and availability of assimilates for pod set and seed filling are decisive factors influencing yield. For breeding purposes physiologically based selection criteria should include light absorption, the LAID until flowering, synchronisation of source and sink capacity and average productivity of pods. |
| 340 | Diepeningen, A.D. van, Vos, O.J. de, Korthals, G.W. & Bruggen, A.H.C. van | Effects of organic versus conventional management on chemical and biological parameters in agricultural soils | 2006 | Organic Farming; Soil (General) | Journal | Appl. Soil Ecol.; 31; 120-135 | English | Hardcopy:Partial; PDF:Full | Field expt. to compare soils on organic and conventional farms | The main differences between the two mgmnt types are the significantly lower levels of both nitrate & total soluble N and the larger species richness in both bacteria and nematodes and higher numbers of bacteria in organic soils.; .. organic farmers plough their fields less deeply and tend to apply more OC to their fields, but this did not result in a significantly higher OC content ..; Soil type - clayey or sandy soil - .. had a much stronger effect on the soil characteristics than management type. |
| 727 | Dignac, M.F., Bahri, H., Rumpel, C., Rasse, D.P., Bardoux, G., Balesdent, J., Girardin, C., Chenu, C. & Mariotti, A. | Carbon-13 natural abundance as a tool to study the dynamics of lignin monomers in soil: an appraisal at the Closeaux experimental field (France) | 2005 | Lignin and CBW; Soil Organic Carbon | Journal | Geoderma; 128; 3-17 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the fate of lignin in soil | .. the proportion of newly derived OC after 9 years of maize cropping .. was 9% for total SOM and 47% for lignin, which displayed faster dynamics in this soil than total OC. This study confirms .. that lignin macromolecules are not stabilised as such in these soils. |
| 1719 | Dignac, M.F., Knicker, H. & Kögel-Knabner, I. | Effect of N content and soil texture on the decomposition of organic matter in forest soils as revealed by solid-state CPMAS NMR spectroscopy | 2002 | Uncategorised | Journal | Org. Geochem.; 33; 1715-1726 | English | PDF:Full | ||
| 1019 | Dilkes, N.B., Jones, D.L. & Farrar, J.F. | Temporal dynamics of carbon partitioning and rhizodeposition in wheat | 2004 | Plant C&N Allocation; Roots & Rhizodeposition | Journal | Plant Physiol. (Rockv.); 134; 706-715 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the exudation of recent photosynthate from plant roots | .. exudation [from roots] is maximal 2 to 3 h after fixation in photosynthesis, xthat exudation is, after 20 h, around 3% of the 14C fixed in photosynthesis and that exudation depends more on the rate of carbon import into the root than on the rate of photosynthesis. |
| 880 | Dill, I., Kraepelin, U., Schultze, U., Reh, U. & Weissleder, I. | The role of nitrogen in white- and brown-rot decay: presentation of an ecological model | 1987 | Lignin and CBW | Journal | Les colloques de l'INRA; 40; | English | Hardcopy:Partial; Wordperfect:Full | Lab. expt. to test the hypothesis that white- and brown-rot fungi are able to mobilise N from wood and that N availability in wood is the main cause of lignin degradation by white-rot fungi. Wood normally contains less than 3% of N and about half of that is firmly bound in ligno-protein complexes, so it is not freely available to microorganisms. In the case of n-sensitive white-rot fungi N limitation stimulates preferential or selective ligninolysis, which mobilises lignin-bound N. The consequent fungal growth re-establishes N limitation. | |
| 832 | Dilly, O. | Effects of glucose, cellulose and humic acids on soil microbial eco-physiology | 2004 | Soil Microorganisms | Journal | J. Plant Nutr. Soil Sci.; 167 (3); 261-266 | English | Hardcopy:Partial | 20-day lab. expt. to study the effect of substrate quality on microbial activity | Soil respiration was stimulated by the substrate quality in the order: humic acid < cellulose < glucose .. |
| 1209 | Dilly, O. | Microbial respiratory quotient during basal metabolism and after glucose amendment in soils and litter | 2001 | Soil Microorganisms | Journal | Soil Biol. Biochem.; 33 (1); 117-127 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the relationship between CO2 evolved and O2 consumed by the SMB in various soils | @; The microbial respiratory quotient (RQ), defined as the ratio of mol CO2 evolution per mol O2 uptake, ... was frequently <1 during basal metabolism when no substrate was added. This indicates relatively high O2 consumption during the current microbial |
| 530 | Dilly, O., Blume, H.P., Sehy, U., Jimenez, M. & Munch, J.C. | Variation of stabilised, microbial and biologically active carbon and nitrogen in soil under contrasting land use and agricultural management practices | 2003 | Organic Farming; Soil Organic Carbon; Soil N Dynamics | Journal | Chemosphere; 52; 557-569 | English | Hardcopy:Partial; PDF:Full | Field expt. to compare the C/N ratios of whole soil, microbial biomass and biologically active C & N (measured by the C & N mineralisation rates) in soils from native forest and grassland and from conventional and organic arable land | .. the mineralisation activity rate .. ranged between 0.11 and 17.67 %g CO2-C g-1 soil h-1 & -0.12 and 3.81 %g (dNH4+ + dNO3-)-N g-1 soil h-1. Negative N data may be derived from both N immobilisation & N volatilisation during the expts. The ratio between C & N mineralisation rates differed significantly between the soils, ranging from 5 [?] to 37, and was not correlated with the soil C/N ratio and Cmic/Nmic ratio. The C/N ratio in the biologically active pool was .. smaller in soils under conventional farming than those under organic farming systems.; .. short-term available C & N compounds control N mineralis'n and the current microbial ecophysiology. In agricultural systems soil C/N ratios frequently ranged between 10 and 12, the microbial C/N ratio was lower and C/N ratio in the biologically active pool varied between -15 [?] and 37.; .. microbial C- and N-use efficiency was frequently higher in soils under conventional and precision farming systems than in those under organic farming systems. |
| 797 | Dinesh, R., Suryanarayana, M.A., Nair, A.K. & Ghoshal Chaudhuri, S. | Leguminous cover crop effects on nitrogen mineralisation rates and kinetics in soils | 2001 | Green Manure; Mineralisation; Soil N Dynamics | Journal | J. Agron. Crop Sci.; 187 (3); 161-166 | English | Hardcopy:Partial; Wordperfect:Full | Expt. to study the N mineralisation rate in soil from a 7-year leguminous green manure, which was ploughed in and re-sown every year | The study .. revealed .. high [N] mineralisation rates during the first week .. thereafter they were below detection limits.; As the more labile org. N disappears & the more recalcitrant org. N predominates in the org. N pool, the mineralisation rate would be expected to slow down.; .. the lignin+polyphenol/ N ratio accounted for maximum variation in the rate of N mineralisation from the cover crops incorporated into the soil.; .. lignin reduces the rate of N mineralisation from decomposing plant materials by forming ligno-protein complexes. .. Soluble phenols may precipitate proteins, thereby inhibiting microbial/enzyme activities essential for N mineralisation. |
| 289 | Dobermann, A., Dawe, D., Roetter, R. & Cassman, K.G. | Reversal of rice yield decline in a long-term continuous cropping experiment | 2000 | Miscellaneous; Soil N Dynamics | Journal | Agron. J.; 92; 633-643 | English | Hardcopy:Partial; PDF:Full | Review of results of 35-year field expt. to study the yields of triple-crop rice | From 1968 to 1991 grain yields declined at an annual rate of 1.4-2.0%. From 1991 to 1995, dry-season yields in the highest N treatment increased to within 80 to 100% of the simulated yield potential; yields in the unfertilised control did not increase.; N deficiency caused the yield decline before 1991. |
| 833 | Domanski, G., Kuzyakov, Y., Siniakina, S. & Stahr, K. | Carbon flows in the rhizosphere of ryegrass (Lolium perenne) | 2001 | Plant C&N Allocation; Roots & Rhizodeposition | Journal | J. Plant Nutr. Soil Sci.; 164 (4); 381-387 | English | Hardcopy:Partial | Lab. expt. to study the carbon allocation and soil respiration of ryegrass | 14C in CO2 efflux from soil was detected as early as 30 min after labelling.; The partitioning of assimilated C was completed .. 5 days after assimilation. .. we calculated the amount of assimilated C during 47 days of growth at 256 g C m-2. Of this amount 122 g C m-2 were allocated to below ground, shoots retained 64 g C m-2 and 70 g C m-2 were lost from the shoots due to respiration. Roots were the main sink for belowground C.. they accounted for 74 g C m-2, while 28 g C m-2 `were respired & 19 g C m-2 were found as residual 14C in soil & microorganisms.; [100%, 48%, 25%, 27%, 29%, 11% and 7% of gross assimilated C respectively] |
| 1533 | Domzal, H., Hodara, J., Slowinska-Jurkiewicz, A. & Turski, R. | The effects of agricultural use on the structure and physical properties of three soil types | 1993 | Soil (General); Tillage | Journal | Soil Tillage Res.; 27; 365-382 | English | Hardcopy:Partial | Comparison of the properties of soils from natural forest and from agricultural systems with low and high levels of mechanisation. The agricultural use of forest soils results in an increase in BD and a reduction in water capacity and air permeability. | Full mechanisation of field operations over many years leads to additional increase of compaction .. as well as to further deterioration of the structure and physical properties of soils. This effect is stronger in soil with a small content of humic compounds .. |
| 394 | Donaldson, J.V.G., Hughes, J. & Leake, A.R. | The influence of cropping sequences and rotational management on energy use for machinery operations and crop production | 1996 | Energy in Agriculture; Organic Farming; Tillage | Journal | Aspect. Appl. Biol.; 47; 383–386 | English | Hardcopy:Full | Calculation of energy used for grain production in organic, integrated (reduced tillage) and conventional (plough tillage) farming systems. Average energy use for winter wheat was 72.46, 39.84 and 51.16 kWh/ton | ... the mechanical energy use per hectare is far less under IFS than in crops grown conventionally. This is mainly due to savings ... through non-inversion tillage ...; The organic system at Stoughton compared unfavourable, although there are obviously large savings in outside energy inputs, as no pesticides or mineral fertilisers are used. There are also some savings in machinery energy, but the low level of output, <50% of conventional or IFS regime, means that a lot more machinery energy goes into each ton produced. |
| 395 | Donaldson, J.V.G., Hutcheon, J.A. & Jordan, V.W.L. | Evaluation of energy usage for machinery operations in the development of more environmentally benign farming systems | 1994 | Energy in Agriculture; Organic Farming; Tillage | Journal | Aspect. Appl. Biol.; 40; 87-91 | English | Hardcopy:Full | Calculation of energy use in conventional and integrated cereal production | ... savings in energy have been obtained in less intensive and integrated farming systems that use minimum tillage techniques for crop establishment compared with conventional production systems that are ploughed.; Low input systems for both rotations show considerable reductions in energy inputs over the standard farm practice: 19% on the conventional and 13% on the integrated ... |
| 341 | Donegan, K.K., Palm, C.J., Fieland, V.J., Porteous, L.A., Ganio, L.M., Schaller, D.L., Bucao, L.Q. & Seidler, R.J. | Changes in levels, species and DNA fingerprints of soil microorganisms associated with cotton expressing the Bacillus thuringiensis var. kurstaki endotoxin | 1995 | Miscellaneous | Journal | Appl. Soil Ecol.; 2 (2); 111-124 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the effect of cotton plants, genetically engineered to produce Bacillus thuringinesis var. kurstaki endotoxin, on soil microorganisms | Although the generally transitory stimulation in microbial populations that was observed from the transgenic 247 and 249 cotton plants may not be of environmental concern, the accompanying change in the microbial species composition, with a potential impact on soil processes, may be of ecological significance.; Our results emphasise the importance of performing risk assessment studies for transgenic plants under a variety of environmental conditions. |
| 887 | Donnelly, P.K., Entry, J.A., Crawford, D.L. & Cromack, K. | Cellulose and lignin degradation in forest soils: response to moisture, temperature and acidity | 1990 | Lignin and CBW; Soil Organic Carbon | Journal | Microb. Ecol.; 20; 289-295 | English | Hardcopy:Partial | Expt. to study the factors affecting the rate of degradation of cellulose and lignin. There was a significant correlation between soil moisture, microbial biomass and the rates of cellulose and lignin degradation. | The concentration of lignin in plant tissue is a major factor controlling OM degradation rates in forest ecosystems.; .. cellulose decomposition was substantially higher than lignin decomposition.; Lignin degradation by wood decay fungi is known to be dependent on an additional source of C. As the additional C source is decomposed, both cellulose and lignin degradation rates should decrease. .. formation of humic compounds during decomposition will result in a residual C matrix more resistant to decomposition. |
| 212 | Doran, J.W. | Soil health and global sustainability: translating science into practice | 2002 | Soil (General); Sustainability | Journal | Agric. Ecosyst. Environ.; 88; 119-127 | English | Hardcopy:Full | The case is made for the importance of soil quality/health in the sustainability of agricultural systems and the need for simple indicators of soil quality/health that can be used by farmers to assess the sustainability of their practices. Some proposed indicators are: SOM changes with time, depth of topsoil and rooting, percentage of soil that has a protective cover and soil electrical conductivity as an index of leachable salts like nitrates. | .. SOM serves as a primary indicator of soil quality and health for both scientists and farmers.; Research is needed to help [farmers] assess the sustainability of agricultural management using indicators of soil quality and health to which they have access. |
| 1534 | Doran, J.W., Elliott, E.T. & Paustian, K. | Soil microbial activity, nitrogen cycling and long-term changes in organic carbon pools as related to fallow tillage management | 1998 | Soil Organic Carbon; Soil Microorganisms; Tillage | Journal | Soil Tillage Res.; 49 (1-2); 3-18 | English | Hardcopy:Full; PDF:Full | Long-term study of the microbial, C and N content of two soils (one that was broken from sod immediately before the start of the expt. and the other that had been under cultivation for 30 years) under a wheat-fallow rotation and various tillage treatments. | No-till management resulted in a different environment for biological activity near the soil surface, which was often cooler and wetter than that with conventional tillage .. Consequently biological activity and org. C reserves were also concentrated near the soil surface with no-tillage and there was greater potential for immobilisation of plant available N in organic forms. |
| 728 | Dorioz, J.M., Robert, M. & Chenu, C. | The role of roots, fungi and bacteria on clay particle organisation. An experimental approach | 1993 | Roots & Rhizodeposition; Soil Microorganisms | Journal | Geoderma; 56 (1/4); 179–194 | English | Hardcopy:Partial | Expt. to study the effects of living organisms on the structure of clay. The initiation & stabilis'n of microaggregates was favoured by the secretion of polysaccharides from roots, fungi & bacteria, as well as by mycelia networks entangling the clay and roots and hyphae causing compaction of the clay particles | |
| 213 | Douds, D.D., Galvez, L., Franke-Snyder, M., Reider, C. & Drinkwater, L.E. | Effect of compost addition and crop rotation point upon VAM fungi | 1997 | Compost & Biocontrol; Organic Farming; Soil Microorganisms | Journal | Agric. Ecosyst. Environ.; 65; 257-266 | English | Hardcopy:Partial | An expt. comparing the development of VAM fungus on three plots fertilised solely with conventional fertiliser, raw FYM and compost respectively. The compost was made from animal manure and leaves. The application of compost significantly increased the spore populations of two VAM fungus species groups, but populations of other groups were not affected. If the rate of compost application is calculated on the basis of the N requirement of the crop, other nutrients may be in excess, especially P. As this accumulates in the soil from year to year, it depresses the levels of VAM fungi, as does the inclusion of non-mycorrhizal plants in a rotation (e.g. spinach or peppers). | |
| 214 | Douds, D.D., Galvez, L., Janke, R.R. & Wagoner, P. | Effect of tillage and farming system upon populations and distribution of vesicular-arbuscular mycorrhizal fungi | 1995 | Soil Microorganisms; Tillage | Journal | Agric. Ecosyst. Environ.; 52 (2-3); 111-118 | English | Hardcopy:Partial | Inconclusive expt. in which V.A.M. fungi on maize roots were examined under various treatments ranging from ploughing to zero tillage in both conventional and low-input systems. Populations of some fungal species were higher and others lower under all treatments and in both systems. | |
| 898 | Downie, A. | Fixing a symbiotic circle | 1997 | Green Manure | Journal | Nature (Lond.); 387; 352-354 | English | Hardcopy:Partial; PDF:Full | Review of current research on bacterial plasmids in Rhizobium | ... rhizobia grow slowly for long periods in soil, but, if they infect a compatible legume, they can grow rapidly. Successful infection by a single bacterium can lead to the formation of a nitrogen-fixing nodule on the root of the legume, containing over 108 bacterial progeny. |
| 91 | Drinkwater, L.E. | Using plant species composition to restore soil quality and ecosystem function | 1999 | Green Manure; Organic Farming; Tillage | Book | Olesen, J.E., Eltun, R., Gooding, M.J., Jensen, E.S & Köpke, U. (eds); Designing & testing crop rotations for organic farming. Proceedings from an international workshop; | English | Hardcopy:Partial; Wordperfect:Full | Review of cropping system variations that can improve soil quality | Common short-comings of intensive cropping systems include: insufficient C additions to maintain SOM, the return of only low-quality high-C senescent organic residues to the soil, nutrient inputs that exceed harvested exports, excessive tillage or tillage at a time that exposes soil to wind and water erosion, rotations that include long fallow periods and use of temporal monocultures.; Although organically-managed systems routinely use many practices that are known to build soil fertility while reducing negative environmental impacts, tillage regimes in annual production systems remain intensive.; Small grains .. and legumes tend to promote aggregation to a greater extent than many cash crops. |
| 1031 | Drinkwater, L.E., Janke, R.R. & Rossoni-Longnecker, L. | Effects of tillage intensity on nitrogen dynamics and productivity in legume-based grain systems | 2000 | Green Manure; Organic Farming; Tillage | Journal | Plant Soil; 227 (1/2); 99-113 | English | Hardcopy:Full; PDF:Full | Long-term expt. to compare maize under org. & conv'l mgmt, & various tillage systems in respect of yield, N dynamics & weed control. With ploughing and chiselling similar yields of maize were obtained under org. & conv'l mgmnt. But the org. zero tillage plots did not give yields that were comparable with the conv'l ones. .. maize yields were 80% down. This may have been due to weed competition, as well as to low plant densities of both green manure and maize. | .. there is no doubt that annual legumes can provide adequate N for subsequent cash crops under conv'l tillage. However, the incorp'n of these low C/N residues frequently results in very rapid net release of min. N shortly after incorp'n, when plant uptake is still minimal.; .. large pools of nitrate resulting from rapid net mineralisation of [green manure] residues .. would be susceptible to leaching in years with rainy springs.; .. in green-manured systems without primary tillage, N limitations frequently occur and mineralisation of adequate N for uptake by the cash crop at the appropriate time is a major concern. |
| 545 | Drinkwater, L.E., Letourneau, D.K., Workneh, F., Bruggen, A.H.C. van & Shennan,C. | Fundamental differences between conventional and organic tomato agro-ecosystems in California | 1995 | Organic Farming | Journal | Ecol. Appl.; 5 (4); 1098-1112 | English | Hardcopy:Full | Expt. to compare organic and conventional agricultural systems | .. differences were demonstrated in many soil, plant, disease and diversity indicators, suggesting that the ecological processes determining yields and pest levels in these two management systems are distinct. .. N mineralisation potential and microbial and parasitoid abundance and diversity were higher in org. farms.; .. soil fertility management practices affected C & N dynamics and had cascading effects on plant-pathogen [and possibly plant-herbivore] interactions .. Increased labile C pools resulted in greater microbial activity in org. soils, contributing to root pathogen suppression through mechanisms such as microbial antagonism or competition. .. org. fertility regimes were associated with reduced tissue N levels and decreased susceptibility to root disease .. |
| 899 | Drinkwater, L.E., Wagoner, P. & Sarrantonio, M. | Legume-based cropping systems have reduced carbon and nitrogen losses | 1998 | Green Manure; Organic Farming; Stockless Farming | Journal | Nature (Lond.); 396; 262-265 | English | Hardcopy:Full | A comparison of three systems, fertilised with chemicals, FYM and leguminous green manure respectively, showed significant differences in the rate of accumulation of C and N in the soil over a fifteen-year period. The rate of C accumulation was highest in the animal manure system, about half as high in the legume system and insignificant in the conventional system. The soil N accumulation in the legume and animal manure systems was roughly equal when expressed as a proportion of the surplus of N input over export in each case. Soil N accumulation in the conventional system was negative. | Quantitative differences in net primary productivity and N balance across agroecosystems do not account for the observed changes in soil C and N. .. the use of low-C/N organic residues to maintain soil fertility ..increases the retention of soil C and N, which has important implications for regional and global C and N budgets.; Application of these practices in the major maize/soya bean growing region in the USA would increase soil C sequestration by 0.13 - 0.30 x 1014 g/yr. This is equal to 1-2% of the estimated annual C released into the atmosphere from fossil fuel combustion in the USA. .. The potential effects on the N cycle are much greater .. . |
| 1416 | Drury, C.F., Tan, C.S., Reynolds, W.D., Welacky, T.W., Weaver, S.E., Hamill, A.S. & Vyn, T.J. | Impacts of zone tillage and red clover on corn performance and soil physical quality | 2003 | Green Manure; Tillage | Journal | Soil Sci. Soc. Am. J.; 67 (3); 867-877 | English | Hardcopy:Partial | Expt. to study whether zone tillage could improve yields in comparison with zero tillage on fine-textured soil in cool humid climates. Zone tillage is a modification of zero tillage in which a narrow strip, 10-20 cm wide and 10-30 cm deep, is conventionally tilled in the crop row, leaving the rest of the soil untilled. | .. grain yield was the greatest under the zone-tillage treatment, .. intermediate under the conventional tillage treatments and lowest under the notillage treatments.; The optimal BD for root growth in fine-textured soils is .. 0.8 to 1.2 Mg m-3 and root growth often stops completely in clayey soils at about 1.5 Mg m-3. The [zone tillage] treatment had .. among the lowest BD in each .. year, while the two no-tillage treatments often had the greatest BD.; The air-filled porosities ranged from 0.14 to 0.20 m3 m-3 .. These values are .. near or above the suggested minimum of 0.15 m3 m-3 for adequate near-surface aeration in the root zone of clayey soils.; Saturated hydraulic conductivity values in hthe range 10-2 to 10-5 cm s-1 may provide an optimum between the competing needs for rapid sorption into the soil matrix of needed crop-available water and rapid drainage of excess water that could cause water-logging and associated aeration deficits. |
| 1599 | Duijn, C.M. van, Delasnerie-Lauprêtre, N., Masullo, C., Zerr, I., de Silva, R., Wientjens, D.P., Brandel, J.P., Weber, T., Bonavita, V., Zeidler, M., Alpérovitch, A., Poser, S., Granieri, E., Hofman, A. & Will, R.G. | Case-control study of risk factors of Creutzfeld-Jakob disease in Europe during 1993-95 | 1998 | Miscellaneous | Journal | Lancet; 351(9109); 1081-1085 | English | Hardcopy:Full | A study of the factors increasing the risk of contracting CJD | .. a significant increase in risk of CJD was found for cases exposed to leather products and fertiliser containing hoofs and horns. .. the consumption of brain and raw meat were associated with an increased risk of CJD. No association was found with the consumption of beef, veal, lamb, cheese or milk .. |
| 1093 | Duncan, R.C. | World energy production, population growth and the road to the Olduvai Gorge | 2001 | Energy Resources | Journal | Popul. Environ.; 2 (5); | English | Hardcopy:Full; PDF:Full | Modelling the global human economy (based on a development of Forrester's 1972 World3 model) leads to almost the same results as Forrester's, namely, that industrial civilisation ([arbitrarily ?] defined as having started in 1930) will last just over 100 years and will peak in 2013. Per capita global oil production peaked in 1979. Global oil production, the growth rate of which has been decreasing since 1973, will peak in 2006. The proportion of oil produced by the OPEC nations is increasing and will pass the 50% mark in 2008. The Olduvai Theory asserts that the decline of industrial civilisation will take place in three stages: the slide (1979-2000), started by the decline of global per capita energy production, the slope, started by the end of cheap energy and the outbreak of violence in the Middle East, and the cliff, started by an epidemic of worldwide electricity blackouts, leading to the collapse of C3 (communication, computation and control) and eventually the expiry of the electric power networks. This will cause the decline of global per capita energy production, which, by 2030, will have fallen to 3.32 barrels of oil equivalent per year - the same value that it had in 1930. We are then back in the Dark Ages. | If God made the Earth for human habitation, then He made it for the Stone Age mode of habitation. |
| 267 | Dunin, F.X., Williams, J., Verburg, K. & Keating, B.A. | Can agricultural management emulate natural ecosystems in recharge control in south eastern Australia? | 1999 | Miscellaneous | Journal | Agrofor. Syst.; 45; 343-364 | English | Hardcopy:Partial; Wordperfect:Full | Review of the possibilities of designing agricultural systems that can restore the hydrological balance of natural ecosystems | Many of our current production systems are not ecologically sustainable because they leak water and nutrients which, in turn, may result in waterlogging, salinity and soil acidification.; Woody perennials offer a progressive mining of deep soil water over time to generate buffer sizes that may exceed lucerne by as much as 100 mm at a specific site.; Hydraulic lift is now a widely accepted phenomenon whereby deep soil water is uplifted along the translocation pathway during summer stress to be diverted into shallow roots to maintain turgor and function. |
| 173 | Durham, S. | Plastic mulch; harmful or helpful? | 2003 | Mulch | Journal | Agric. Res.; ; 14-16 | English | Hardcopy:Full | Exptal comparison between plastic mulch and hairy vetch in respect of the amount of pesticide in run-off, which was found to be less with living mulches than with plastic | |
| 8 | Ebertseder, T., Gutser, R. & Claassen, N. | Parameters to estimate the nitrogen effect of biogenic waste composts | 1996 | Compost & Biocontrol; Soil N Dynamics | Book | Bertoldi, M. de, Sequi, P., Lemmes, B., & Papi, T. (eds.); The science of composting; | English | Hardcopy:Full; Wordperfect:Full | Field and lab. expts to assess the effect of compost on nitrogen availability in compost-fertilised soils | @; The ratio of total organic C to total N of composts ... is relatively well correlated with their N effect in soil. However, [it] depends on the raw materials and management of composting. Therefore it cannot be used as the only parameter for calculatin |
| 215 | Edwards, L., Burney, J.R., Richter, G. & MacRae, A.H. | Evaluation of compost and straw mulching on soil-loss characteristics in erosion plots of potatoes in Prince Edward Island, Canada | 2000 | Compost & Biocontrol; Mulch; Tillage | Journal | Agric. Ecosyst. Environ.; 81 (3); 217-222 | English | Hardcopy:Partial; PDF:Full | Field trials were carried out for 3 years, using composted potato waste/ manure/sawdust and a mulch of barley straw in conventional potato growing. Compost application made no difference to soil shear strength, aggregate stability or soil loss. It reduced soil penetration resistance and increased soil moisture by 7% and, on sandy soils, increased potato yield by 7.5 Mg/ha. Mulch did not affect the potato yield or the aggregate stability or penetration resistance of the soil, but it increased soil moisture by 6% and decreased soil loss by 49%. | There seems to be little, arising from this study, to justify the use of compost as a soil amendment.; Spreading compost is tedious because of its bulk and its imposition on the farming schedule.; Not only is it tedious to spread the mulch post-planting, but just how much of it will stay on the surface under windy conditions before plant emergence or hilling is another matter.; .. while it takes reduced tillage to achieve maximum residue-cover effectiveness, for a row crop like potatoes reduced tillage is agronomically inimical to high tuber yields and wide acceptance is, therefore, unlikely. |
| 177 | Edwards-Jones, G. & Howells, O. | The origin & hazards of inputs to crop protection in organic farming systems: are they sustainable? | 2001 | Sustainability | Journal | Agric. Sys.; 67 (1); 31-47 | English | Hardcopy:Partial | Soil Association-approved pesticides and supplementary fertilisers are assessed for sustainability. Despite the high energy costs, the non-renewable inputs and the toxicity of some permitted pesticides and fertilisers, organic farming is probably more sustainable that conventional farming. | .. crop protection activities associated with organic farming are not sustainable in an absolute sense and organic farms are subject to the same class of non-sustainable characteristics as conventional farms. |
| 378 | Eggert, C., Temp, U. & Eriksson, K. | The ligninolytic system of the white rot fungus Pycnoporus cinnabarinus: purification and characterisation of the laccase | 1996 | Lignin and CBW | Journal | Appl. Environ. Microbiol.; 62 (4); 1151-1158 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the secretion of laccase by white-rot fungi, the ligninolytic activity of which is correlated with the secretion of three peroxidases: lignin peroxidase (LiP), manganese peroxidase and laccase | Laccase production by P. chrysosporium seems to be repressed by glucose, .. but laccase activity was detectable when the fungus was grown on cellulose. .. a great number of white rot fungi seem to efficiently degrade wood without the production of LiP .. The mechanism by which lignin is broken down in the absence of LiP, an enzyme with an exceptionally high oxidation potential, remains a mystery.; P. cinnabarinus represents a common type of white rot fungus, devoid of LiP but in possession of laccase in combination with a peroxidase of lower redox potential. Although P. cinnabarinus appears to lack enzymes having the high oxidation potential thought to be necessary for the depolymerisation of the major non-phenolic structures of lignin, it very efficiently degrades the lignin in wood.; Laccase production by P. cinnabarinus was less sensitive to high concentrations of N than is known for production of phenoloxidases in ligninolytic systems of most other white rot fungi. High concentrations of glucose in low-N cultures (C/N ratio 25) led to accumulation of an extracellular polysaccharide which strongly interfered with enzyme extraction from the medium. A similar effect has been demonstrated in P. chrysosporium, in which low-nitrogen high-glucose conditions trigger the synthesis of an extracellular b-1,3-glucan. |
| 33 | Ehaliotis, C. & Giller, K.E. | Nitrogen mineralisation induced by the disturbance of soils from adjacent old pastures and arable fields | 1995 | Mineralisation; Soil N Dynamics; Tillage | Book | Cook, H.F. & Lee, H.C.; Soil Management in Sustainable Agriculture; | English | Hardcopy:Full | Field expt. to compare the amount of N mineralisation resulting from soil disturbance in old pastures with that in adjacent arable fields | The mean amounts of nitrogen mineralised were from two-fold to three-fold greater in the old pastures ...; The difference was attributed to larger amounts of readily available organic substrates being physically protected in the old pasture soils and to greater microbial populations being sustained in old pasture oils, which were partly killed buy disturbance. |
| 1210 | Ehaliotis, C., Cadisch, G. & Giller, K.E. | Substrate amendments can alter microbial dynamics and N availability from maize residues to subsequent crops | 1998 | Soil Microorganisms; Soil N Dynamics | Journal | Soil Biol. Biochem.; 30 (10/11); 1281-1292 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the effect of various amendments (bean residue; 4.4% N, KNO3 and cellulose) on the decomposition of maize (0.35% N) in soil over 5 cropping cycles. The bean residue treatment resulted in a 35% increase in maize-residue N recovery compared with the control, while the KNO3 treatment resulted in a 16% decrease. Cellulose application reduced availability of soil and residue to plants but the effect only lasted for one cropping cycle. Rather than a priming effect, the bean residue showed a pool-substitution effect, in which bean N substituted for maize N in the microbial metabolites being stabilised in the soil. | .. adding high quality plant residues can greatly enhance short- and long-term recovery of N from poor quality residues by plants without exploiting soil N. |
| 568 | Ehrenfeld, J., Parsons, W.F.J., Han, X.G., Parmelee, R.W. & Zhu, W.X. | Live and dead roots in forest soil horizons: contrasting effects on nitrogen dynamics | 1997 | Roots & Rhizodeposition; Soil N Dynamics | Journal | Ecology; 78 (2); 348-362 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the effect of live and dead roots on the rates of ammonification and nitrification in the organic and mineral horizons of a podsol | In mineral soil live roots stimulated ammonification rates but had little effect on extractable N, and the stimulation occurred only if an organic surface horizon was present. In contrast, live roots in organic material reduced both ammonification rates and extractable N. Dead roots increased extractable N in the mineral material, but not the organic material. The presence or absence of an organic horizon had a dominating effect on all aspects of nitrogen dynamics in the mineral soil; not only extractable inorganic N, but also transformation rates, were higher in soils under OM.; Nitrate and nitrification were both extremely low ... In the organic material nitrification accounted for <5% of net mineralisation, but was a larger fraction (up to 70%) of total mineralisation in the mineral soil. |
| 1107 | Ehrlich, P.R. & Kennedy, D. | Millennium assessment of human behaviour | 2005 | Sustainability | Journal | Science; 309; 562-563 | English | Hardcopy:Full; Wordperfect:Full | Proposal for the establishment of an international forum (the MAHB) to discuss the problems of human behaviour as they affect the global ecosystem | A growing scientific consensus says that global society is under increasing threat from the impact of human activities .. Some of these problems require attention from governments and other social institutions. But it is the collective actions of individuals that lie at the heart of the dilemma. Analysis of individual motives and values should be critical to a solution.; The steps that most members of the relevant scientific community believe are necessary (e.g. reduction of .. greenhouse gas emissions, .. limiting human population growth and per capita consumption) are disconnected from those measures the rest of society, and especially politicians, are willing to undertake.; .. the MAHB courts criticism for naivety. |
| 888 | Eiland, F., Klamer, M., Lind. A.M. & Bååth, E. | Influence of initial C/N ratio on chemical and microbial composition during long-term composting of straw | 2001 | Compost & Biocontrol | Journal | Microb. Ecol.; 41 (3); 272-280 | English | Hardcopy:Partial; PDF:Full | 1-year expt. to study the effect of C/N ratio on the composting of Miscanthus straw with varying amounts of added pig slurry. After 3 months the high-C/N lots showed a lesser degree of cellulose degradation (10-20%) than the low-C/N lots (40-69%), but after 12 months their microbial biomass and respiration rates were relatively high compared with the low-C/N lots and they had a higher F/B This could be because the low-C/N lots, which generated more heat in the initial stages of the composting, quickly exhausted the easily available carbon, which was therefore lacking at the stage of re-colonisation of the heap by fungi. | Lignin was not degraded in any of the treatments.; .. samples taken after 6 months .. were suitable for plant growth .. [hence] all composts were mature |
| 963 | Ekblad, A., Nyberg, G. & Högberg, P. | 13C-discrimination during microbial respiration of added C3-, C4- and 13C-labelled sugars to a C3-forest soil | 2002 | Roots & Rhizodeposition; Soil Microorganisms | Journal | Oecologia; 131; 245-249 | English | Hardcopy:Full; PDF:Full | Field expt. to test whether 13C-discrimin'n takes place during microbial respir'n | x; .. our results confirm that any 13C-discrimin'n during microbial respiration of @glucose & sucrose is minor. This implies that 13C-discrimin'n due to factors such as isotopic exchange during CO2-diffusion in the soil atmosphere is also minor. |
| 1535 | Ekeberg, E. & Riley, H.C.F | Effects of mouldboard ploughing and direct planting on yield and nutrient uptake of potatoes in Norway | 1996 | Potato Growing; Tillage | Journal | Soil Tillage Res.; 39; 131-142 | English | Hardcopy:Partial | Field expt. to test the effects of zero tillage on potato yield. Potatoes were planted directly into barley stubble and ridged. | .. the same .. quality was achieved with no tillage ..; The nutrient uptake of the plants was increased by direct planting.; The yield curve to direct planting was steeper, crossing that of conventional tillage on approx. 10 September, thus predicting higher tuber yield for direct planting when harvesting occurred after this date .. |
| 774 | Ekman, S. | Tillage system selection: a mathematical programming model incorporating weather variability | 2000 | Tillage | Journal | J. Agr. Eng. Res.; 77 (3); 267-276 | English | Hardcopy:Partial | A farm-level mathematical programming model to analyse the economics of alternative tillage and cropping systems. The modelling technique used is discrete stochastic sequential programming. | .. a tillage system characterised by lower capital and labour requirements may be as profitable as a conventional system despite lower crop yields. |
| 729 | Ekschmitt, K., Liu, M.Q., Vetter, S., Fox, O. & Wolters, V. | Strategies used by soil biota to overcome soil organic matter stability - why is dead organic matter left over in the soil? | 2005 | Soil Organic Carbon; Soil Microorganisms | Journal | Geoderma; 128; 167-176 | English | Hardcopy:Full; PDF:Full | Review of factors determining the accessibility of SOM to microbial decomposers | .. we classify OM pools [into] passive v. active stabilisation & partial v. absolute refuge... in temperate soils a dominant quantity of org. material resides in the passive stabilisation/partial refuge status & persists in spite of being accessible & decomposable. .. SOM is stabilised by a complex of mechanisms that constrain decompos'n rates, several of which are not based on substrate quality or soil conditions, but on the biology of the decomposing soil organisms. |
| 342 | Elfstrand, S., Båth, B. & Mårtensson, A. | Influence of various forms of green manure amendment on soil microbial community composition, enzyme activity and nutrient levels in leek | 2007 | Green Manure; Soil Microorganisms | Journal | Appl. Soil Ecol.; 36; 70-82 | English | Hardcopy:Partial; PDF:Full | Field expt. to study how soil microorganisms and the activity of soil enzymes are influenced by different forms of green manure amendment (fresh or composted, incorporated or mulched) | .. fresh red clover residues, especially direct incorporation of a red clover crop, enhanced microbial biomass and soil enzyme activities more than processed green manure forms.; An initial increase in abundance of bacteria and fungi was observed after direct incorporation and amendment with red clover-derived slurry and compost, but amendment with fresh red clover sustained a higher bacterial and fungal biomass until the end of the cropping season. Mulching stimulated arbuscular mycorrhizal (AM) fungi at the end of the cropping season. |
| 1650 | Ellen, R. | Environment, Subsistence and System - the Ecology of Small-scale Social Formations | 1982 | Agricultural Ecology | Book | Ellen, R.; Environment, Subsistence and System - the Ecology of Small-scale Social Formations; 130-153 | English | Hardcopy:Full | Various mainly primitive societies are compared in respect of their food production and energy consumption | .. the functioning of culture as a whole rested on, and was determined by, the amount of energy produced and the ways in which it was put to work.; The total amount of energy produced by a population consists of the food yield and the calorific equivalent of other things produced or appropriated, such as crops produced for export and consumed as fuel.; .. total ecological effort .. must strictly speaking include all energy expended by a population.; A standard measure of efficiency is energy production divided by total human energy expenditure.; We are accustomed to associating economic development and cultural evolution with an increase in productive efficiency, but this is only the case if measured solely in terms of human energy expenditure.; .. efficiency is not to be measured in energy ratios alone. .. Nuaulu hunting .. provides a negative calorie return. The importance of the activity lies not in calories but in the provision of high-quality protein and nutrients .. |
| 513 | Ellert, B.H. & Bettany, J.R. | Calculations of organic matter and nutrients stored in soils under contrasting management regimes | 1995 | Soil Organic Carbon; Tillage | Journal | Can. J. Soil Sci.; 75 (4); 529-538 | English | Hardcopy:Partial | Expt. to study the effects of different crops (wheat and maize) and tillage (ploughed and zero tillage) on the storage of C and nutrients in the soil. Attention is drawn to the unreliability of figures for element (C, N, etc.) concentrations in the soil that do not take account of the varying BD of the soil. Examples are given from a paper by Doran. | .. ca. 15% of SOC originally present under forest vegetation was lost after 80 yr of annual cropping. |
| 1384 | Ellert, B.H. & Gregorich, E.G. | Storage of carbon, nitrogen and phosphorus in cultivated and adjacent forested soils of Ontario | 1996 | Phosphorus Cycling; Soil Organic Carbon; Soil (General) | Journal | Soil Sci.; 161 (9); 587-603 | English | Hardcopy:Partial | Field study of 15 arable sites and adjacent forest sites to compare their C, N and P stocks. On average the surface layer of the cultivated soils had 34% less C, 19% less N and 24% more P than the adjacent forest soils. Increase in P storage and narrowing of C/N ratios (12.4 against 16.2) in cultivated oils was a result of fertilisation. | .. from Eastern Qu)bec .. 30 to 35% of C originally present in the A and B horizons of native soils was lost after cultivation for 30 years or more .. soil C under perennial grasses was similar to or greater than that originally present under native forest vegetation. |
| 514 | Elliot, J.A. & Efetha, A.A. | Influence of tillage and cropping system on soil organic matter, structure and infiltration in a rolling landscape | 1999 | Tillage | Journal | Can. J. Soil Sci.; 79(3); 457–463 | English | Hardcopy:Partial | A comparison of a continuously cropped zero tilled field (ZTCC) with a conventionally tilled field under a crop-summer fallow rotation (CTCF). Soil quality was better in many respects on the ZTCC field than on the CTCF. | SOC, aggregate size and aggregate stability were significantly greater on the ZTCC plot than the CTCF.; [There was] substantially more run-off from the CTCF plot than the ZTCC.; As a consequence the CTCF plot is more susceptible to wind and water erosion and has lower inherent fertility than the ZTCC plot. |
| 1417 | Elliott, E.T. | Aggregate structure and carbon, nitrogen and phosphorus in native and cultivated soils | 1986 | Soil Organic Carbon; Soil (General) | Journal | Soil Sci. Soc. Am. J.; 50 (3); 627-633 | English | Hardcopy:Partial | An expt. to examine the stability of soil aggregates and properties of occluded OM | The structure of soil protects SOM & influences OM turnover & soil fertility.; three types of physical units .. exist in mineral soil: free primary particles (i.e. sand, silt & clay), microaggregates & macroaggregates. .. three types of cementing agents [are] responsible for soil aggregation: (i) transient, composed of microbial- and plant-derived polysaccharides, which are rapidly decomposed by microbes; (ii) temporary, including roots and hyphae, especially mycorrhizal, and (iii) persistent: aromatic humic material in association with amorphous Fe & Al compounds.. Persistent binding agents are .. mainly responsible for microaggregates, which range in size from 50 to 250 m [and which] can become united to form macroaggregates through the action of temporary and transient binding agents and are generally 250 m to 2 mm in size.; The loss of OM resulting from cultivation comes chiefly from the organic material that binds individual microaggregates into macroaggregates, not from OM within microaggregates, a high proportion [of which is] more highly processed, humified old, passive or recalcitrant fractions.; There was more OM associated with macroaggregates and it was more labile than that associated with microaggregates. |
| 1676 | Ellis, F. | Peasant Economics: Farm Households in Agrarian Development | 1988 | Agricultural Ecology | Book | Ellis, F.; Peasant Economics: Farm Households in Agrarian Development; | English | Hardcopy:Partial | farming systems of various types are examined from an economic viewpoint | |
| 92 | Eltun, R. & Nordheim, O. | Yield results during the first eight years crop rotation of the Apelsvoll cropping system experiment | 1999 | Organic Farming | Book | Olesen, J.E., Eltun, R., Gooding, M.J., Jensen, E.S & Köpke, U. (eds); Designing & testing crop rotations for organic farming. Proceedings from an international workshop; | English | Hardcopy:Partial; Wordperfect:Full | 8-year field expt. to compare organic and conventional farming systems | The average grain yields of barley in the [organic] systems .. were .. 67% of the [conv'l] system .. Wheat grain yields showed an even greater yield reduction than barley with ecological as compared to conv'l cropping, while a mixture of oats & peas gave higher yield than barley in ecological cropping. The grain protein content & grain size in ecologically grown wheat were lower than in conventionally grown wheat. For potatoes, root and forage crops the yield reduction incurred by .. ecological cropping was smaller than for cereals .. a change from conv'l to .. ecological cropping is easier to achieve in mixed farming systems with livestock than in arable farming systems without livestock. |
| 216 | Eltun, R., Korsaeth, A. & Nordheim, O. | A comparison of environmental, soil fertility, yield and economical effects in six cropping systems based on an 8-year experiment in Norway | 2002 | Organic Farming; Sustainability | Journal | Agric. Ecosyst. Environ.; 90; 155-168 | English | Hardcopy:Partial; PDF:Full | Comparison of conventional, integrated and organic arable and livestock farms (CON-A & -F, INT-A & -F, ECO-A & -F) in an 8-year expt.. On the arable farms the organic cereal and potato yields were 65% and 85% of the conventional yields respectively. | On the basis of nutrient run-off, soil erosion and pesticide contamination, the following ranking from the most to the least favourable was made for environmental effects: INT-F > ECO-F > ECO-A > INT-A > CON-F > CON-A.; .. biological activity seems to be a key explanation of the fact that ecological farming is easier to achieve in a mixed farming system than in an arable one.; Under most Norwegian growing conditions the nutrient mineralisation early in the growing season is limited resulting in insufficient nutrient supply in ecological cereal cropping; .. the yields in ecological farming will stabilise at a significantly lower level than the yields obtained formerly with conventional farming. |
| 1685 | Engle, T.E., Ames, D.R. & Enns, M. | Stress factors of farm animals and their effects on performance | 2002 | Greenhouse Gases | Website | www.colostate.edu/depts/aes (Colorado State University) | English | Hardcopy:Partial | An assessment, based on figures from the literature, of greenhouse gas emissions from cattle farms (beef and dairy). Enteric and manure CH4 emissions from dairy xcows are about 3500 and 1800 kg CO2 equiv. per year per cow respectively. Manure @CH4 emission could be as high as 2600 kg CO2 equiv. per year per cow if anaerobic slurry tanks are used. Total GHG emissions from beef cattle units average 4140 kg CO2 equiv. per cow over the lifetime of the animal (say, 2 years). Of this 50% is CH4 and 40% is N2O. | .. calves .. weighing approximately 230 kg .. fed .. for 56 days or until they reach an approximate weight of 360 kg.; The GHG emissions to produce milk .. are estimated at 1590 g of CO2 equivalent per kg of milk. Enterically produced CH4 is 33% and manure CH4 17% of this total, leaving 50% from other sources, e.g. fertiliser, fuel, soil-C, etc. .. best management practices for crop production could reduce the total by an estimated 14% through increased soil-C sequestration. |
| 1211 | Enwall, K., Nyberg, K., Bertilsson, S., Cederlund, H., Stenström, J. & Hallin,S. | Long-term impact of fertilisation on activity and composition of bacterial communities and metabolic guilds in agricultural soil | 2007 | Organic Farming; Soil Microorganisms | Journal | Soil Biol. Biochem.; 39; 106-115 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the effect of different fertilisers on soil microorganisms | The fertilisation regimes had clear effects on both activity and composition of the soil communities. Basal respiration and r, which was kinetically derived as the exponentially growing fraction of the SIR-response, correlated well with the SOC content. Soil pH ... was found to be an important factor influencing all `microbial activities. pH correlated negatively with the [qCO2], indicating a decreased efficiency of heterotrophic microorganisms to convert org. C into microbial biomass in the most acid soils with pH 3.97 & 4.68 ((NH4)2SO4 & sewage sludge fertilised plots respectively).; The F/B biomass ratio has been suggested to affect the qCO2 and an increasing F/B ratio with decreasing pH has been H observed .. We found a clear correlation between the F/B ratio ... and the qCO2 measured in our study. ... a switch towards a more fungal-dominated microbial biomass could constitute part of the observed effect of pH on the qCO2. |
| 569 | Epstein, H.E., Lauenroth, W.K., Burke, I.C. & Coffin, D.P. | Productivity patterns of C3 and C4 functional types in the U.S. Great Plains | 1997 | Plant C&N Allocation; Miscellaneous | Journal | Ecology; 78 (3); 722-731 | English | Hardcopy:Partial | Study of the climatic and soil factors determining the ranges of C3 and C4 grasses in the U.S.A. 67-85% of the variation in relative and absolute production of C3 and C4 grasses could be explained by temperature, precipitation and soil texture. Production of C4 grasses was positively related to temperature, precipitation and soil sand content and negatively to clay content. Relative production of C3 reaches zero in the range from 17.5$C at 40 cm to 12$C at 110 cm mean annual temperature and precipitation respectively. Relative production of C4 grasses does not reach zero within the U.S.A. (but does in Canada, close to the boundary between grassland and boreal forest). | |
| 126 | Eriksen, J., Askegaard, M. & Vinther, F.P. | Nitrogen cycling in an organic dairy crop rotation: effects of organic manure type and livestock density | 1996 | Soil N Dynamics | Book | Raupp, J. (ed.); Symbiotic nitrogen fixation in crop rotations with manure fertilisation, Proc. 3rd mtg (concerted action AIR3-CT94-1940); | English | Hardcopy:Partial; Wordperfect:Full | Field expt. to measure the N flows on an organic dairy farm | @; Nitrate leaching ranged from 12 to 100 kg ha-1 and was highest in the first years after ploughing-in the grass-clover pasture .. N balances not including atmospheric N fixation showed a deficit in legume-containing crops... it was estimated that this d |
| 1418 | Eswaran, H., Berg, E. van den & Reich, P. | Organic carbon in soils of the world | 1993 | Greenhouse Gases; Soil Organic Carbon | Journal | Soil Sci. Soc. Am. J.; 57 (1); 192-194 | English | Hardcopy:Full | An estimate of the total weight of organic C in the world's soils. Other figures are quoted to give a breakdown of the global reserves of C: vegetation - 550 Pg C, soil - 1500, atmosphere - 750, oceans - 38,000, fossil fuels - 4000, giving a total of 44,800 Pg C. | Globally 1576 Pg of C is stored in soils, with 506 Pg (32%) of this in soils in the tropics. .. 40% of the C in the soils of the tropics is in forest soils. .. deforestation can result in 20 to 50% loss of this stored C, largely through erosion. |
| 1536 | Etana, A., Håkansson, I., Zagal, E. & Bucas, S. | Effects of tillage depth on organic carbon content and physical properties in five Swedish soils | 1999 | Soil Organic Carbon; Tillage | Journal | Soil Tillage Res.; 52 (3-4); 129-139 | English | Hardcopy:Partial; PDF:Full | Study of the effect on the SOC content under different depths of mouldboard ploughing in five long-term tillage expts. | Increased depth of primary tillage reduced the concentration of SOM in the tilled layer .. Within the range of tillage depths studied (12-29 cm) the depth in itself did not affect the total content of organic C in the soil. .. Tillage depth did not affect the C/N ratio. |
| 974 | Eusterhues, K., Rumpel, C., Kleber, M., Kögel-Knabner, I. | Stabilisation of soil organic matter by interactions with minerals as revealed by mineral dissolution and oxidative degradation | 2003 | Soil Organic Carbon | Journal | Org. Geochem.; 34 (12); 1591-1600 | English | Hardcopy:Full; PDF:Full | Chemical treatment of soils to determine the amount and concentration of stabilised OM | @; .. soil samples were exposed to oxidation with Na2S2O8 .. young C is removed preferentially by this treatment. The fraction remaining after oxidation represents a certain stabilised long-residence-time C pool. [which] comprises between 1 and 30% of the |
| 858 | Eve, M.D., Sperow, M., Howerton, K., Paustian, K. & Follett, R.F. | Predicted impact of management changes on soil carbon storage for each cropland region of the conterminous United States | 2002 | Greenhouse Gases; Tillage | Journal | J. Soil Water Conserv.; 57 (4); 196-204 | English | Hardcopy:Partial | Estimating the effect on soil C storage of various changes in agricultural practices, including adoption of zero tillage, increased crop residue inputs, eliminating bare fallow, putting into set-aside and conversion to permanent grassland. Averaged over all regions of the U.S. the estimated rate of soil C accumulation was 1.141, 0.462, 0.325, 0.325 and 0.678 Mg C ha-1 yr-1 for conversion to permanent grassland, putting into set-aside, increasing crop residue input, adoption of zero tillage and a combination of increasing residue input and zero tillage respectively. | The IPCC method uses a tillage factor to account for the effects of tillage management on agricultural soils. The use of no-till is assumed to increase soil C by 10% (a tillage factor of 1.1) over conventional tillage systems ..; Through intensive cultiv'n for crop production 30% to 70% of the soil C that occurred in these soils under native veg'n has been lost to the atmosphere. |
| 268 | Ewel, J.J. | Natural systems as models for the design of sustainable systems of land use | 1999 | Sustainability | Journal | Agrofor. Syst.; 45 (1/3); 1-21 | English | Hardcopy:Partial; PDF:Full | Review of reasons for using natural ecosystems as models for the design of sustainable agriculture to mimic nature | Natural ecosystems, whose components are the results of natural selection, are sustainable .. Thus, they are appropriate models on which to base the design of new systems of land use.; .. it pays to imitate natural systems rather than struggle to impose simplicity on ecosystems that are inherently complex. The keys to success are to (i) channel productivity into outputs of nutritional and economic importance, (ii) maintain adequate diversity to compensate for losses in a system simple enough to be horticulturally manageable, (iii) manage plants and herbivores to facilitate associational resistance and not associational susceptibility and (iv) use perennial plants to maintain soil fertility, guard against erosion and make full use of resources.; .. much high-yield agriculture is not sustainable because its practice consumes non-renewable environmental capital, especially soil and ancient groundwater. .. Native ecosystems are timeproven survivors and it is logical to learn from them and imitate their useful traits. .. [they] are long-term products of evolution and the accommodation of organisms to environment: they change with time, as both environment and biota change, and they run on solar power, thus making them self-sustaining. |
| 9 | Ezelin, K., Brun, G., Kaemmerer, M. & Revel, J.C. | Glucose influence on the asymbiotic nitrogen fixation during lignocellulosic waste composting | 1996 | Compost & Biocontrol; Soil N Dynamics | Book | Bertoldi, M. de, Sequi, P., Lemmes, B., & Papi, T. (eds.); The science of composting; | English | Hardcopy:Partial; Wordperfect:Full | Lab. expt. to study the effect of addition of glucose on nitrogen fixation during the composting of woody waste | The main limiting factor [to N-fixing] was then the absence of C sources adapted to the requirements of the various microbial populations ... an easily degradable compound such as glucose promotes the activity of the N2-fixers, which `include also cellulolytic microorganisms.; .. without glucose no N2-fixation phase was observed.; .. no effect of phosphorus deficiency was observed in the free-living N2-fixers. |
| 1108 | Falkowski, P., Scholes, R.J., Boyle, E., Canadell, J., Caneld, D., Elser, J., Gruber, N., Hibbard, K., Högberg, P., Linder, S., Mackenzie, F.T., Moore III, B., Pedersen, T., Rosenthal, Y., Seitzinger, S., Smetacek, V. & Steffen, W. | The global carbon cycle: a test of our knowledge of earth as a system | 2000 | Greenhouse Gases; Soil Organic Carbon | Journal | Science; 290; 291-296 | English | Hardcopy:Partial; PDF:Full | Review of the mechanisms of the oceanic and terrestrial C cycles | x; Terrestrial net primary production is not saturated by present atmospheric CO2 @concentrations. Consequently, as atmospheric CO2 increases, terrestrial plants are a potential sink for anthropogenic carbon. The principal carbon-fixing enzyme in plants is ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco). In C3 plants the activity of rubisco increases with increasing CO2 concentrations, `saturating between 800 and 1000 ppmv CO2, a concentration that will probably be reached early in the next century at the present emissions rate.; ... increased temperature will probably lead to higher microbial heterotrophic respiration, which may counteract and even exceed the enhancement of NPP.; ... the feedbacks between C and other biogeochemical & climatological processes will lead to weakened sink strengths in the foreseeable future and the prospects of retrieving anthropogenic CO2 from the atmosphere by enhancing natural sinks are small. |
| 457 | Falloon, P.D. & Smith, P. | Modelling refractory soil organic matter | 2000 | Soil Organic Carbon | Journal | Biol. Fertil. Soils; 30 (5-6); 388-398 | English | Hardcopy:Full; PDF:Full | Review of current SOM models, particularly in relation to recalcitrant fractions. Estimates of their size and age from various authors average 2500 years and 30% of total SOC. | Most models for the turnover of SOM include a compartment that is either considered inert or has a very slow turnover time (refractory SOM).; True IOM [inert OM] is not biologically decomposable and therefore has no decomposition rate. .. IOM is a pool uncoupled from the other SOM pools and is effectively a constant. .. IOM remains unaffected by changes in climate, land use or management and, whilst its size is of importance, it cannot, by definition, act as a sink for atmospheric CO2.; A wide range of compounds (e.g. acid-hydrolysis residues, humin, humic acids, and interlayer organic complexes) .. have been identified as highly resistant components of SOM ..; .. attempts to relate physical and chemical fractionations to SOM model pools have had mixed success. Problems related to fractionation of SOM are illustrated by the .. light fraction OM [which] is generally considered labile, but may include charcoal (which is considered refractory), due to its low density. |
| 1212 | Falloon, P.D., Smith, P., Coleman, K. & Marshall, S. | Estimating the size of the inert organic matter pool from total soil organic carbon content for use in the Rothamsted carbon model | 1998 | Soil Organic Carbon | Journal | Soil Biol. Biochem.; 30 (8/9); 1207-1211 | English | Hardcopy:Full; PDF:Full | Estimating the quantity of inert OM (IOM) in soils on the basis of data from 28 long-term expt'l sites. The average IOM content was 6.4 t C/ha (4.2 and 9.4 for arable & forest soils respectively). The average age and size of the recalcitrant fraction from figures reported in the literature was 2400 years and 30% of total SOC. | In RothC IOM represents a small, stable and biologically inert fraction of soil C, which has a high radiocarbon age .. of more than 50,000 yr.; Chemically it is .. a mixture .. of charcoal .., coal and OM trapped irreversibly in the soil.; It may be that a substantial part of IOM is not truly inert, but of a very great turnover time. |
| 1213 | Fang, C. & Moncrieff, J.B. | The dependence of soil CO2 efflux on temperature | 2001 | Soil Microorganisms | Journal | Soil Biol. Biochem.; 33 (2); 155-165 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the temperature & moisture dependence of soil respiration | .. soils showed an exponential increase in respiration rate with temp. No optimal temp for soil respiration was found with soil temp up to 32$C. The influence of soil moisture content .. was not obvious. |
| 1109 | Fang, J., Chen, A., Peng, C., Zhao, S. & Ci, L. | Changes in forest biomass carbon storage in China between 1949 and 1998 | 2001 | Energy Resources; Greenhouse Gases | Journal | Science; 292; 2320-2322 | English | Hardcopy:Full | Estimating the C storage in Chinese forests. The C content of tree biomass is taken as 50%. A formula is given for the conversion of volume of timber to biomass. The C density of natural forests averaged 48 Mg/ha. That of planted forest increased from 15 to 31 Mg/ha in about 20-25 yrs. | |
| 546 | Fang, J., Wang, G.G., Liu, G. & Xu, S. | Forest biomass of China: an estimate based on the biomass-volume relationship | 1998 | Energy Resources; Greenhouse Gases | Journal | Ecol. Appl.; 8 (4); 1084-1091 | English | Hardcopy:Full | Estimating the total (above- and belowground) biomass of China's forest. A C content in the biomass of 50% was assumed. The ratio of aboveground to belowground biomass averaged 4.6, ranging from 2.9 for oak to 7.5 for eucalyptus @plantation. The density of timber averaged 0.9 Mg/cm3. The average area-weighted biomass density was 84 Mg/ha, including 91 and 145 Mg/ha for oak and tropical forest respectively. The corresponding average figures for Europe and the U.S.A. were 64 and 122 Mg/ha respectively. | |
| 934 | Farrar, J.F. & Jones, D.L. | The control of carbon acquisition by roots | 2000 | Plant C&N Allocation; Roots & Rhizodeposition | Journal | New Phytol.; 147 (1); 43-53 | English | Hardcopy:Full; PDF:Full | Review of factors controlling the transport of carbon from shoot to root | The .. hypothesis that acquisition of C by roots is controlled by a range of variables distributed between root & shoot accords with both expt. & theory .. 2 levels of mechanistic control, short-term regul'n of phloem transport & control of gene-expression by cpds such as sugars, underlie distributed control. |
| 570 | Farrar, J.F., Hawes, M., Jones, D.L. & Lindow, S. | How roots control the flux of carbon to the rhizosphere | 2003 | Plant C&N Allocation; Roots & Rhizodeposition | Journal | Ecology; 84 (4); 827-837 | English | Hardcopy:Full; PDF:Full | Review of the factors controlling the flow of C from the roots into the soil | Roots lose metabolites & signal molecules to the soil at rates of significance to soil organisms ..; .. carbon flow to the rhizosphere is a function of root growth. .. the control over the rate at which roots grow is shared between root and shoot, with most control being in the shoot. |
| 217 | Feber, R.E., Firbank, L.G., Johnson, P.J. & MacDonald, D.W. | The effects of organic farming on pest and non-pest butterfly abundance | 1997 | Miscellaneous; Organic Farming | Journal | Agric. Ecosyst. Environ.; 64 (2); 133-139 | English | Hardcopy:Partial | Field expt. to compare the abundance of butterflies on organic and conventional farms | ... more non-pest butterflies were recorded on organic than on conventional farmland ... more non-[pest butterflies were recorded over the uncropped boundary habitat than over the crop edge habitat in both systems ... there was no significant difference ... in the abundance of two pest species ... between the two systems. |
| 730 | Feller, C. & Beare, M.H. | Physical control of soil organic matter dynamics in the tropics | 1997 | Soil Organic Carbon | Journal | Geoderma; 79; 69-116 | English | Hardcopy:Partial | Review of the literature on OM dynamics in tropical soils | Three primary groups of tropical soils can be distinguished, based on mineralogy: (1) kaolinitic/halloyistic or low-activity clay soils .. , (2) smectitic or high-activity clay soils .. , and (3) more or less allophanic soils .. with large amounts of amorphous or crypto-crystalline minerals.; .. in tropical soils .. 20-40% of the SOC is associated with the sand-size (POM) fraction as compared with 2-14% for many temperate examples.; .. greater than 50% of SOC associated with the clay fraction and derived from native vegetation may be lost after clearing and cultivation over a period of 10-20 years. |
| 343 | Feng, G., Song, Y.C., Li, X.L. & Christie, P. | Contribution of arbuscular mycorrhizal fungi to utilisation of organic sources of phosphorus by red clover in a calcareous soil | 2003 | Phosphorus Cycling; Soil Microorganisms | Journal | Appl. Soil Ecol.; 22 (2); 139-148 | English | Hardcopy:Partial | The results of an expt. to test the P uptake of plants with and without AM fungi when the soil outside the root zone was treated with one inorganic and three different inorganic sources of P. Non-mycorrhizal plants showed no difference between the four P sources, but mycorrhizal plants did differ. | At the third harvest, the contribution from KH2PO4 was 23%, while those from lecithin, RNA and sodium phytate [organic sources] were 23, 17 and 31%, respectively. |
| 1214 | Fierer, N. & Schimel, J.P. | Effects of drying-re-wetting frequency on soil carbon and nitrogen transformations | 2002 | Soil Microorganisms; Soil (General) | Journal | Soil Biol. Biochem.; 34 (6); 777-787 | English | Hardcopy:Partial | Expt. to test the effect of wetting and re-wetting on soil microbial communities in soils taken from oak forest and annual grassland | @; Exposure to frequent drying-re-wetting events decreased the amount of CO2 released upon re-wetting and dramatically increased the activity of autotrophic nitrifier populations. For up to 6 weeks after the last drying-re-wetting cycle, respiration rates |
| 218 | Filip, Z. | International approach to assessing soil quality by ecologically related biological parameters | 2002 | Soil (General) | Journal | Agric. Ecosyst. Environ.; 88; 169-174 | English | Hardcopy:Full | A summary of results of a project to test an approach to assessing soil quality, using biol. & biochem. criteria. The sensitivity of some criteria to anthropogenic effects on the soil was tested. The population of N-fixing bacteria, dehydrogenase activity & the processes of nitrification/denitrification & respiration (CO2 release) were found to be the most sensitive. A catalogue of soil organisms and their ecologically important activities is presented. | Soil quality is understood as an integral value of compositional structures and natural functions of soil in relation to soil use & environmental conditions .. |
| 834 | Filip, Z., Pecher, W. & Berthelin, J. | Microbial utilisation and transformation of humic acids extracted from different soils | 1999 | Soil Organic Carbon; Soil Microorganisms | Journal | J. Plant Nutr. Soil Sci.; 162 (2); 215-222 | English | Hardcopy:Partial | Lab. expt. to study the consumption of humic acid (HA) by aerobic cultures of soil microorganisms | .. between 14% & 86% of the added HA was utilised. The formation of microbial biomass was enhanced up to 6-fold in the full-strength nutrient media supplemented with HA, but was strongly inhibited if HA served as the sole C source. HA preparations re-isolated from the microbial cultures exhibited elemental and structural changes characteristic of early diagenetic transformations of humic substances. These included an increase in carbon content, C/N ratio and infrared absorption typical of aromatics and a decrease in infra-red absorption associated with aliphatic acids, nitrogenous and carbohydrate-like substances. |
| 1032 | Filser, J., Fromm, H., Nagel, R.F. & Winter, K. | Effects of previous intensive agricultural management on microorganisms and the biodiversity of soil fauna | 1995 | Soil Microorganisms | Journal | Plant Soil; 170 (1); 123-129 | English | Hardcopy:Partial | Field expt. to compare two plots under cereal crops, one of which had been under rotation and the other under a monoculture of hops, which involved spraying with copper. Populations of meso- and microfauna and of microorganisms were much lower in the hop field than in the rotation one in the first year of cereals (although specific respiration rate, which is a stress indicator, was higher), but by the second year all populations had recovered except the earthworms, which are very sensitive to copper contamination. There is conflicting evidence suggesting that earthworm activity may reduce the net N mineralisation rate because of the immobilisation of N by microorganisms that increase dramatically in the earthworm gut. | |
| 34 | Fisher, A., Bailey, R.J. & Williams, D.J. | Growing potatoes using a bed-planting technique | 1995 | Potato Growing | Book | Cook, H.F. & Lee, H.C.; Soil Management in Sustainable Agriculture; 561-568 | English | Hardcopy:Full | Field expt. to test the growing of potatoes on flat beds | .. there is a yield advantage to be gained from growing potatoes in beds in certain situations. .. beds can be advantageous on light soils. ..improved water retention or efficiency of use is at least partly responsible. |
| 818 | Flavel, T.C. & Murphy, D.V. | Carbon and nitrogen mineralisation rates after application of organic amendments to soil | 2006 | Compost & Biocontrol; Soil Organic Carbon; Soil N Dynamics | Journal | J. Environ. Qual.; 35; 183-193 | English | Hardcopy:Full; PDF:Full | Lab. expt. to study the rates of C & N mineralisation in soil amended with various composts | @; There was a highly significant relationship between CO2-C evolution and gross N mineralisation.; The amount of gross N mineralised was .. significantly related to the total C and N, cellulose, lignin, ash and NO3--N contents of the amendments.; .. appl |
| 835 | Flessa, H., Ludwig, B., Heil, B. & Merbach, W. | The origin of soil organic carbon, dissolved organic carbon and respiration in a long-term maize experiment at Halle, Germany, determined by 13C natural abundance | 2000 | Soil Organic Carbon | Journal | J. Plant Nutr. Soil Sci.; 163 (2); 157-163 | English | Hardcopy:Partial | Field expt. to study the accumulation & mineralication of C in a maize field | After 37 years of continuous maize cropping, 15% of the total SOC in the topsoil originated from maize C. The fraction of maize-derived C below the ploughed horizon was only 3%-5%. The total amount of maize C stored in the profile was 9080 kg ha-1, which was .. about 31% of the estimated total C input via maize `residues (roots & stubble). The total CO2-C emission for 16 weeks was 18 g m-2. (58% of the soil respiration originated from maize C. The specific CO2 formation from maize-derived SOC was 8 times higher than that from the older SOC formed by C3 plants. |
| 1215 | Flessa, H., Potthoff, M. & Loftfield, N. | Greenhouse estimates of CO2 and N2O emissions following surface application of grass mulch: importance of indigenous microflora of mulch | 2002 | Greenhouse Gases; Mulch; Soil Microorganisms | Journal | Soil Biol. Biochem.; 34 (6); 875-879 | English | Hardcopy:Full; PDF:Full | 7-week lab.expt. to study the decomposition of a grass mulch on soil. Unless water stress or nutrient deficiency strongly reduces the activity of phyllosphere microflora, they predominate in the decomposition of surface-applied easily biodegradable N-rich mulches and autochthonous soil microbes have no effect. Substantial NH3 loss from N-rich mulches has been reported but evidence for increase N2O emis`sions is conflicting. In this expt only 0.3% of the applied N was lost as N2O. | |
| 219 | Flessa, H., Ruser, R., Dörsch, P., Kamp, T., Jimenez, M.A., Munch, J.C. & Beese, F. | Integrated evaluation of greenhouse gas emissions (CO2, CH4, N2O) from two farming systems in southern Germany | 2002 | Greenhouse Gases; Organic Farming | Journal | Agric. Ecosyst. Environ.; 91; 175-189 | English | Hardcopy:Partial; PDF:Full | Calculating the total greenhouse gas emissions from two farms - one conventional @and one organic. The aggregate emissions from the farms were 4.2 and 3.0 Mg CO2 equiv. per ha. respectively. Because of different crop rotations a strict comparison between the two farms was not possible, but, taking into account the lower yields from the organic farm, the emissions per unit yield were probably about equal. | (; N2O emissions from agriculture are estimated to account for more than 75% of the total global anthropogenic emission, the major part being produced in soils as an intermediate during nitrific'n & denitrific'n.; Agriculture and related activities account for about two-thirds of all anthropogenic CH4 emissions.; .. in systems with more intensive cattle production (2-3 animal units per hectare) .. CH4 emission from enteric fermentation & waste mgmt is the major contribution to the total emission of greenhouse gases.; .. livestock husbandry is a key factor determining GHG emission related to food production. This is due to the direct emissions from animals and animal wastes and, more importantly, to the low N efficiency of meat production, since about 80-95% of the N intake with feed is excreted as dung and urine. Therefore, the reduction of crop production for animal husbandry in favour of human nutrition represents one of the most efficient measures for mitigating greenhouse gas emissions from agriculture. |
| 638 | Flessa, H., Wild, U., Klemisch, M. & Pfadenhauer, J. | Nitrous oxide and methane fluxes from organic soils under agriculture | 1998 | Greenhouse Gases | Journal | Eur. J. Soil Sci.; 49; 327-335 | English | Hardcopy:Partial | Expt. to study the gas fluxes from cultivated drained peatland | .. peatlands are converted from sinks to sources of C and N by a lowering of xthe water table. .. Emissions of CH4 are much reduced after drainage. .. The @release of N2O generally increases after drainage. N2O is produced as an intermediate in denitrification and it is a by-product of nitrification.; .. large losses of N2O can occur from acid fen soils. The major part of the total annual emission occurred in the winter. .. Maximum emission rates occurred when temperatures fell below freezing point.; Due to intensive drainage all sites (were a net sink for atmospheric CH4. CH4 consumption was significantly affected by the kind of land use, with 4-5 times larger uptake on the intensively rooted meadows than on the arable sites. |
| 1002 | Fließbach, A., Dubois, D., Esperschütz, J., Gunst, L., Mäder, P., Oberholzer, H.R., Schloter, M., Gattinger, A. | Soil microbial community structure & OM transformation processes in org. & conv. farming systems | 2005 | Biodynamic Farming; Soil Organic Carbon; Soil Microorganisms | Website | Paper presented at Int. Sci. Conf. on Organic Agriculture, Adelaide | English | Hardcopy:Partial; Wordperfect:Full | Field expt. to study the SOM accumulation and microbial biomass in soils under differing agricultural management | Roughly 20% of the initial SOM was lost when no manure was applied for 21 years as in the CONMIN and the NOFERT system, whereas SOM increased slightly by 4% in the BIODYN system, which used composted farmyard manure .. The BIOORG and the CONFYM systems lost about 7%. Soil microbial biomass .. revealed higher values in organically fertilised plots. Bacterial and eukaryotic biomasses followed the order: CONMIN < CONFYM = BIOORG = BIODYN. |
| 134 | Fließbach, A., Eyhorn, F., Mäder, P., Rentsch, D.I. & Hany, R. | DOK long-term farming systems trial: microbial biomass, activity and diversity affect the decomposition of plant residues | 2001 | Biodynamic Farming; Organic Farming; Soil Microorganisms | Book | Rees, R.M., Ball, B.C., Campbell, C.D. & Watson, C.A. (eds.); Sustainable Management of Soil Organic Matter; | English | Hardcopy:Partial; Wordperfect:Full | Long-term field expt. to study the composition and degradation of OM in different farming systems | Crop yields were lower in the org. as compared with the conv'l farming systems: by 20% for winter wheat & up to 40% for potatoes. SOM & pH were markedly higher in the BIODYN system compared with the conventional and the unmanured systems; Even though total SOM differs between org. & conv'l agricultural systems, no substantial changes in the chemical compos'n ... were detectable. .. Labile SOM pools (SMB, light-fraction POM) indicated distinct changes in SOM dynamics. |
| 1216 | Fließbach, A., Mäder, P. | Microbial biomass and size-density fractions differ between soils of organic and conventional agricultural systems | 2000 | Biodynamic Farming; Organic Farming; Soil Microorganisms | Journal | Soil Biol. Biochem.; 32; 757-768 | English | Hardcopy:Full; PDF:Full | Expt. to compare the microbial activity and aggregation in soils under conventional and organic management | .. the amount of macro-OM (>150 m) is controlled by soil management, while the amount of C associated with clay and silt particles is controlled by soil texture. .. light fraction OM is sensitive to changes in C-input and can be used as an early indicator of management changes.; Among all the fractions, C/N ratios were smallest in the biodynamic soils.; Microbial biomass C & N as well as their ratios to the total and light fraction C & N pools in soils of the org. systems were higher than in conventional systems.; The metabolic efficiency of a microbial community is supposed to be reflected by their specific respiration rate. For the current study, qCO2 was lower in organic compared to conventional soils and since the substrate use diversity in organic soils has been found to be higher than in conventional ones, the hypothesis that a more diverse community has a higher metabolic efficiency is supported by our data. |
| 1217 | Fließbach, A., Mäder, P. & Niggli, U. | Mineralisation and microbial assimilation of 14C-labelled straw in soils of organic and conventional agricultural systems | 2000 | Biodynamic Farming; Organic Farming; Soil Microorganisms | Journal | Soil Biol. Biochem.; 32; 1131-1139 | English | Hardcopy:Partial; PDF:Full | Expt. to study the decomposition of straw in soil from org. & conv. systems. 4 treatments were used: untreated, chemical fertilisers only, FYM plus chemical fertilisers & biodynamic. The 2 latter treatments received FYM at the same rate based on 1.4 LU ha-1. The substrate-use efficiency (14Cmic/[14Cmic+14CO2-C]) was 0.30, 0.27, 0.30 and 0.34 for the four treatments respectively. Their Cmic/Corg ratios were 1.7%, 1.3%, 1.7% and 2.1% by weight respectively. | `The microbial respiration to microbial biomass ratio (qCO2 ) .. indicates the (energy needed for maintenance of microbial biomass. .. A high qCO2 .. indicates that nutrients are recycled quickly.; Microbial biomass C of the conventional soil was only 64% that of the biodynamic soils. .. crop yields in the BIODYN system were about 18% lower than in CONFYM. |
| 56 | Fluck, R.C. | Energy of human labour | 1992 | Energy in Agriculture | Book | Fluck, R.C. (ed.); Energy in Farm Production, vol. 6 of: Stout, B.A. (ed.), Energy in World Agriculture; 31-37 | English | Hardcopy:Full | The energy cost of human labour is calculated in two different ways - one, in the case of agriculture using no fossil fuels, is based on the energy of metabolised food, and the other, in the case of agriculture where fossil fuels are used, is based on the energy embodied in labour. | For primitive agricultural systems which [that?] consume no fossil fuel inputs it appears that a method based upon the energy of metabolised food is justifiable. .. the energy produced as a result of our work must suffice for all our .. activities. .. the total energy content of all food .. should be used under these circumstances. Where use of fossil fuels is prevalent, that energy subsidises all activities, including agricultural labour. Therefore the energy of human labour is the energy sequestered in labour. It appears that the netenergy analysis method is preferable since it includes only the energy sequestered in labour and excludes the remainder of energy which is instead sequestered in other goods and services of final consumption. |
| 178 | Fluck, R.C. | Energy productivity: a measure of energy utilisation in agricultural systems | 1979 | Energy in Agriculture | Journal | Agric. Sys.; 4; 29-37 | English | Hardcopy:Full | Energy productivity is defined and is advocated as a better measurement of agricultural efficiency than the energy ratio. The energy ratio (the ratio of energy output to energy input) is criticised for being inappropriate in the production of food, which is not only for energy, but even more so in the production of fibre and 'ornamentals'. Energy productivity (the ratio of the weight of agricultural product to the energy required to produce it) is more appropriate, although it is limited by being specific to each product. | .. foods are consumed for other reasons than their energy content only. .. In developed countries food is a form of entertainment, business function, a social amenity, a psychological escape or a form of peer acceptance. Only rarely is it used primarily as a source of nourishment ..; [it is wrong to infer] that in industrialised agriculture a ratio of less than unity is unacceptable .. farming for energy must be energetically sound, but there is no reason why farming for other products should cost less energy than is produced.; Comparisons have been made of the energy ratio of different agricultural products and of different cultures or agricultural systems. Such comparisons are meaningless and misleading.; Energy productivity is specific to each agricultural product, location and time. .. energy productivity can be used only to compare alternative production systems .. which result in the same product, at the same place, at the same time. |
| 1651 | Fluck, R.C. & Baird, C.D. | Agricultural Energetics | 1980 | Energy in Agriculture; Labour and Animal Power | Book | Fluck, R.C., & Baird, C.D.; Agricultural Energetics; | English | Hardcopy:Full | The energy inputs and the application of energy analysis to agriculture are examined (general review). The energy expended by labour is evaluated from different points of view (pp. 98-105). The energetics of greenhouse growing and transport from warmer climates, of mechanisation and manual labour and of crops and livestock are all compared. | Lifestyle support energy .. is the total energy sequestered in the services consumed by the farm worker and .. family.; Net energy analysis .. involves a dis-aggregation of the GNP into its components and estimation of the energy content and portion of each consumed as feed back to provide labour.; .. the energy sequestered in all United States agricultural labour in 1974 is estimated to be 594 MJ.d-1 [which] is approximately 45 times the value heretofore most widely used, 13 MJ.d-1, based on food caloric energy consumption.; .. 10 to 25 times as much energy is required for heating greenhouses as for trucking .. a given quantity of tomatoes [from Florida or Mexico to New York].; Greenhouse tomatoes required 50.3 MJ.kg-1 whereas field-grown required 0.9 MJ.kg-1.; Man is not competitive on an energetics basis with machinery .. |
| 443 | Fog, K. | The effect of added nitrogen on the rate of decomposition of organic matter | 1988 | Lignin and CBW; Soil Organic Carbon | Journal | Biol. Rev. (Camb.); 63; 433-462 | English | Hardcopy:Partial | Review of research on the effect of added N on the decompos'n rate of OM. In a survey of various substrates the effect of N addition was to retard decompos'n in all cases except deciduous leaf litter and FYM (slight). With cellulose the effect is always to accelerate decomposition and with lignin to slow it down. | .. the negative effect of addition of N can last for several years.; .. some data indicate that not all N immobilised is actually necessary for the decomposers.; .. for decomposition of straw at two different levels of added N .. at both levels nearly all N supplied was immobilised .. at the high N level the rate of decomposition was slightly lower than at the low level i.e. the extra N was not necessary for microbial activity - it was a luxury uptake. |
| 1110 | Foley, J.A., Fries, R. de, Asner, G.P., Barford, C., Bonan, G., Carpenter, S.R., Chapin, F.S., Coe, M.T., Daily, G.C., Gibbs, H.K., Helkowski, J.H., Holloway, T., Howard, E.A., Kucharik, C.J., Monfreda, C., Patz, J.A., Prentice, I.C., Ramankutty, N. & Snyder, P.K. | Global consequences of land use | 2005 | Sustainability | Journal | Science; 309; 570-574 | English | Hardcopy:Full; PDF:Full | Review of ecological consequence of human land use and how it can be improved | We face the challenge of managing trade-offs between immediate human needs and maintaining the capacity of the biosphere to provide goods and services in the long term.; Since 1850 roughly 35% of anthropogenic CO2 emissions resulted directly from land use.; .. anthropogenic nutrient inputs to the biosphere from fertilisers and atmospheric pollutants now exceed natural sources .. Human activities now appropriate nearly one third to one half of global ecosystem (production.; Global water withdrawals now total 3900 km3 yr-1 or 10% of the total global renewable resource and the consumptive use of water (not returned to the watershed) is estimated to be 1800 to 2300 km3 yr-1. Agriculture alone accounts for 85% of global consumptive use. |
| 1537 | Follett, R.F. | Soil management concepts and carbon sequestration in cropland soils | 2001 | Soil Organic Carbon; Tillage | Journal | Soil Tillage Res.; 61 (1-2); 77-92 | English | Hardcopy:Partial | Review of the use of management techniques to increase SOM accumulation in the U.S.A. | |
| 859 | Follett, R.F. & Delgado, J.A. | Nitrogen fate and transport in agricultural systems | 2002 | Mineralisation; Soil N Dynamics | Journal | J. Soil Water Conserv.; 57 (6); 402-408 | English | Hardcopy:Full | Review of current knowledge about the N cycle. The active pool, slow pool and passive pool of SOM are defined. Figures are given on the recycling of forage N by livestock and the fate of fertiliser N. | Soil bacteria are integral to the immobilisation and mineralisation of SON .. Heterotrophic organisms use SOC as a source of energy, driving the aminisation and ammonification processes. Autotrophic nitrosomonas transform the ammonium to nitrite and nitrobacter transform the nitrite to nitrate. Bacteria obtain energy through the oxidation of these compounds.; Global N fixation from the use of legumes in agriculture [is estimated] at 40,000 Gg N/year.; Nitrate is a negatively charged ion repelled by the negatively charged clay mineral surfaces in soil.; .. over 50 years more than 80% of the N applied to a field will eventually return to the atmosphere through denitrification .. greater than H 95% .. as N2 gas but some unknown amount as N2O. |
| 1419 | Follett, R.F., Paul, E.A., Leavitt, S.W., Halvorson, A.D., Lyon, D. & Peterson, G.A. | Carbon isotope ratios of great plains soils and in wheat-fallow systems | 1997 | Soil Organic Carbon | Journal | Soil Sci. Soc. Am. J.; 61 (4); 1068-1077 | English | Hardcopy:Partial | Natural C isotope abundance methods were used to compare the SOM in samples taken from various sites, including two long-term field expt.s, which had been cultivated since 1909 and 1970 respectively. On the former site, by 1993, in the 0 to 15 cm depth, the total SOC and the native-vegetation-derived SOC had decreased to 61% and 46% of their original 1909 values respectively and about 24% of the SOC was from winter wheat. | .. continuous cultivation initially depletes near-surface soil-C stocks and, with increasing time of cultivation deeper soil-C stocks are depleted.; .. the 13C in the SOC in native grassland surface and sub-surface soils from the Great Plains in North America becomes less negative from north to south as the result of a broad regional shift from predominantly C3 to C4 vegetation.; Regional H patterns of 13C in the Great Plains show consistent trends of more negative 13C in younger surface soils than in older sub-surface soils (based on 14C dating). |
| 584 | Fontaine, S. & Barot, S. | Size and functional diversity of microbe populations control plant persistence and long-term soil carbon accumulation | 2005 | Priming Effect; Soil Organic Carbon; Soil Microorganisms | Journal | Ecol. Lett.; 8; 1075-1087 | English | Hardcopy:Partial; PDF:Full | Modelling the decomposition of SOM with the inclusion of the priming effect | We present an alternative theory of SOM dynamics, in which SOM decay rate is controlled by the size & the diversity of microbe popul'ns & by the supply of energy-rich litter cpds.; .. the priming effect has important consequences on SOM dynamics. The supply of fresh OM can increase the mineralis'n of SOM by 12%400% .. Increased rates of SOM mineralis'n persist in soil for several months after the complete decomposition of fresh OM, which leads to important C losses. Such priming may even induce a negative C balance, i.e. the supply of C decreases the total soil C content. |
| 583 | Fontaine, S., Bardoux, G., Abbadie, L. & Mariotti, A. | Carbon input to soil may decrease soil carbon content | 2004 | Priming Effect; Soil Organic Carbon | Journal | Ecol. Lett.; 7 (4); 314-320 | English | Hardcopy:Full; PDF:Full | Expt. to study the relationship between plant residue input and SOM content | It is commonly predicted that the intensity of primary production and soil C content are positively linked. Paradoxically many long-term field observations show that, although plant litter is incorporated to soil in large quantities, soil C content does not necessarily increase. These results suggest that a negative relationship between C input and soil C conservation exists.; .. the supply of fresh C may accelerate the decomposition of soil C and induce a negative C balance. .. soil C losses increase when soil microbes are nutrient limited.; .. energy available to soil microbes and microbial competition are important determinants of soil C decomposition. |
| 1420 | Fontaine, S., Bardoux, G., Benest, D., Verdier, B., Mariotti, A. & Abbadie, L. | Mechanisms of the priming effect in a savanna soil amended with cellulose | 2004 | Priming Effect; Soil Organic Carbon | Journal | Soil Sci. Soc. Am. J.; 68; 125-131 | English | Hardcopy:Full; PDF:Full | Lab. expt. to study the effect of priming a soil with cellulose | Two mechanisms have been hypothesised to explain the priming effect .. extracellular enzymes that are produced to decompose fresh C by fresh-C-specialised microbes may be partly efficient in degrading soil C .. [or] depending on the competition with fresh-C-specialised microbes, part of the fresh C may be absorbed by soil-C-decomposing microbes .. [which] increases the populations of soil-C-decomposing microbes and hence the decomposition rate of soil C.; The rate of soil C decomposition increased by 55% with cellulose addition .. |
| 1218 | Fontaine, S., Mariotti, A. & Abbadie, L. | The priming effect of organic matter: a question of microbial competition? | 2003 | Priming Effect; Soil Microorganisms | Journal | Soil Biol. Biochem.; 35 (6); 837-843 | English | Hardcopy:Full; PDF:Full | Review of work done to date on the priming effect, the increase in SOM decomposition rate after fresh OM input to soil, which had been supposed to result from a general increase in microbial activity due to the higher availability of energy released by the decomposition of fresh OM | Work to date .. suggests that supply of available energy induces no effect on SOM mineralisation.; After fresh OM input to soils, many specialised microorganisms grow quickly and only decompose the fresh OM. .. the priming effect results from the competition for energy and nutrient acquisition between the microorganisms specialised in the decomposition of fresh OM [r-strategists] and those feeding on polymerised SOM [K-strategists]. |
| 1219 | Fonte, S., Kong, A.Y., Kessel, C. van, Hendrix, P.F. & Six, J. | Influence of earthworm activity on aggregate-associated carbon and nitrogen dynamics differs with agroecosystem management | 2007 | Organic Farming; Soil Organic Carbon; Soil N Dynamics | Journal | Soil Biol. Biochem.; 39; 1014-1022 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the effect of eaarthworms on C & N cycling in diffrent farming systems | .. earthworms have important effects on C & N cycling processes ... their influence depends greatly on differences in management. We found earthworms to increase the incorporation of cover-crop-derived C into macroaggregates and more importantly into microaggregates formed within macroaggregates ... [which] indicates the potential for earthworms to facilitate SOM stabilisation and accumulation in agricultural systems. The influence of earthworms on N cycling, however, appears to be largely determined by cropping system and the form of fertiliser applied (mineral vs. organic).; .. earthworms have potentially negative consequences on fertiliser-N retention. |
| 540 | Forrer, H.R., Musa, T., Krebs, H. & Dorn, B. | Control of Phytophthora infestans in organic potato production | 2006? | Potato Growing | Book | Forrer, H.R., Musa, T., Krebs, H., & Dorn, B. ; E.U. project no.: QLK5-CT-2000-01065; | English | Hardcopy:Full; PDF:Full | Field expt. to test 26 different CFPs (copper-free preparations) for the biocontrol of LB (late blight) on potatoes | .. no commercial or experimental CFP with a reliable activity for LB control could be found.; Though all CFP treatments reduced LB significantly, none of them reached the 25% efficacy level.; [i.e. 25% reduction in foliar blight]; .. a main cause of failure could be a low stability towards rain or dew. |
| 290 | Fortin, M.C. & Pierce, F.J. | Developmental and growth effects of crop residues on maize | 1990 | Mulch; Soil Organic Carbon | Journal | Agron. J.; 82; 710-715 | English | Hardcopy:Full | Field expt. to test the effect on maize growth of a straw mulch compared with bare soil. | .. no consistent difference was found in aboveground phytomass when comparisons were done at similar vegetative stages.; .. when aboveground phytomass data were examined at various dates [instead of at vegetative stages] the residue treatment had consistently lower values than the bare treatment. |
| 291 | Fortin, M.C. & Pierce, F.J. | Timing and nature of mulch retardation of maize vegetative development | 1991 | Allelopathy; Mulch; Soil Organic Carbon | Journal | Agron. J.; 83; 258-263 | English | Hardcopy:Full | Field expt. to compare the vegetative development of maize under two treatments - bare soil and oat straw mulch | .. complete residue cover applied at LTE2 [second leaf tip emergence] on a notill loam soil resulted in delays of 5 to 7.5 days in vegetative .. development of maize. .. in addition to the soil temperature effect, other factors contributed to the delay in maize development .. allelopathy may be the source of unexplained delay. |
| 135 | Fortune, S., Conway, J.S., Philipps, L., Robinson, J.S., Stockdale, E.A. & Watson, C.A. | N, P and K budgets for some U.K. organic farming systems: implications for sustainability | 2001 | Organic Farming | Book | Rees, R.M., Ball, B.C., Campbell, C.D. & Watson, C.A. (eds.); Sustainable Management of Soil Organic Matter; | English | Hardcopy:Partial; Wordperfect:Full | Review of the use of nutrient budgets in organic farming | '.. organic systems are inherently liable to nitrogen leaching'. The often reduced inputs of P & K to org. farming systems are believed to lead to negative P & K balances. Johnston (1991) suggested that organic systems are not inherently more sustainable than conventional farming, especially with regard to the long-term availability of P and K. |
| 1720 | Fox, O., Vetter, S., Ekschmitt, K. & Wolters, V. | Soil fauna modifies the recalcitrance-persistence relationship of soil carbon pools | 2006 | Uncategorised | Journal | Soil Biol. Biochem.; 38; 1353-1363 | English | PDF:Full | ||
| 159 | Fragstein, P. von | Organic arable farming - a contradiction? | 1996 | Stockless Farming | Book | van Ittersum, M. K., Venner, G. E. G. T., van de Geijn, S. C. & Jetten, T. H. (eds.); Fourth Congress of the ESA - Book of Abstracts, Vol. 2. European Society for Agronomy; 438-439 | English | Hardcopy:Full | A review of the pros and cons of stockless organic farming and of the literature published on it. [The very poor English makes most of this paper difficult to understand.] | |
| 93 | Fragstein, P. von & Schmidt, H. | External N sources in an organic stockless crop rotation: useful or useless additives? | 1999 | Compost & Biocontrol; Stockless Farming | Book | Olesen, J.E., Eltun, R., Gooding, M.J., Jensen, E.S & Köpke, U. (eds); Designing & testing crop rotations for organic farming. Proceedings from an international workshop; | English | Hardcopy:Partial; Wordperfect:Full | 3-year field expt. to test stockless organic rotations with various amendments | From the perspective of sustainability the .. rotation has a need for further N-inputs apart from green manure crops. In stockless systems source-separated composts are suitable for the compensation of nutrient balances & the long-term improvement of SOM. Vinasse suits for the input of N & K and makes possible a direct manipulation of plant growth due to its high availability of N.; The short-term effect of source separated composts can be graded as very small. Quick responses of plant growth to compost application cannot be expected .. |
| 57 | Francis, C.A., Flora, C.B. & King | What is sustainable agriculture? | 1990 | Sustainability | Book | Francis, C.A., Flora C.B. & King (ed.); Sustainable Agriculture in Temperate Zones; 3-11 | English | Hardcopy:Full | Sustainable agriculture is defined. Common misconceptions about it are dispelled. | A sustainable agriculture is one that, over the long term, enhances environmental quality and the resource base on which agriculture depends; provides for basic human food and fibre needs; is economically viable; and enhances the quality of life for farmers and society as a whole.; .. most current definitions of sustainable agriculture allow for some use of synthetic inputs. |
| 344 | Franke-Snyder, M., Douds, D.D., Galvez, L., Phillips, J.G., Wagoner, P., Drinkwater, L.E. & Morton, J.B. | Diversity of communities of arbuscular mycorrhizal (AM) fungi present in conventional versus low-input agricultural sites in eastern Pennsylvania | 2001 | Green Manure; Organic Farming; Stockless Farming | Journal | Appl. Soil Ecol.; 16; 35-48 | English | Hardcopy:Partial | Comparison of AM fungal communities in soils from a conventional rotation and two organic rotations - one using FYM and the other - green manure. Little difference was found in the fungal diversity between the three treatments. | .. microbial communities [including AM fungi] .. are involved in processes such as acquisition and recycling of nutrients .., antagonism of detrimental organisms and participation in the formation and maintenance of soil structure. |
| 345 | Franzluebbers, A.J. | Microbial activity in response to water-filled pore space of variably eroded southern Piedmont soils | 1999 | Soil Microorganisms | Journal | Appl. Soil Ecol.; 11; 91-101 | English | Hardcopy:Partial; PDF:Full | Expt. to test water-filled pore space as an alternative to matric potential as a measure of of the effect of soil water content on soil microorganisms | Soil microbial activity is known to be strongly influenced by soil water content. Soil CO2 evolution increases with water additions above -5000 kPa up to a maximum near -15 kPa and subsequently declines near saturation due to O2 limitations. Net N mineralisation has been shown to follow a similar response to soil matric potential although a stronger decrease in net N mineralisation occurs near saturation compared with C mineralisation. Nitrate serves as an alternative electron acceptor when O2 becomes limiting, resulting in the conversion of NO3- to N2 or N2O via denitrification.; ..the matric potential to achieve maximum microbial activity ranged from -10 to -400 kPa for individual soils.; Matric potential is logarithmically related to gravimetric soil water content with the relationship depending mainly upon soil texture and OM content. The water retention curve of a soil can also be altered with changes in the BD. |
| 1538 | Franzluebbers, A.J. | Soil organic matter stratification ratio as an indicator of soil quality | 2002 | Soil Organic Carbon; Tillage | Journal | Soil Tillage Res.; 66 (2); 95-106 | English | Hardcopy:Partial | The results of an expt. to test the hypothesis that the degree of stratification of SOC & -N pools with soil depth, expressed as a ratio, could be an indicator of soil quality. Because of the stratification of SOC in zero tillage soil the absolute quantity of SOC in a soil is not a good indicator of soil quality. | .. [on the three sites tested] stratification ratios of SOC were 1.1, 1.2 and 1.9 under conventional tillage (CT) and 3.4, 2.0 and 2.1 under no-tillage (NT) .. respectively.; Stratification of biologically active soil C & N pools (i.e. soil microbial biomass and potential activity) were equally or more sensitive to tillage, cropping intensity and soil textural variables than stratification of total C & N. High stratification ratios of soil C & N pools could be good indicators of dynamic soil quality, independent of soil type and climatic regime .. |
| 1539 | Franzluebbers, A.J. & Arshad, M.A. | Soil organic matter pools with conventional and zero tillage in a cold semi-arid climate | 1996 | Soil Organic Carbon; Tillage | Journal | Soil Tillage Res.; 39; 1-11 | English | Hardcopy:Partial | In a field expt. the SOC depth distribution, soil microbial biomass, soil basal respiration and net N mineralisation were compared on plots subject to chiselploughing and zero tillage. On average soils were 4% denser and 24% wetter under zero tillage. The average basal soil respiration rates were 4.0 and 3.1 CO2C/m2/day and the net N mineralisation rates were 3.4 and 4.1 g/m2/24 days under chisel and zero tillage respectively. In this cold semi-arid climate the SOC and active C pools were not enriched by reduced tillage, as they are in more temperate and humid climates. | |
| 1540 | Franzluebbers, A.J. & Hons, F.M. | Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no-tillage | 1996 | Soil Organic Carbon; Tillage | Journal | Soil Tillage Res.; 39; 229-239 | English | Hardcopy:Partial | Expt. to study the distribution of nutrients in the soil after different tillage methods | greater water-filled pore space under NT compared with CT may have contributed to the higher levels of extractable Fe, Mn and Cu under NT by providing a more reduced soil condition.; these nutrients under NT tended to be present in higher levels that under CT, especially near the soil surface .. due to surface placement of crop residues. .. [This] was beneficial .. by allowing accumulation near the soil surface where plant roots tend to be most active. |
| 1541 | Franzluebbers, A.J., Hons, F.M. & Zuberer, D.A. | Tillage-induced seasonal changes in soil physical properties affecting soil CO2 evolution under intensive cropping | 1995 | Soil Organic Carbon; Tillage | Journal | Soil Tillage Res.; 34; 41-60 | English | Hardcopy:Partial | Field expt. to establish how tillage and soil CO2 evolution are related to soil temperature, BD and water-filled pore space and to the dynamics and distribution @of gravimetric soil water content. The mean rate of soil CO2 evolution was 1.98 g CO2-C/m2/day under chisel ploughing and 2.11 under zero tillage. | Tillage caused disruption and mixing of the soil, which allowed the soil to dry more rapidly, become more loosely aggregated, lose more heat during the night `and evolve less CO2 due to the reduced concentration of SOC. |
| 1619 | Franzluebbers, A.J., Hons, F.M. & Zuberer, D.A. | Seasonal dynamics of active soil C & N pools under intensive cropping in conventional and no tillage | 1996 | Soil Organic Carbon; Soil N Dynamics; Tillage | Journal | Z. Pflanz. Bodenkunde; 159; 343-349 | English | Hardcopy:Partial | Field expt. to determine the effect of tillage on the seasonal dynamics of potential C & N mineralisation, soil inorganic N and soil microbial biomass C and its specific respiratory activity. | .. the size and activity of the active soil C & N pools of SOM are seasonally dependent.; .. increased C input, rather than reduced microbial activity, led to conservation of SOM in this soil. |
| 1421 | Franzluebbers, A.J., Wright, S.F. & Stuedemann, J.A. | Soil aggregation and glomalin under pastures in the southern Piedmont USA | 2000 | Soil Microorganisms; Soil (General) | Journal | Soil Sci. Soc. Am. J.; 64; 1018-1026 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the relationship between glomalin and aggregation | Total glomalin .. was highly related to whole soil organic C content, but neither of these properties was particularly well related with water-stable macroaggregation, mean-weight diameter or their stabilities.; Although soil biological activity and deposition of glomalin by AM fungi, of carbohydrates by various microorganisms, of muramic acid by bacteria and of glucosamine by fungi may be essential in binding soil aggregates, other physical and chemical factors appear to be equally important in the development of strong aggregate distribution and stability properties of soils .. These factors may be: the extent of physical weathering of soils, high Al and Fe contents and intense drying-wetting cycles .. |
| 346 | Fraser, P.M. & Piercy, J.E. | The effects of cereal straw management practices on lumbricid earthworm populations | 1998 | Green Manure; Soil (General) | Journal | Appl. Soil Ecol.; 9 (1-3); 369-373 | English | Hardcopy:Partial; PDF:Full | 4-year field expt. to study the effect of straw residue management and green manures on earthworm populations on land that had been 4 yrs under grass | Overall ... there was a gradual decline in both the size of the total earthworm populations and earthworm biomass over the first 4 yr of the experiment in the continuous cereal treatments. Burning and removing straw had similar effects on earthworm numbers. However, by year 4 there were considerably more earthworms in the incorporation treatment plots, indicating that there may be some longterm effects of straw management on earthworm populations. In the treatment undersown with clover seed, the earthworm numbers, biomass and species diversity increased dramatically in the fourth year. This may be attributed to the clover plants providing a suitably moist and cool microclimate conducive for earthworm survival and the high protein content of the clover plants providing a rich food source for the earthworms and the microorganisms.; [or to the less cultivation?] |
| 950 | Freney, J.R. | Emission of nitrous oxide from soils used for agriculture | 1997 | Greenhouse Gases; Green Manure | Journal | Nutr. Cycl. Agroecosyst.; 49; 1-6 | English | Hardcopy:Full; PDF:Full | Review of N2O emissions from agricultural soils | N2O production is controlled by temperature, pH, water holding capacity of the soil, .. fertiliser rate, tillage practice, soil type, O2 concentration, availability of C, vegetation, land use practices and use of chemicals. .. emissions from agricultural soils are increased by the addition of fertiliser N and by the growth of legumes to fix atmospheric nitrogen.; .. predictions of N2O emissions associated with N applied are not reliable. Soil management and `cropping systems and variable rainfall have a greater effect on N2O emission than (the type of fertiliser nitrogen.; .. legumes may contribute to N2O emission in a number of ways. Atmospheric N fixed by the legumes can be nitrifed and denitrifed in the same way as fertiliser N, thus providing a source of N2O. .. symbiotically living Rhizobia in root nodules are able to denitrify and produce H N2O. .. legumes can increase N2O emissions from pastures by a factor of 2 to 3. |
| 1220 | Frey, B. & Schüepp, H. | A role of vesicular-arbuscular (VA) mycorrhizal fungi in facilitating interplant nitrogen transfer | 1993 | Green Manure; Soil Microorganisms; Soil N Dynamics | Journal | Soil Biol. Biochem.; 25 (6); 651-658 | English | Hardcopy:Partial | The transfer of N from a legume (berseem) to associated non-leguminous plants (maize and apple) was studied with and without innoculation of the legume roots with V.A.M. fungus. A significant quantity of N was transferred to the nonlegume in both cases, though the quantity was much smaller with the maize than with the apple. | |
| 1221 | Frey, S.D., Elliott. E.T. & Paustian, K. | Bacterial and fungal abundance and biomass in conventional and no-tillage agroecosystems along two climatic gradients | 1999 | Soil Microorganisms; Tillage | Journal | Soil Biol. Biochem.; 31 (4); 573-585 | English | Hardcopy:Full; PDF:Full | Expt. to determine the factors controlling absolute and relative microbial populations and biomass in soils taken from six long-term tillage expt.s. In the surface soil the F/B ratio was significantly higher under CT than under NT, although generally bacterial biomass was greater than fungal. | The proportion of the total biomass composed of fungi ranged from 10 to 60% and was significantly higher in NT compared to CT .. [It] was not strongly related to soil texture, pH, aggregation or organic C & N fractions, but was positively related to soil moisture.; Bacterial abundance and activity decline rapidly as soil water content falls below field capacity & bacterial respiration & .. transformations are negligible at potentials blow -1.5 MPa. Many fungi are active at considerably lower water potentials.; Expressed as a percentage of TOC, total microbial biomass (bacterial+fungal C) ranged from 0.3 to 0.8%. There were no differences between CT and NT soils for this variable.; .. previous studies have shown that fungi are the dominant decomposers of NT surface residues. |
| 1222 | Frey, S.D., Elliott. E.T., Paustian, K. & Peterson, G.A. | Fungal translocation as a mechanism for soil nitrogen inputs to surface residue decomposition in a no-tillage agroecosystem | 2000 | Mulch; Soil Microorganisms; Soil N Dynamics | Journal | Soil Biol. Biochem.; 32 (5); 689-698 | English | Hardcopy:Partial | Expt. to measure the rate of N flux from the mineral soil to surface-applied crop residues | @; We estimate a total annual fungal-mediated N flux of 2.4 g m-2, which is nearly equivalent to the N immobilization potential predicted, based on initial N and lignin content, for the wheat straw used in this study. We conclude that fungal N translocati |
| 704 | Frey, S.D., Knorr, M., Parrent, J.L. & Simpson, R.T. | Chronic nitrogen enrichment affects the structure and function of the soil microbial community in temperate hardwood and pine forests | 2004 | Soil Microorganisms; Soil N Dynamics | Journal | For. Ecol. Manag.; 196; 159-171 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the effect of chronic nitrogen enrichment on the soil nmicrobial community | Active fungal biomass was 27-61% & 42-69% lower in the fertilised compared to control plots in the hardwood & pine stands respectively. Active bacterial biomass was not greatly affected by N additions, resulting in significantly lower F/B biomass ratios in the N-treated plots. This .. was accompanied by a significant reduction in the activity of phenol oxidase, a lignin-degrading enzyme produced by white-rot fungi. In the pine stand ectomycorrhizal fungal community diversity was lower in the low N-treated plot .. |
| 1223 | Frey, S.D., Six, J. & Elliott, E.T. | Reciprocal transfer of carbon and nitrogen by decomposer fungi at the soil-litter interface | 2003 | Mulch; Soil Organic Carbon; Soil Microorganisms | Journal | Soil Biol. Biochem.; 35 (7); 1001-1004 | English | Hardcopy:Full; PDF:Full | Expt. to study the reciprocal translocation of C & N between litter and the soil by the action of decomposer fungi | .. C & N were reciprocally transferred by [saprophytic] fungi, with a significant quantity (121-151 g C g-1 whole soil) of litter-derived C being deposited into newly formed macroaggregates (>250 m sized aggregates). Fungal inhibition reduced fungal biomass and the bidirectional C & N flux by approximately 50%. The amount of litter-derived C found in macroaggregates was positively correlated with litter-associated fungal biomass. This fungalmediated litter-to-soil C transfer .. may represent an important mechanism by which litter C enters the soil and becomes stabilised as SOM within the macroaggregate structure. |
| 262 | Frissel, M.J. | Description and classification of agro-ecosystems | 1978 | Agricultural Ecology | Book | Frissel, M.J. (ed.); Cycling of Mineral Nutrients in Agricultural Ecosystems; 17-24 | English | Hardcopy:Partial | The various agricultural systems in the world are defined and compared, mainly in relation to their efficiency in the use of N. A table shows the N output (in kg/ha) of all the systems discussed. | For a part this system [extensive arable farming] depends on the decomposition of the organic soil fraction which was formed before agriculture was practised. .. The reclaimed Lake Kopais in Greece had lost its natural fertility within 15 years .. In Saskatchewan .., where the temperature is considerably lower, soils which have already been in production for about 100 years have lost only about one third of the N stored in the SOM. .. After the depletion period the soils are abandoned or use is also made of manure or fertilisers.; [i.e. transition to mixed or intensive farming] |
| 66 | Fuchs, J.G. | Practical use of quality compost for plant health and vitality improvement | 2002 | Compost & Biocontrol | Book | Insam, H., Riddech, N. & Klammer, S. (eds.); Microbiology of Composting; | English | Hardcopy:Partial; Wordperfect:Full | Lab. expt. to test the effect of composts of varying maturity on the ability of the compost to suppress plant diseases | The composition and the maturity of the compost influence the potential for suppression of plant disease. The management of the composting processes, and the oxygen supply in particular, seem to affect compost quality strongly.; Whereas some composts showed no reaction to Pythium ultimum on cress plants, other composts showed full protection against this disease. After a heat treatment (1 day at 90$C) the suppressive composts lose their potential for disease suppression. This indicates that disease suppression is linked with the microbiological activity of the composts |
| 179 | Fujisaka, S., Harrington, L. & Hobbs, P.R. | Rice-wheat in South Asia: systems and long-term priorities established through diagnostic research | 1994 | Miscellaneous | Journal | Agric. Sys.; 46 (2); 169-187 | English | Hardcopy:Partial | Rice-wheat growing in South Asia is reviewed from the standpoint of agronomic and sustainability problems. | System problems include poor wheat populations caused by the poor soil structure and plough pan formed for puddled rice, late wheat planting resulting from late rice harvesting and losses to grassy weeds encouraged by continuous rice-wheat cultivation. Sustainability issues include soil nutrient depletion and possible build-up of insects, weeds and diseases. |
| 379 | Fustec, E., Chauvet, E. & Gas, G. | Lignin degradation and humus formation in alluvial soils and sediments | 1989 | Lignin and CBW | Journal | Appl. Environ. Microbiol.; 55 (4); 922-926 | English | Hardcopy:Full | 7-week field expt. to study the fate of lignin from different tree species (poplar, willow and alder) in silty alluvial soil taken from beneath the trees xand in its size fractions. 10-15% of the lignin-C was evolved as CO2 and 65-75% was found in the coarse fractions (>50 m) of the soil. 5.3%, 3.1% and 24% of the lignin-C was found in complex humic polymers (humic and fulvic acids), mainly in the coarse fractions. | Although the soil beneath willows was waterlogged and flooded each year, its lignin mineralisation potentialities seemed to be higher than that of other alluvial soils, but .. the humification process was much slower. .. In soil beneath alders [which is waterlogged but not flooded] the mineralisation of lignin was not very different, but humic and fulvic acid formation appeared to be more rapid. |
| 318 | Gadgil, M. & Solbrig, O.T. | The concept of r- and K-selection: evidence from wild flowers and some theoretical considerations | 1972 | Miscellaneous | Journal | Am. Nat.; 106 (947); 14-31 | English | Hardcopy:Partial | Review of the evidence for r- and K-strategies among herbaceous plants | The most important characteristic of an r-strategist is that it devotes a greater proportion of available resources to reproduction than a related Kstrategist. This implies a higher birth rate;; ... populations living in environments imposing high density-dependent regulation (K-strategists) will be selectively favoured to allocate a greater proportion of resources to nonreproductive activities, at the cost of their capabilities to propagate under conditions of high density-independent mortality. |
| 609 | Gahoonia, T.S. & Nielsen, N.E. | Variation in root hairs of barley cultivars doubled soil phosphorus uptake | 1997 | Phosphorus Cycling; Roots & Rhizodeposition | Journal | Euphytica; 98; 177-182 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the part played by root hairs in P uptake. One cultivar with longer and denser root hairs could exploit nearly 3 times more soil and was able to intercept more labile P (NaHCO3-P) diffusing towards the roots, but not dissolve more P from stable P fractions. | In soil diffusion of P to the root surface is rate limiting ..; A large part of plant-available P in soil may be located in small-diameter pores. Root hairs can penetrate these pores and act as an extension of effective root-soil contact. Curled root hairs .. indicated that root hairs grew into soil pores. |
| 1033 | Gahoonia, T.S. & Nielsen, N.E. | The effects of root-induced pH on the depletion of inorganic and organic phosphorus in the rhizosphere | 1992 | Phosphorus Cycling | Journal | Plant Soil; 143; 185-191 | English | Hardcopy:Partial | Study of the increased uptake of soil P as a result of a root-induced pH reduction in the rhizosphere of rape plants. P-starved rape plants may exude substantial amounts of organic acids, but the pH decrease seems to be mainly due to a higher net inflow of cations than anions. The root-induced pH reduction causes a 20% increase in the total P depletion in the rhizosphere. The depletion of certain P fractions is even greater - KHCO3-Pi and residual P are increased by 34% and 43% respectively. 11-15% of total P withdrawn originated from organic P fractions and this was not affected by the pH change. | .. 40-46% of the P withdrawn near the root mat of rape originated from nonmobile fractions normally not included in .. plant-available soil P.; Shortterm mineralisation of organic P in the rhizosphere thus seems to be of importance in plant nutrition.; About 15-18% of total P depletion .. originated from the residual P, thus showing that rather non-mobile P may become mobile if roots strongly deplete the mobile P pool in the rhizosphere. |
| 1034 | Gahoonia, T.S. & Nielsen, N.E. | Direct evidence on participation phosphorus of root hairs in phosphorus (32P) uptake from soil | 1998 | Phosphorus Cycling | Journal | Plant Soil; 198; 147-152 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to measure the proportion of P taken up via root hairs, which have a functional lifetime of 2-3 days and are the site of infection in Rhizobiumlegume symbiosis. | The presence of 32P in the shoot in just 2 days showed that the plants absorbed P via root hairs and that it was translocated to the shoot.; .. the presence of radioisotope P in the shoots shows a substantial participation of root hairs in uptake of P from soil.; .. when 70 percent of the root hairs grew into the labelled soil, they contributed to 63 percent of the total P uptake.; The abundance of root hairs increases when P supply is lowered. |
| 639 | Gaillard, V., Chenu, C., Recous, S. & Richard, G. | Carbon, nitrogen and microbial gradients induced by plant residues decomposing in soil | 1999 | Soil Organic Carbon; Soil Microorganisms | Journal | Eur. J. Soil Sci.; 50; 567-578 | English | Hardcopy:Partial; PDF:Full | 100-day lab. expt. to study the microbial activity close to incorporated straw residues. Up to 4 mm from the surface of the straw (named the detritussphere) there was a steep downward gradient in microbial activity, presumably because of diffusion of soluble organic matter from the straw. | .. microorganisms and organic materials are heterogeneously distributed in the soil matrix and often separated from each other by physical barriers such as clay particles, which presumably limit the physical access of organic substrates to microorganisms. Disrupting the soil structure by grinding .. leads to rapid mineralisation of organic matter.; We..define four distinct spatial compartments. The first was the straw or particulate fraction, densely colonised by microorganisms .. The second was the adhering soil, also densely colonised and containing high C and N contents. A third .. was the soil situated to about 4 mm from the straw surface, in which dehydrogenase activity was stimulated and in which the C and N derived from the straw accumulated. The last compartment was the soil situated further than 4 mm from the straw; it was not affected by the decomposing straw except for a little accumulation of N derived from the straw.; The decomposition and mineralisation of the straw residues was brought about by microorganisms either on the surfaces of residues or in the soil within 4 mm from the straw residues. |
| 1422 | Gale, W.J. & Cambardella, C.A. | Carbon dynamics of surface-residue- and root-derived organic matter under simulated no-till | 2000 | Roots & Rhizodeposition; Soil Organic Carbon; Tillage | Journal | Soil Sci. Soc. Am. J.; 64 (1); 190-195 | English | Hardcopy:Partial | Expt. to subject a soil that had been under continuous maize and conventional tillage for 30 years to simulated zero tillage | .. C retention is increased in no-till because the surface residue is primarily decomposed by fungi, which have a higher assimilation efficiency than the bacteria that dominate the decomposition processes of residue mixed into the soil.; POM consists of partially decomposed plant residues and is considered to be the first intermediate pool in the decay continuum between crop residue (and humified stable OM.; After 360 days 66% of the 14C contained in the surface residue .. had been respired as CO2, 11% remained in the residue on the soil surface and 16% was in the soil. Most of [it] .. was associated with the silt+ clay fraction. Only a small amount .. accrued in the POM ..; In comparison, 56% H of the root-derived 14C in the soil was evolved as CO2 and 42% remained in the soil. .. the beneficial effects of no-till on SOC accrual are primarily due to the increased retention of root-derived C in the soil. |
| 1423 | Gale, W.J., Cambardella, C.A. & Bailey, T.B. | Surface-residue- and root-derived carbon in stable and unstable aggregates | 2000 | Roots & Rhizodeposition; Soil Organic Carbon; Tillage | Journal | Soil Sci. Soc. Am. J.; 64 (1); 196-201 | English | Hardcopy:Partial | Expt. to subject a soil that had been under continuous maize and conventional tillage for 30 years to simulated zero tillage | x; We observed a rapid loss of 14C from both the surface residue and coarse roots .. and an increase in aggregate stability until day 180 [followed by a decline]. This suggests that microbial binding agents produced during the decomposition of the surface residue and/or roots will result in increased aggregate stability under no-till. This increase is temporary, ostensibly because the microbial `products are labile and subject to further decomposition.; The 14C concentrations in .. microaggregates .. generally increased throughout the incubation.; .. root-derived C has an important role in the stabilisation of small macroaggregates, whereas new C inputs from surface residue do not contribute significantly to macroaggregate stability under simulated no-till. |
| 1424 | Gale, W.J., Cambardella, C.A. & Bailey, T.B. | Root-derived carbon and the formation and stabilisation of aggregates | 2000 | Roots & Rhizodeposition; Soil Organic Carbon; Tillage | Journal | Soil Sci. Soc. Am. J.; 64 (1); 201-207 | English | Hardcopy:Partial | Expt. to subject a soil that had been under continuous maize and conventional tillage for 30 years to simulated zero tillage | .. new micro aggregates form around decomposing pieces of root-derived POM inside existing macroaggregates ..; After day 180 .. the stability of the macroaggregates begins to decline, as evidenced by the release of large microaggregates that contain cores of new root-derived POM. Some of the microaggregates .. become unstable after about 1 year and release labile POM C that is now available for further decomposition. |
| 1035 | Galvez, L., Douds, D.D., Drinkwater, L.E. & Wagoner, P. | Effect of tillage and farming systems on VAM fungus populations and mycorrhizas and nutrient uptake of maize | 2001 | Organic Farming; Soil Microorganisms; Tillage | Journal | Plant Soil; 228 (2); 299-308 | English | Hardcopy:Partial | The effect of tillage and low-input v. conventional farming on vesiculararbuscular mycorrhizal fungi in maize is examined. Fungal spore populations, mycorrhiza formation and nutrient utilisation by the maize were studied in ploughed, chisel-disced and no-tilled soil in conventional and low-input systems. | VAM fungi play a key role in the nutrition, water relations and pest resistance of host plants.; Damage to [their] hyphal network by tillage and soil disturbance may contribute to .. reduction of P uptake by plants.; Soils under low-input management had higher VAM fungus spore populations than soils under conventional management. Spore populations and colonisation of maize roots by VAM fungi were higher in no-tilled soil than in .. ploughed or chisel-disced soil. .. This benefit of enhanced VAM fungus colonisation, particularly in the low-input system in the absence of effective weed control and with likely lower soil temperatures, did not translate into enhanced growth and yield. |
| 458 | Gami, S.K., Ladha, J.K., Pathak, H., Shah, M.P., Hobbs, P.R., Pasuquin, E., Hobbs, P.R., Joshi, D. & Mishra, R. | Long-term changes in yield and soil fertility in a twenty-year rice-wheat expt. in Nepal | 2001 | Soil (General) | Journal | Biol. Fertil. Soils; 34; 73-78 | English | Hardcopy:Full | The results of an expt. with a rice-wheat rotation under various amendment regimes, namely, no fertiliser, FYM only, FYM plus inorganic N, chopped wheat straw plus inorganic N, and various combinations of inorganic N, P and K fertilisers. Owing to poor husbandry the yields generally were only about half what would normally be expected in the region. The poorest mean annual yields of rice were obtained with no fertiliser, followed by 50 kg/ha of inorganic N only, followed by 4 Mg/ha FYM only. The highest mean annual yield of rice was obtained with the highest application of inorganic fertiliser, namely, 100 N, 13.1 P and 25 K kg/ha. In the case of wheat, the lowest yield was again with no fertiliser, followed by the plot with FYM only. The highest yield was with the same NPK application as with the rice. Total soil C & N did not change significantly on any of the plots over the period of the expt. The treatment with FYM so the greatest annual accumulation of both C & N. There was no significant change in the soil BD and no significant difference in soil BD between the different amendments. | The production of both [rice and wheat] has increased markedly with the introduction of modern technologies based on early maturing, N-responsive, semidwarf cultivars. .. There are indications that the yields .. have declined. The depletion of soil nutrients, particularly K, is reported to be a possible cause of such a decline. |
| 1721 | Gamliel, A., Austerweil, M. & Kritzman, G. | Non-chemical approach to soilborne pest management - organic amendments | 2000 | Uncategorised | Journal | Crop Prot.; 19; 847-753 | English | PDF:Full | ||
| 380 | Garcia, S., Latge, J.P., Prevost, M.C. & Leisola, M. | Wood degradation by white-rot fungi: cytochemical studies using lignin peroxidase-immunoglobulin-gold complexes | 1987 | Lignin and CBW | Journal | Appl. Environ. Microbiol.; 53 (10); 2384-2387 | English | Hardcopy:Full | Lab. expt. to study the degradation of various wood and sawdust samples by 4 different white-rot fungi | Lignin peroxidase was located mainly intracellularly in naturally decayed wood ..; .. lignin peroxidase can oxidise lignin through one-electron transfer mediators .. no direct contact is necessary between the enzyme and the lignin. |
| 1224 | Garcia-Gil, J.C., Plaza, C., Soler-Rovira, P. & Polo, A. | Long-term effects of municipal solid waste compost application on soil enzyme activities and microbial biomass | 2000 | Compost & Biocontrol; Soil Microorganisms | Journal | Soil Biol. Biochem.; 32; 1907-1913 | English | Hardcopy:Partial; Wordperfect:Full | A 9-year field expt. to study the effects of four different treatments x(municipal solid waste compost at 20 or 80 t ha-1, FYM at 20 t ha-1 and chemical fertiliser) on soil enzyme activities and microbial biomass. These amendments increased soil microbial biomass in the order 80t MSW > FYM > 20t MSW > chemical. Oxidoreductase enzyme activity was greatly enhance by all organic amendments (FYM > MSW), but hydrolase enzymes showed varying response. | |
| 731 | Garcia-Oliva, F., Martinez Lugo, R. & Maass, J.M. | Long-term net soil erosion as determined by 137Cs redistribution in an undisturbed and perturbed tropical deciduous forest ecosystem | 1995 | Miscellaneous; Soil (General) | Journal | Geoderma; 68 (1/2); 135-147 | English | Hardcopy:Partial | Cs-137 was used to estimate the rate of soil erosion. On pasture, following slash-and-burn, the rates ranged from zero to 23 Mg/ha/yr, with an average of 9 Mg/ha/yr. | The half-life of 137Cs is relatively long (30.2 years) and its concentration in soil world-wide is the result of nuclear testing. The most important period of 137Cs fall-out occurred during 1962-1964. .. A significant amount of 137Cs was released .. following the accident at the Chernobyl nuclear power station in 1986. .. Radio-caesium is strongly adsorbed by fine soil particles and OM.; .. the first year after slash-and-burn is critical for susceptibility to soil erosion. Based on .. the present study, the top 5 cm. of soil could be removed in only 25 years. |
| 732 | Garcia-Oliva, F., Sanford, R.L. & Kelly, E. | Effects of slash-and-burn management on soil aggregate organic C & N in a tropical deciduous forest | 1999 | Soil Organic Carbon; Sustainability | Journal | Geoderma; 88 (1/2); 1-12 | English | Hardcopy:Partial | An expt. to test the effect on SOM of burning forest to convert it to pasture. | Fire did not destroy macroaggregates but their associated C was lost by combustion. This C reduction disrupted soil macroaggregate stabilisation .. large macroaggregates decreased by 53% during the first growing season [because of] three processes: .. large macroaggregates are preferentially removed by soil erosion, .. the breakdown of macroaggregates by raindrop impact .. the breakdown of aggregates by slaking .. periods of intense rainfall occur[ing] after soils have dried out.; .. the organic C content associated with large macroaggregates comprised approximately 50% of the total sand-free sol C content in forest soil. Large macroaggregates, however, had only 20% of the total C after the first growing season and the highest percentage of SOC was associated with microaggregates. |
| 640 | Garnier, P., Neel, C., Aita, C., Recous, S., Lafolie, F. & Mary, B. | Modelling carbon and nitrogen dynamics in a bare soil with and without straw incorporation | 2003 | Soil Organic Carbon; Soil N Dynamics | Journal | Eur. J. Soil Sci.; 54; 555-568 | English | Hardcopy:Partial; PDF:Full | Expt. to compare the C & N dynamics in soils untreated and treated with straw | The microbial population is split into an autochthonous biomass that decomposes humified OM & a zymogenous biomass that decomposes fresh & soluble OM. |
| 641 | Garnier, P., Neel, C., Mary, B. & Lafolie, F. | Evaluation of a nitrogen transport and transformation in a bare soil | 2001 | Soil Organic Carbon; Soil N Dynamics | Journal | Eur. J. Soil Sci.; 52 (2); 253-268 | English | Hardcopy:Partial | Modelling the transformation and transport of N in the soil | .. biological factors (the autochthonous biomass decomposition rate .. and the temperature factor coefficient of HOM decomposition ..) affected mostly N mineralisation and had very little effect on nitrate leaching. .. the initial boundary conditions (potential evapotranspiration and initial nitrate content in the first layer) and the ..hydraulic conductivity function had a great influence on nitrate leaching but had no influence on nitrate mineralisation. |
| 515 | Gasser, M.O., N'dayegamiye, A. & Laverdière, M.R. | Short-term effects of crop rotations and wood-residue amendments on potato yields and soil properties of a sandy loam soil | 1995 | Lignin and CBW; Potato Growing | Journal | Can. J. Soil Sci.; 75 (3); 385-390 | English | Hardcopy:Partial | Field trials on the use of various organic soil amendments on a sandy loam soil xbefore a potato crop. Barley stubble gave the best yield and best quality potato crop. There was not much difference between the other amendments. | The .. size of the tree clippings .. varied from 6 to 14 mm, with only 13% of the material being <2 mm .. thereby resulting in a small soil interface, which can limit its attack by microorganisms.; .. wood residue materials with higher lignin contents than the crop residues should degrade more slowly and therefore contribute more to soil humus formation. .. [but] ligneous materials did not appear to significantly improve the structural stability of the soil. This .. contrasts with observations presented on other organic amendments such as manure. |
| 1225 | Gathumbi, S.M., Cadisch, G. & Giller, K.E. | 15N natural abundance as a tool for assessing N2-fixation of herbaceous, shrub and tree legumes in improved fallows | 2002 | Green Manure; Soil N Dynamics | Journal | Soil Biol. Biochem.; 34 (8); 1059-1071 | English | Hardcopy:Partial; Wordperfect:Full | Expt. to test the effectiveness of 15N natural abundance methods for assessing N fixation of leguminous trees and shrubs | @; Most tested tree/shrub legumes showed no 15N discrimination during N2-fixation .. Significant 15N isotopic discrimination occurred during translocation of fixed N, which resulted in 15N depletion in shoots compared with roots and nodules, which were 15 |
| 424 | Gaudinski, J., Trumbore, S.E., Davidson, E. & Zheng, S. | Soil carbon cycling in a temperate forest: radio-carbon-based estimates of residence times, sequestration rates and partitioning of fluxes | 2000 | Energy Resources; Greenhouse Gases; Soil Organic Carbon | Journal | Biogeochemistry (Dordr.); 51; 33-69 | English | Hardcopy:Partial; PDF:Full | Estimating the rate of carbon accumulation in a temperate forest | @; Soil respiration was partitioned into two components ..: recent photosynthate which is metabolised by roots and microorganisms within a year of initial fixation (Recent-C) and C that is respired during microbial decomposition of SOM that resides in the |
| 329 | Gavett, E.E. | Agriculture and energy use | 1973 | Energy in Agriculture | Journal | Ann. Meet. Amer. Agric. Econ. Assoc.; ; | English | [cited in Fluck and Baird (1980), p.112] To emphasise the infeasibility of a return to draft animals Gavett stated that 61 million draft animals [horses or mules ?] would be required to power today's U.S. agriculture and that these draft animals would consume the feed produced from over 73 million hectares of arable land or almost half the U.S. arable land. This means that the average draft animal requires 1.2 ha of land to feed it. | ||
| 642 | Gerzabek, M.H., Antil, R.S., Koegel-Knabner, I., Knicker, H., Kirchman, H. & Haberhauer, G. | How are soil use and management reflected by soil organic matter characteristics: a spectroscopic approach | 2006 | Soil Organic Carbon | Journal | Eur. J. Soil Sci.; 57; 485-494 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the changes in SOM due to different land-uses (arable & grassland) and treatments (FYM & chemical fertiliser) | .. increasing OC contents of the silt-sized fractions were not matched by a linear increase of silt-sized aggregates. This indicated saturation of the aggregates with OC & a limited capacity of particles to protect OC physically. .. The silt-sized fractions contained the largest SOM pool & .. were qualitatively more influenced by the plant residue versus manure input than the clay fractions. |
| 1425 | Gerzabek, M.H., Haberhauer, G. & Kirchmann, H. | Soil organic matter pools and carbon-13 natural abundance in particle-size fractions of a long-term agricultural field expt. receiving organic amendments | 2001 | Green Manure; Organic Farming; Soil Organic Carbon | Journal | Soil Sci. Soc. Am. J.; 65 (2); 352-358 | English | Hardcopy:Full | Expt. to study the distribution of native and amendment-derived C in plots from a 42-yr trial under four different treatments: green manure, FYM, sewage sludge and peat. Organic C in the silt-sized particles (2-63 m) is the main medium-term C sink, as it increased with increasing bulk-soil SOC, whereas the contribution of clay-sized particles (<2m) decreased. The proportion of SOC originating from amendments decreased (from 70% to 30%) with particle size, the sand fraction being the most sensitive to differing treatments. The C content went down in the unfertilised controls and up by 21%, 50%, 72% and 113% in the green manure, FYM, sewage sludge and peat treatments respectively. | The annual C turnover through the terrestrial biosphere amounts to 60 Gt, which is around 9% of the atmospheric C pool.; .. SOC content increased with diminishing particle size, whereas the C/N ratio decreased. .. OM recently introduced into soil is predominantly located in larger aggregates. .. macroaggregates (<250 m) can be destroyed by agricultural practices, whereas microaggregates cannot.; Microbial and chemical transformation during humification 0enriches 13C in silt and clay. Consequently, the introduction of organic manures whose 13C enrichment differs from that of the soil .. enables the C derived from amendments to be traced into the existing SOC pool. |
| 643 | Gerzabek, M.H., Pichlmayer, F., Kirchmann, H. & Haberhauer, G. | The response of soil organic matter to manure amendments in a long-term expt. at Ultuna, Sweden | 1997 | Green Manure; Organic Farming; Soil Organic Carbon | Journal | Eur. J. Soil Sci.; 48 (2); 273-282 | English | Hardcopy:Partial | 40-year field expt. to study the changes in OM as a result of manure amendments applied at a standard rate of 2000 kg C per ha per year: fallow, green manure, FYM, peat and chemical fertiliser with no N. | Fallow and mineral fertiliser without N led to a significant decrease in SOM, green manure maintained the SOM content and peat increased the SOM content significantly. The stable portion of the added organic materials .. was 12.8, 27.3 and 56.7% for green manure, animal manure and peat respectively. This was reflected [in the] half-lives of organic C originating from the amendments between 3.0 (green manure) and 14.6 years (peat).; Total losses of C were greatest from the green manure treatment .. |
| 860 | Ghidey, F. & Alberts, E.E. | Runoff and soil losses as affected by corn and soybean tillage systems | 1998 | Soil (General); Tillage | Journal | J. Soil Water Conserv.; 53 (1); 64-70 | English | Hardcopy:Full | A comparison of water run-off and soil erosion under conventional and zero tillage during maize and soya bean cultivation. Zero tillage performed better in respect of soil loss and worse in respect of water run-off compared with conventional tillage. Soil loss figures varied between 0.02 Mg/ha at the crop maturing stage under zero tillage and 7.33 Mg/ha for a seedbed under conventional tillage. The cumulative soil loss over the ten years of the expt. were: 170 Mg/ha for conventional tillage and 25 Mg/ha for zero tillage. | .. the study showed that (1) cropping had little effect on run-off and soil loss and (2) no-till significantly increased run-off and substantially reduced soil loss when compared to the conventional method. |
| 220 | Giampietro, M. | Socioeconomic constraints to farming with biodiversity | 1997 | Sustainability | Journal | Agric. Ecosyst. Environ.; 62; 145-167 | English | Hardcopy:Partial | The biodiversity of agricultural crops is reviewed. A radical reduction in the number of plant and animal species used as food has occurred as a result of the pressure for greater agricultural productivity, which is an inevitable consequence of the pattern of development adopted by western civilisation. | .. more than 90% of the world food supply is currently derived from only fifteen plant and eight animal species, and 60% of the world food supply from only rice, corn [maize] and wheat. .. also the genetic diversity within cultivated species .. in the next ten years 90% of the existing genetic diversity within the main crops (rice, wheat, corn [maize], sorghum, etc.) is at serious risk of disappearing.; .. a reduced diversity in the plants and animals used as our food base carries serious risks ..; Alternative agricultural techniques based on traditional solutions that use more biodiversity must .. be revisited ..; Agriculture .. cannot be defined only in terms of economic efficiency in food production.; .. most countries are moving toward high-energy-input and labour-saving technologies. Moving away from this path of technological development .. would be required to preserve and enhance biodiversity use in agriculture .. |
| 221 | Giampietro, M. & Pimentel, D. | Assessment of the energetics of human labour | 1990 | Energy in Agriculture; Labour and Animal Power | Journal | Agric. Ecosyst. Environ.; 32 (3-4); 257-272 | English | Hardcopy:Partial | The energy cost of human labour is considered on a societal level instead of the usual individual level. | The shift from the individual level to the societal level provides a new perspective when assessing the energetic efficiency of farming. For example, the power level of the system becomes a new and important parameter to consider. |
| 180 | Giampietro, M., Bukkens, S.G.F. & Pimentel, D. | Models of energy analysis to assess the performance of food systems | 1994 | Energy in Agriculture | Journal | Agric. Sys.; 45; 19-41 | English | Hardcopy:Partial | Energy analysis can be used as a tool to assess the impact of food system activities on society and the environment. It can be used (alongside economic indicators) to quantify the performance of a food system, including not only the direct costs of production and of post-harvest operations (processing and distribution), but also the indirect costs related to the economic efficiency of society and to the ecological efficiency of ecosystems. The cost to society is calculated on the basis of the opportunity cost of human labour. | 100,000 kcal [= 420 MJ] is the opportunity cost of one hour of US labour assessed at the level of society. .. For traditional pre-industrial societies the opportunity cost of human labour can be estimated in the range of 3000-3500 kcal/hour [12.5-15 MJ] .. |
| 1630 | Gibson, M. | Can stockless organic systems really be sustainable? | 2004 | Stockless Farming; Sustainability | Book | Gibson, M.; Can stockless organic systems really be sustainable?; | English | Hardcopy:Full | Review of stockless organic research and enterprises (Iain Tolhurst's) | .. a significant increase in stockless system would be the most economical, sustainable and least harmful use of the earth's increasingly pressured food producing resources. |
| 149 | Gifford, R.M. | Energy in different agricultural systems: renewable and non-renewable resources (part) | 1984 | Energy in Agriculture | Book | Stanhill, G. (ed.); Energy and Agriculture; 84-112 | English | Hardcopy:Partial | Solar energy use in agriculture - direct and indirect (in the form of biomass, fossil fuels, etc.). Energy shortages, caused (in the Third World) by lack of resources or (in the industrialised countries) by eventual scarcity of fossil fuels, can only to a limited degree be compensated by use of renewable resources like biomass and by improvements in the efficiency of use of existing fuels | The single most important energy objective in world agriculture is to maximise the amount of solar light intercepted by crop and pasture leaves. This requires skilled and timely management, crop breeding and support energy inputs. .. As crude petroleum runs out over the next century, liquid fuels derived from coal are likely to be the most abundant and inexpensive substitutes .. The urgency to diversify into [alternative] energy resources will be increased if the H climatic impact of rising atmospheric CO2 concentration is identified as being a serious concern. However, there is no general prospect of farms providing biomass for conversion to liquid fuels on sufficient scale to match the present level of petroleum consumption by the cities. Furthermore, there is risk that biomass fuel production will compete with food production and exacerbate soil erosion. |
| 587 | Gilland, B. | Energy for the 21st century: an engineer's view | 1990 | Energy Resources | Journal | Endeavour; 14 (2); 80-86 | English | Hardcopy:Partial | Energy consumption worldwide, CO2 flux and renewable energy sources are considered. Predictions are made of the magnitude of future alternative energy resources. If fully exploited, hydroelectric power could supply all the present world's energy consumption. All other renewable resources together would supply about the same amount again. | .. the fast reactor will be the only means of maintaining power production when the inevitable decline in fossil fuel production sets in. |
| 16 | Giller, K.E. & Cadisch, G. | Driven by nature: a sense of arrival or departure? | 1997 | Soil Organic Carbon | Book | Cadisch, G. & Giller, K.E. (eds.); Driven by Nature: Plant Litter Quality and Decomposition. C.A.B. International; | English | Hardcopy:Partial; Wordperfect:Full | Review of the part played by plant litter in regulating the SOM content and the rate and outcome of its decompostion | Are polyphenols a fast-route to SOM, due to their ability to complex proteins and carbohydrates? The stability of protein-polyphenol complexes formed during early decomposition ... have indicated that the protein N is not released over periods of several months, once it has been complexed by polyphenols. The degradative capacity of basidiomycetes in attacking polyphenol- and lignin-rich litter in forest systems is highlighted below, but such fungi are not abundant in many agricultural systems. |
| 1036 | Giller, K.E. & Cadisch, G. | Future benefits from biological nitrogen fixation: an ecological approach to agriculture | 1995 | Green Manure; Stockless Farming; Soil N Dynamics | Journal | Plant Soil; 174; 255-277 | English | Hardcopy:Partial | Review of the applications and possibilities of N-fixing leguminous plants | x; .. inoculation is the approach most likely to result in maximising N2-fixation.; Unfortunately in many Africa countries, where large potential benefits might be accrued from BNF [biological N fixation], the basic inputs such as P fertilisers necessary to allow N2-fixation to work are beyond the reach of the farmers. |
| 347 | Giller, K.E., Beare, M.H., Lavelle, P., Izac, A.M.N. & Swift, M.J. | Agricultural intensification, soil biodiversity and agroecosystem function | 1997 | Soil (General); Sustainability | Journal | Appl. Soil Ecol.; 6; 3-16 | English | Hardcopy:Partial; PDF:Full | Review of ideas relating to the possible connection between soil biodiversity and the productivity of agroecosystems | A popular assumption is that anthropogenic interference in nature results in a loss of biological diversity. .. Yet .. there is little detailed evidence for agricultural intensification resulting in loss of biodiversity in soil.; .. there no clear link between agricultural intensification and biodiversity ..; There is evidence that ecosystem function may be significantly impaired by loss of soil biodiversity ..; The use of broad-spectrum pesticides .. has both targeted and non-targeted effects on the composition and diversity of soil biological communities. While the targeted effects are often well characterised, the non-targeted effects, such as those reported for earthworms, microarthropods and certain beneficial (e.g. predatory) insects, are poorly known .. |
| 861 | Gilley, J.E. & Doran, J.W. | Tillage effects on soil erosion potential and soil quality of a former Conservation Reserve Program site | 1997 | Soil (General); Tillage | Journal | J. Soil Water Conserv.; 52 (3); 184-188 | English | Hardcopy:Full | Three CRP plots (one undisturbed, one 4 days after initial cultivation and one nine months after initial cultivation) were compared with a plot of long-term arable land in respect of erosion potential and soil quality. The indices of erosion potential were surface cover, run-off, sediment concentration in the run-off and soil loss. the indices of soil quality were SOM, BD, water content, mineralisable N content, electrical conductivity, pH and extractable phosphorus content. | A substantial reduction in the amount of SOC .. occurred nine months following tillage. .. no significant difference in run-off was found between the undisturbed CRP and tilled treatments. Soil loss values were minimal on the undisturbed CRP and the plots that had been recently tilled. .. soil loss on plots that had been tilled nine months previously were similar to values obtained when the area had been used as cropland. Soil physical, chemical and biological properties were also greatly influenced by tillage and fallowing of the former CRP site. |
| 862 | Gilley, J.E., Doran, J.W., Karlen, D.L. & Kaspar, T.C. | Run-off, erosion and soil quality characteristics of a former Conservation Reserve Program site | 1998 | Soil (General); Tillage | Journal | J. Soil Water Conserv.; 54 (1); 189-193 | English | Hardcopy:Full | A comparison of soil qualities between grassland that had been undisturbed for ten years and arable land under different tillage regimes. Zero tilled arable land showed better soil qualities in certain respects, comparable with those of the undisturbed grassland. The soil loss was much greater from the autumnploughed land than from the spring-ploughed. | Substantial soil loss was measured from the mouldboard plough treatments, but no significant difference in the erosion rates were found between the undisturbed [grassland] and no-till management systems. No-till management maintained levels of soil quality similar to those of [undisturbed grassland] by preserving soil structural integrity and reducing losses of SOM associated with tillage. |
| 819 | Ginting, D., Kessavalou, A., Eghball, B. & Doran, J.W. | Greenhouse gas emissions and soil indicators four years after manure and compost applications | 2003 | Compost & Biocontrol; Greenhouse Gases | Journal | J. Environ. Qual.; 32; 23-32 | English | Hardcopy:Partial; PDF:Full | Expt. to quantify the emission of greenhouse gases from soil four years after FYM and compost application had stopped | The average annual C input in the [control] and [chemically fertilised] plots were similar to soil CO2-C emission (4.4 and 5.1 Mg C ha-1 yr-1, respectively). Manure and compost resulted in positive C & N balances in the soil four years after application. Fluxes of CH4-C and N2O-N were nearly zero, which indicated that the residual effects of manure and compost four years after application had no negative influence on soil C & N storage and global warming. Residual effects of compost and manure resulted in 20 to 40% higher soil microbial biomass C, 42 to 74% higher potentially mineralisable N and 0.5 unit higher pH compared with the FRT treatment.; Most of the CO2-C fluxes were from soil microbial and invertebrate activities. .. contribution of root and root-induced respiration to the total CO2-C fluxes ranged from 10 to 50% of total CO2-C emitted.; The [chemically] fertilised plots had lower MBC [microbial biomass C], PMN [potentially mineralisable N] and soil pH compared with the manure and compost plots. |
| 1637 | Giri, G.S. | Surface/relay planting: an option for planting wheat on time in the lower wetlands of the Tarai, Nepal | 1997 | Miscellaneous; Mulch | Book | ; Proceedings of the Rice–Wheat Research End-of-Project Workshop 1–3 October 1997, Hotel Shangri-La, Kathmandu, Nepal; 57-62 | English | Hardcopy:Full | Field-scale and on-farm research to study various methods of growing wheat after rice, comparing relay sowing, surface seeding and farmers' current practice (ploughing after rice harvest). Various techniques were tested, including surface sowing, relay sowing, pre-soaking the seed, pre-irrigating the soil, sowing into various depths of rice stubble and covering the seed with harvested rice for a few days. | The wheat crop relayed into standing rice produced the highest yield, followed by surface seeding [after rice harvest ?] and farmers' practice.; Wheat seed was soaked .., treated with fresh cow dung [to repel birds] and broadcast into the standing rice crop .. three days before harvest. After the rice was harvested, the plots were uniformly covered with the harvested rice.; The farmers' practice consisted of four ploughings followed by two plankings.; Covering seeds with rice for 9 days produced more effective tillers than the rest of the covering treatments [0, 3 and 6 days]. .. an increase in the duration of seed cover increased yield.; Excess soil moisture is the most critical factor for the success of zero tillage wheat cultivation .. the effect of soaking the seed became negligible when [the] soil had sufficient moisture for crop establishment ..; .. wheat yield was positively correlated to rice stubble height: the higher the rice stubble, the higher the yield. |
| 1638 | Giri, G.S. | Effect of rice and wheat establishment techniques on wheat grain yield | 1997 | Miscellaneous | Book | ; Proceedings of the Rice–Wheat Research End-of-Project Workshop 1–3 October 1997, Hotel Shangri-La, Kathmandu, Nepal; 66-68 | English | Hardcopy:Full | Trial-plot research to test the effect of rice establishment techniques on the following wheat crop and to compare various wheat establishment techniques. Rice was broadcast into a dry seed bed and into a wet one, drilled with a machine and transplanted. The following wheat crop was better, in terms of tillering, yield, thousand-grain weight and total biomass, after the dry broadcast rice than after any of the other rice establishment methods. In the wheat trials the surfaceseeded wheat had the highest thousand-grain weight, but the machine-drilled crop was better in all other respects. Its yield exceeded by about 10% that of the surface-seeded wheat. | |
| 382 | Girvan, M., Bullimore, J., Ball, A., Pretty, J. & Osborn, M. | Responses of active bacterial and fungal communities in soils under winter wheat to different fertiliser and pesticide regimens | 2004 | Soil Microorganisms | Journal | Appl. Environ. Microbiol.; 70 (5); 2692-2701 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the effect on soil microbial communities of differing levels of fertiliser and pesticide application | Microbial community structure was primarily determined by season, and the seasonal trends were similar for the fungal and bacterial components.; .. the different fertilisation regimens had the greatest effects on bacterial & fungal community structure, causing short-term increases in total culturable bacterial counts. .. a decrease in the overall diversity & heterogeneity of the bacterial community, but not the fungal community, was observed. Pesticide application did not reduce the total bacterial numbers or the active bacterial diversity, but it did affect the community structure, possibly due to bacterial pesticide degradation. Smaller management effects were observed in the fungal population. |
| 381 | Girvan, M., Bullimore, J., Pretty, J., Osborn, M. & Ball, A. | Soil type is the primary determinant of the composition of the total and active bacterial communities in arable soils | 2003 | Organic Farming; Soil Microorganisms | Journal | Appl. Environ. Microbiol.; 69 (3); 1800-1809 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the factors affecting soil microbial communities in soils under different management systems | .. soil type is the overriding factor in community determin'ns at these sites, followed by the planting of specifically leguminous crops rather than other mgmt practices.; Org. farming did not necessarily result in elevated OM levels; instead a strong assoc'n with increased nitrate availability was apparent. |
| 308 | Glasby, G.P. | Entropy, pollution and environmental degradation | 1988 | Sustainability | Journal | Ambio; 17 (5); 330-335 | English | Hardcopy:Full | Energy consumption by human activity necessarily involves environmental degradation and increase in entropy. Humans use the energy of nature to produce order (lower entropy). In the process part of nature's energy is dissipated and its entropy increases. So environmental degradation is a necessary part of human activity. Thus our own success as a species is our biggest threat. | ..human development must pass into a state of ecological balance if its is not to end with the Pleistocene.; We live in a small bubble of order. .. This ordering constitutes the capital of low entropy with which our planet is endowed. .. man is living off this `capital' of low entropy.; The energy needed to drive the entropy reduction is supplied almost entirely by radiation from the sun.; .. activity per se necessarily leads to increased disorder ..; ..our massive assault against the biosphere, along with the availability of energy, [is] the main determinant of our potential rate of industrial expansion. |
| 975 | Glaser, B., Balashov, E., Haumaier, L., Guggenberger, G. & Zech, W. | Black carbon in density fractions of anthropogenic soils of the Brazilian Amazon region | 2000 | Soil Organic Carbon | Journal | Org. Geochem.; 31 (7-8); 669-678 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the concentration and distribution of black C in Brasilian Terra Preta soils | .. SOM of Terra Preta soils consists of up to 35% of black C throughout the deep A horizons. In the surrounding Oxisols black C occurs only in the first few centimetres of the soil profile with concentrations of up to 14% of the SOM. 14C ages of black C of about 1000-1500 years suggest a high stability ..; .. black C in soils can be found as particulate, unprotected, physically trapped and as oxidatively altered forms that are complexed with minerals.; The highest concentrations and absolute amounts of black C were identified in the light fraction, indicating the particulate nature of black C.; [hence]; .. a major part of black carbon is not chemically stabilised but intrinsically refractory. |
| 927 | Glaser, B., Haumaier, L., Guggenberger, G. & Zech, W. | The 'Terra Preta' phenomenon: a model for sustainable agriculture in the humid tropics | 2001 | Soil Organic Carbon | Journal | Naturwissenschaften; 88; 37-41 | English | Hardcopy:Full; PDF:Full | Study of a certain black-earth-like soil found in central Amazonia, known as Terra Preta | More likely than natural fires as a source of black C in Terra Preta soils are the low-heat smouldering domestic fires commonly used by the native population for cooking and heating.; In the Brazilian Amazon region dense populations once successfully farmed poor oxisols for at least 2,500 years, leaving behind the rich Terra Preta soils, before being displaced by Europeans; Terra Preta soils may be derived from oxisols by enrichment with black C from residues of incomplete burning produced by the early Amerindian population. Due to the highly aromatic structure of black C, it is assumed be chemically and microbially stable and persists in the environment over centuries or millennia. Thus, a part of the labile C pool in the biomass has been converted into a stable SOM pool.; .. in contrast with burning, charring not only prevents large amounts of CO2 from being released into the atmosphere but also provides the soil with a persistent SOM pool rich in nutrient-holding capacity .. |
| 976 | Gleixner, G., Poirier, N., Bol, R. & Balesdent, J. | Molecular dynamics of organic matter in a cultivated soil | 2002 | Lignin and CBW; Soil Organic Carbon | Journal | Org. Geochem.; 33; 357-366 | English | Hardcopy:Partial; PDF:Full | Field expt. to assess the residence time of maize-derived OM in soil | Most pyrolysis products from the maize were derived from polysaccharides and lignins and were not detected in soils. However polysaccharide-derived products @were major pyrolysis products in soils.; *; .. the same 18 pyrolysis products were identified in both cultivated soils.. Most of them were related to polysaccharides, proteins or cpds from multiple sources. .. the majority of pyrolysis products in the maize soil originated from a slowly degrading C pool (between 10 and 100 years). Pyrolysis products from N-containing precursors, i.e. proteins, amino acid moieties or chitin, and polysaccharides had high residence times of about 50 yrs. The results confirm .. that N-containing moieties can be preserved during soil decompos'n & humification processes. Moreover, our results suggest that recycling of amino acids & carbohydrates plays a major role in this stabilisation. The virtual lack of lignin biomarkers demonstrates that lignin is severely biodegraded and is probably not present any more in its initial form. |
| 848 | Goicoechea, N., Merino, S., S1nchez-D1az, M. | Arbuscular mycorrhizal fungi can contribute to maintain antioxidant and carbon metabolism in nodules of Anthyllis cytisoides L. subjected to drought | 2004 | Green Manure; Soil Microorganisms | Journal | J. Plant Physiol.; 162; 27-35 | English | Hardcopy:Partial; Wordperfect:Full | Field expt. to test whether AM fungi could help a legume (a Mediterranean relative of kidney vetch) to maintain N fixation during drought | .. long periods of water deficit decrease the diffusion rate of P and consequently also decrease the BNF.; .. the limited diffusion rate of nutrients, particularly p, from the soil matrix to the absorbing surface when soil moisture declines, negatively affects nodulation and BNF.; .. a low soil water content .. accelerated the senescence of nodules in both non-mycorrhizal and mycorrhizal plants. However, while total soluble protein, leghaemoglobin (Lb) content, as well as carbon and antioxidant metabolism significantly decreased in nodules from non-mycorrhizal A. cytisoides subjected to drought, nodules from stressed mycorrhizal plants maintained Lb levels, showed greater rates of carbon metabolism, and exhibited higher enzymatic activities related to the removal of reactive oxygen species. |
| 1702 | Goklany, I.M. | The ins and outs of organic farming | 2002 | Uncategorised | Journal | Science; 298; 1889-1891 | English | PDF:Full | ||
| 733 | Golchin, A., Baldock, J.A., Clarke, P., Higashi, T. & Oades, J.M. | The effects of vegetation and burning on the chemical composition of soil organic matter of a volcanic ash soil as shown by 13C NMR spectroscopy: II. Density fractions | 1997 | Soil Organic Carbon | Journal | Geoderma; 76; 175-192 | English | Hardcopy:Partial | Study on three Japanese soils derived from volcanic ash | .. both free and occluded POM may include considerable amounts of charcoal and charred plant residues where vegetation burning was practised. Assuming no or a limited degradation of charcoal with time through microbial or inorganic reactions, the presence of charcoal in soils not only changes the chemistry of SOM (e.g. increase in aromaticity) .. but can also change its mean turnover times. |
| 734 | Golchin, A., Clarke, P., Baldock, J.A., Higashi, T., Skjemstad, J.O. & Oades, J.M. | The effects of vegetation and burning on the chemical composition of soil organic matter of a volcanic ash soil as shown by 13C NMR spectroscopy: I. Whole soil and humic acid fraction | 1997 | Soil Organic Carbon | Journal | Geoderma; 76; 155-174 | English | Hardcopy:Partial | Study on three Japanese soils derived from volcanic ash | On site I, where grasses were still burned annually, SOM and humic acid fraction contained a greater proportion of aromatic and carbonyl carbons compared to the other sites.; Invasion of grassland by forest resulted in a decrease in C aromaticity and an increase in alkyl C content of the soil and humic acid fraction. |
| 403 | Golchin, A., Clarke, P., Oades, J.M. & Skjemstad, J.O. | The effects of cultivation on the composition of organic matter and structural stability of soils | 1995 | Soil Organic Carbon; Tillage | Journal | Aust. J. Soil Res.; 33 (6); 975-993 | English | Hardcopy:Partial | Lab. expt. to compare the composition of tilled and untilled soils | Differences in the chemical composition of OC between cultivated and uncultivated soils resided mostly in organic materials occluded within aggregates.; .. the virgin sites and sites that had been under long-term pasture had a greater aggregate stability than the cultivated sites.; .. only part of soil C or carbohydrate is involved in aggregate stability. The fractions of C and O-alkyl C present in the form of POM occluded within aggregates were better correlated with aggregate stability. |
| 404 | Golchin, A., Oades, J.M., Skjemstad, J.O. & Clarke, P. | Soil structure and carbon cycling | 1994 | Soil Organic Carbon | Journal | Aust. J. Soil Res.; 32 (5); 1043-1068 | English | Hardcopy:Partial | Lab. study to investigate and model the changes undergone by OM during decomposition in various native soils | .. OM enters the soil, is enveloped in aggregates and eventually is incorporated into microbial biomass and metabolites and associated with clay minerals. .. This model indicates a major role for carbohydrate-rich plant debris in formation and stabilisation of microaggregates. |
| 1005 | Goldemberg, J. | One kilowatt per capita | 1990 | Energy Resources; Sustainability | Journal | Perspective; 46 (1); | English | Hardcopy:Partial | A review of the energy situation and requirements of developing countries | .. energy policy, like other policies, is biased toward the desires of the elites.; .. the vast majority of the rural population in developing countries still use mainly biomass sources - firewood, agricultural wastes and dung.; The results of one systematic computation of direct energy needs suggest that they can be met by an average of 0.3-0.8 kilowatt per capita per day. .. in the mid 1970s the per capita kilowatt usage of industrialised countries ranged from slightly under one kilowatt to slightly over two kilowatts. It is more difficult to quantify the amount of energy consumed indirectly in the form of basic goods and services. One approach is to compare national per capita energy consumption with measures of quality of life. Such comparisons have indicated that above the range of 1.1-1.3 kilowatts per capita improvements in the quality of life are only marginal.This suggests that with current energy technologies an energy consumption rate of 1.1-1.3 kilowatts per capita can satisfy basic human needs .. |
| 555 | Goodland, R. | Environmental sustainability in agriculture: diet matters | 1997 | Stockless Farming; Sustainability | Journal | Ecol. Econ.; 23; 189-200 | English | Hardcopy:Full; PDF:Full | Agricultural sustainability requires us to eat lower on the food chain, eating less or not meat and more grains. Taxing food according to the efficiency and the pollution involved in its production is advocated to induce people to change their diet. | Cattle raising is one of the most damaging components of agriculture. Livestock now eat about half of global grain production.; .. livestock now outnumber humans 3:1.; Most nations were .. self-sufficient in food until the early 1960s; now only a few are. .. Now only Canada and the U.S. are major grain exporters.; The production of one pound of beef consumes over 2700 gallons of water, whereas one pound of grain production consumes less than 200 gallons and vegetables about half that.; .. methane from cattle contributes 2.5% of global greenhouse gas production.; One acre of cereals can produce twice to ten times .. [and] one acre of legumes .. ten to twenty times more protein than an acre in beef production. |
| 109 | Goodland, R. & Pimentel, D. | Environmental sustainability and integrity in the agriculture sector | 2000 | Sustainability | Book | Pimentel, D., Westra, L. & Noss, R.F. (eds.); Ecological Integrity: Integrating Environment, Conservation & Health; | English | Hardcopy:Partial; Wordperfect:Full | Review of measures necessary to make agriculture sustainable | .. the rate of water extraction needs to be balanced with either replenishment rate or the rate of development of a substitute.Most (87 percent) of the world's fresh water is used by the agriculture sector. .. sustainable agriculture will often yield less per area than today's high-input and depleting agriculture in the short term, so demand management (involving such activities as controlling population and stabilising living standards) are essential to achieving sustainability.; .. in order to achieve long-term sustainability and integrity in agriculture, the following three circumstances are envisaged: (1) most people of the world .. would stay at the low end of the chain, but would diversify their diet; (2) affluent people now eating at the top of the food chain would pay full costs or elect to consume more efficiently lower down the food chain; and (3) people starting to move up the food chain (e.g. in China and India): would be encouraged to stop where they are ... |
| 613 | Goodlass, G., Halberg, N. & Verschuur, G. | Input-output accounting systems in the European community: an appraisal of their usefulness in raising awareness of environmental problems | 2003 | Sustainability | Journal | Eur. J. Agron.; 20 (1-2); 17-24 | English | Hardcopy:Partial | Survey of over fifty farm-level input output accounting systems from various European countries | The subjects covered by the IOAs included nutrients, pesticides, energy, soil/habitat, conservation, wastes (e.g. packaging and tyres) and other items such as veterinary products. Nearly half the IOAs covered more than one subject and nutrient budgets were the most commonly included (91% of the IOAs studied).; .. economic issues need to be considered, because, if the costs to the farmer outweigh the benefits, uptake will not be sustained.; .. more studies are needed to ensure that farmers in reality change their behaviour .. |
| 951 | Goossens, A., Visscher, A.D., Boeckx, P. & Cleemput, O. van | Two-year field study on the emission of N2O from coarse and middle-textured Belgian soils with different land use | 2001 | Greenhouse Gases | Journal | Nutr. Cycl. Agroecosyst.; 60 (1-3); 23-34 | English | Hardcopy:Partial | N2O emissions from forest, grass and arable land with various soil textures was measured over 2 years. | @; .. land use rather than soil properties influenced the N2O emission.; .. the N2O-N loss per unit of fertiliser N applied is larger for intensively managed and heavily fertilised (up to 500 kg N ha-1) grasslands than for arable lands and is substantiall |
| 644 | Goss, M.J., Howse, K.R., Christian, D.G., Catt, J.A. & Pepper, T.J. | Nitrate leaching: modifying the loss from mineralised organic matter | 1998 | Cover Crops; Soil N Dynamics; Tillage | Journal | Eur. J. Soil Sci.; 49; 649-659 | English | Hardcopy:Partial | 4-year expt. to compare the effect of different winter treatments on nitrate leaching from the soil | .. reducing tillage depth, incorporating harvest residues, reducing fertiliser N by growing unfertilised grass or by spring-sown rather than autumn-sown crops .. were compared with a control treatment in which autumn crops were sown after burning harvest residues, mouldboard ploughing and seedbed preparation. Winter cover cropping [with white mustard and forage rape] was also compared with winter fallowing.; Only unfertilised grass resulted in a consistent and significant reduction in nitrate leaching during autumn and winter. .. Sowing a cover crop and winter fallowing both resulted in increased leaching of nitrate compared with the control. |
| 1652 | Goswami, D.Y. (ed.) | Alternative Energy in Agriculture | 1986 | Energy in Agriculture; Tillage | Book | Goswami, D.Y.; Alternative Energy in Agriculture; | English | Hardcopy:Partial | Fuel requirements for various farming operations. Also, possible use of solar energy in agriculture. Also, biomass resources of U.S.A. (as alcohol). Figures given show a 33.4 l/ha saving in diesel for zero tillage as compared with conventional cultivation, which requires a total of about 54 l/ha of diesel for cereal growing. | |
| 1111 | Goulden, M.L., Munger, J.W., Fan, S.M., Daube, B.C. & Wofsy, S.C. | Exchange of carbon dioxide by a deciduous forest: response to interannual climate variability | 1996 | Greenhouse Gases | Journal | Science; 271; 1576-1578 | English | Hardcopy:Full | Measurements of net CO2 by New England forest in relation to weather | .. the carbon balance .. of the earth's terrestrial biosphere varies by 1 gigaton of C per year or more from year to year.; The forest gained 30 to 60 kg C ha-1 day-1 in the growing season and lost 10 to 20 kg C ha-1 day-1 in the dormant periods. Annual net CO2 uptake ranged from 1.4 to 2.8 metric tons C ha-1 .. |
| 935 | Goulding, K.W.T., Bailey, N.J., Bradbury, N.J., Hargreaves, P., Howe, M., Murphy, D.V., Poulton, P.R. & Willison, T.W. | Nitrogen deposition and its contribution to nitrogen cycling and associated soil processes | 1998 | Greenhouse Gases; Soil N Dynamics | Journal | New Phytol.; 139 (1); 49-58 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the effect of atmospheric N deposition on forest, grassland and arable soils | N depos'n to winter cereals at Rothamsted is c. 45 kg N ha-1 yr-1; deposition to woodland is likely to be 100 kg N ha-1 yr-1 or more. .. effects on arable land are minimal, but .. the unfertilised plot .. receives enough N to maintain a yield `of 1-2 t wheat ha-1 yr-1.. Such an amount of free N would greatly benefit organic .. farming systems, but will significantly change semi-natural habitats. |
| 136 | Goulding, K.W.T., Murphy, D.V., MacDonald, A., Stockdale, E.A., Gaunt, J.L., Blake, L., Ayaga, G. & Brookes, P.C. | The role of soil organic matter and manures in sustainable nutrient cycling | 2001 | Soil Organic Carbon; Stockless Farming; Soil N Dynamics | Book | Rees, R.M., Ball, B.C., Campbell, C.D. & Watson, C.A. (eds.); Sustainable Management of Soil Organic Matter; | English | Hardcopy:Partial; Wordperfect:Full | Review of recent research into the quantification of gross N transformations, into the size and significance of the soil soluble N pool and into the comparative effectivness of FYM and chemical fertilisers in the supply of nutrients | Generally, for immobilisation to dominate over nitrification and for N to be conserved, sufficient C is needed to drive the heterotrophic organisms that immobilise ammonium. Thus C & N availability determine the rate & balance of MIT and the supply of nitrate available for plant uptake or loss to the environment. Exudates from the .. root mass .. could be the source of the C needed to cause immobilisation to dominate.; .. as much soluble org. N as mineral N can exist in soil under agricultural cropping systems.; Under continuous arable cultivaH tion the size of the soluble org. N pool is relatively constant at 15-20 kg N/ha ... Under ploughed-out grass the .. pool size is larger at 20-25 kg N/ha. |
| 873 | Goulding, K.W.T., Stockdale, E.A., Fortune, S. & Watson, C.A. | Nutrient cycling on organic farms | 2000 | Organic Farming | Journal | J. R. Agric. Soc. Engl.; 161; 65-74 | English | Hardcopy:Partial | Review of the possible sustainability of organic farming, given its dependence on feedstuffs and bedding for inputs of P and K and on the very variable fixation by legumes or imports of manure or compost for N. | Stockless systems are possible. .. Most common is a 2-year grass-red clover ley, which can accumulate 250-370 kg N/ha and is cut and mulched .. The transition from ley to arable cropping in an organic rotation is generally associated with the highest loss, with up to 180 kg N/ha leached in the winter after ploughing.; Losses of N from organic systems can be as large as those from conventional systems .. they are even more difficult to limit than those from fertilisers applied to conventional farms. There is some evidence of P deficiency in soils under organic production. |
| 977 | Goñi, M.A. & Eglinton, T.I. | Stable carbon isotopic analyses of lignin-derived CuO oxidation products by isotope ratio monitoring-gas chromatography-mass spectrometry (irm-GC-MS) | 1996 | Lignin and CBW; Soil Organic Carbon | Journal | Org. Geochem.; 24 (6/7); 601-615 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to test the efficacy of stable carbon isotope analysis as a means of differentiating between cupric oxide oxidation products of lignin | Most lignin-derived CuO reaction products retain the isotopic signature of their biopolymeric precursor and therefore can be used to characterise the isotopic composition of parent lignins in natural samples. Vascular plant tissues yield lignin reaction products with distinctive isotopic signatures which reflect their major biosynthetic pathways and differentiate between C3 and C4 sources.; .. it is possible to characterise directly the isotopic compos'n of .. lignins by combined application of alkaline CuO oxidation and irm-GC-MS without the need for prior demineralisation. |
| 1722 | Grandy, A.S. & Robertson, G.P. | Aggregation and Organic Matter Protection Following Tillage of a Previously Uncultivated Soil | 2006 | Uncategorised | Journal | Soil Sci. Soc. Am. J.; 70; 1398-1406 | English | PDF:Full | ||
| 820 | Grandy, A.S., Loecke, T.D., Parr, S. & Robertson, G.P. | Long-term trends in nitrous oxide emissions, soil nitrogen and crop yields of till and no-till cropping systems | 2006 | Greenhouse Gases; Soil N Dynamics; Tillage | Journal | J. Environ. Qual.; 35; 1487-1495 | English | Hardcopy:Partial; PDF:Full | 12-yr field expt. to study the effect of tillage on N2O emissions, N availability and crop yields | .. no-till increased soil C in the top 5 cm .. and increased aggregate MWD ..; Average N2O emissions were similar in till & no-till.; Mean annual NO3- concentrations in no-till were significantly less than in conventional till ..; .. lower soil NO3- concentrations did not result in lower yields. |
| 35 | Granstedt, A.G. | The mobilisation and immobilisation of soil nitrogen after green-manure crops at three locations in Sweden | 1995 | Soil N Dynamics | Book | Cook, H.F. & Lee, H.C.; Soil Management in Sustainable Agriculture; 265-275 | English | Hardcopy:Full | Field expt. to investigate the possibility of predicting the quantity of soil inorganic nitrogen after the ploughing in of a green-manure crop | ... it is possible to predict the crop value of green manure, in the form of the quantity of mineralised nitrogen, if the amount of ploughed-under nitrogen and the carbon/nitrogen ratio are known for a given humification coefficient. The best agreement between measured and simulated values was obtained when a humification coefficient of 35% was assumed, meaning that 65% of the crop carbon (was released as CO2 within about a year of being ploughed under ... At an average N content of 2.4% and a C/N ratio of 19, 34% of the ploughed-under N was released ... while the rest of the N was bound in the humus... |
| 124 | Granstedt, A.G. & Kjellenberg, L. | Quality investigations with the K-trial, Jarna and other Scandinavian fertilisation experiments | 1996 | Biodynamic Farming; Miscellaneous; Organic Farming | Book | Raupp, J. (ed.); Quality of plant products grown with manure fertilisation, Proc. 4th mtg (concerted action AIR3-CT94-1940); | English | Hardcopy:Partial; Wordperfect:Full | Review of yield and quality of produce from conventional and biodynamic farming systems in some long-term field expts | Compared with the conv'l treatments the content of crude protein in the organic treatments was lower but the relative pure protein and the content of essential amino acids were higher in potatoes and wheat.; The average tuber yield .. was the same in the organic & conv'l treatments.; The average [wheat] yield levels in [biodynamic] and [conv'l treatments] were nearly the same. For [the organic treatment], in which there was no application of biodynamic field prep'ns, the yield level was significantly lower. |
| 1112 | Grant, L. | When will the oil run out? | 2005 | Energy Resources | Journal | Science; 309; 52-54 | English | Hardcopy:Partial | Reply to a previous article alleging that there were still 3x109 barrels of recoverable oil resources in the world | the remaining oil totals 2311 billion barrels, a figure closer to other estimates.; .. although the experts may quibble over their differences, they are in broad agreement: all the estimates I have seen agree within a factor of about two as to how much oil remains.; With a projected annual growth worldwide of 1.9% from 2001 to 2025, the 32 years' supply [of oil] would decline to about 26 years. |
| 978 | Grasset, L. & Amblès, A. | Structure of humin and humic acid from an acid soil as revealed by phase transfer catalysed hydrolysis | 1998 | Soil Organic Carbon | Journal | Org. Geochem.; 29 (4); 881-891 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the composition of humus (humin and humic acid) | .. the OM of the initially insoluble humin .. can be almost completely solubilised (87%) when submitted to step-wise hydrolysis under phase-catalysis transfer conditions.; .. significant structural differences do exist between humin & humic acid.; .. fatty acid and alkanol moieties indicates a bacterial input. .. A higher plant input for some lipids is indicated by the presence of ligninderived aromatic acids. Lipids such as hydrocarbons can be present as trapped molecules in the macromolecular network of humin and humic acid. These hydrocarbons are predominantly of bacterial origin. |
| 645 | Greenfield, L.G. | The origin and nature of organic nitrogen in soil as assessed by acidic and alkaline hydrolysis | 2001 | Soil N Dynamics | Journal | Eur. J. Soil Sci.; 52 (4); 575-583 | English | Hardcopy:Full; PDF:Full | Lab. expt. to study the nature of org. N cpds in soil using acid & alkaline hydrolysis | .. the identity of about 35% of the org. N in the soil & the origin of approx. 50% of hydrolysable ammonium is not known or at least is debatable.; Alkaliinsoluble residues from a wide variety of soils contained largely fixed ammonium or chitin or both. Acid hydrolysis of alkali-insoluble residues from soils, microbes, insects & well-rotted plant litter confirmed the presence of hexosamineN.; .. much of this N is in the form of polymeric hexosamines derived largely from fungi and insects. Chitin .. [is] widely distributed in the soil ecosystem, particularly in microbes & insects, but not in plants. Low MW hexosamines, e.g. glucosamine, galactosamine & muramic acid, occur in bacteria & plants, but these will be largely destroyed during alkali hydrolysis, leaving chitin & chitosan residues which are largely insoluble following alkali hydrolysis. |
| 320 | Greenhalgh, J.F.D. | The dilemma of animal feeds and nutrition | 1976 | Stockless Farming | Journal | Anim. Feed Sci. Technol.; 1 (1); 1-7 | English | Hardcopy:Full | Animals are fed on cereals that could be consumed by humans. It is immoral that people starve in poor countries, while cereals that could save them are used to feed livestock in richer countries. The counter argument is an economic one - that the people in the poor countries cannot afford to buy that grain, while the livestock farmer in the richer countries can. | In Britain today the feed requirements of the nation's domestic animals, when expressed in metabolisable energy, are three times those of the country's human population. .. [But] they provide only one third of the energy intake of their consumers.; Most domestic animals are kept to provide food for man, which they do with a woefully poor energetic efficiency.; The food deficit in the developing countries is still small in relation to the food `surplus' that is used for animal feed in the develop[ed countries.; .. the resources of land, labour and capital needed to grow forages [animal feed] could often be used to produce plant foods for direct human consumption. |
| 1482 | Greenland, D.J. | Soil conditions and plant growth | 1997 | Soil (General) | Journal | Soil Use Manag.; 13; 169-177 | English | Hardcopy:Full | Review of existing knowledge of soil conditions and how they influence plant growth (inaugural Russell memorial lecture) | .. to yield gains of wheat in Mexico from 1968 to 1990 .. genetic improvement contributed 28% .., N supply 48% & changes in the resource base & pest & disease incidence the remaining 24%.; .. as the nat'l average wheat yield .. approaches 9 t/ha, the return from the use of high levels of inorg.fertilisers .. will only be fully realised if higher levels of OM can be .. maintained.; The All-India long-term trials.. showed a consistent advantage to the integrated use of inorg. fertilisers & manure ..; on the global extent of degradation .. more than 40% of agric. soils had been degraded ..; If all resources are harnessed & adequate measures are taken to minimise soil degradation, sufficient food can be produced to sustain a population several times more than the present population. |
| 1426 | Gregorich, E.G., Beare, M.H., McKim, U.F. & Skjemstad, J.O. | Chemical and biological characteristics of physically uncomplexed organic matter | 2006 | Soil Organic Carbon | Journal | Soil Sci. Soc. Am. J.; 70; 975-985 | English | Hardcopy:Full; PDF:Full | Review of current knowledge of so-called physically uncomplexed SOM (the SOM fractions that are not bound to mineral particles, including LF & POM) | Physically uncomplexed OM .., compared with the whole soil or heavy fraction, has a wide C/N ratio and high O-alkyl (i.e. carbohydrate) and low carbonyl (i.e. protein) C contents. The response of [it] to changes in land use and management practices is greater than that of other labile OM fractions or the whole soil C and N. .. it is not an immediate source of nutrients. .. the quantity and the biol. & chem. props of phys. uncomplexed OM are affected by the amount, compos'n & accessibility of plant residues entering the soil; env'mtal conditions that may enhance or constrain decomposition; and the fractionation technique used. |
| 516 | Gregorich, E.G., Carter, M.R., Angers, D.A., Monreal, C.M. & Ellert, B.H. | Towards a minimum data set to assess soil organic matter quality in agricultural soils | 1994 | Soil Organic Carbon | Journal | Can. J. Soil Sci.; 74 (4); 367-385 | English | Hardcopy:Partial | Review of the various attributes of soil quality | Soil quality is a composite measure of both a soil's ability to function and how well it functions relative to a specific use.; .. non-humic substance that contribute to the organic C & N contents in soil consist of low-molecular-weight aliphatic and aromatic acids, carbohydrates, amino-acids and their polymeric derivatives such as polypeptides, proteins, polysaccharides and waxes. These compounds have a relatively rapid turnover in soil and are used readily as substrates by soil microorganisms. Humic substances .. consist of complex polymeric organic compounds with high molecular weight and are intimately associated with inorganic constituents [which] make them more resistant to decomposition than the non-humic materials. |
| 517 | Gregorich, E.G., Drury, C.F. & Baldock, J.A. | Changes in soil carbon under long-term maize in monoculture and legume-based rotation | 2001 | Green Manure; Soil Organic Carbon | Journal | Can. J. Soil Sci.; 81; 21-31 | English | Hardcopy:Full | Legume-based cropping systems could help to increase crop productivity and SOM levels, thereby enhancing soil quality, as well as having the additional benefit of sequestering atmospheric C. Organic C abundance was measured in soils under forest, under fertilised and unfertilised continuous grass and under fertilised and unfertilised maize, both in monoculture and in legume-based rotations. | .. the quantity of C inputs was not the primary factor affecting soil C storage. .. residue quality is an important factor in increasing the retention of soil C in agro-eco-systems. .. the quantity of soil C was smaller in the maize monoculture systems than in the rotation systems, even though C inputs were about the same or higher in the monoculture systems. ..; .. soils under legume-based rotation tend to be more `preservative' of residue C inputs .. than soils under monoculture.; .. substantial amounts of C can be mineralised and lost from below the plough layer after the conversion of forest to arable agriculture. |
| 518 | Gregorich, E.G., Ellert, B.H. & Monreal, C.M. | Turnover of soil organic matter and storage of corn residue carbon estimated from natural 13C abundance | 1995 | Mineralisation; Soil Organic Carbon | Journal | Can. J. Soil Sci.; 75 (2); 161-167 | English | Hardcopy:Partial | Expt. to compare the quantity and initial source of OM in a forest soil and a soil under continuous maize for 25 years | The total mass of organic C in the cultivated oils was 19% lower than in the forest soil .. after 25 yr of continuous corn.; [and]; more than 75% of the residue C added to the soil was lost by mineralisation and returned to the atmosphere as CO2. Between 25 and 35% of the organic C in the plough layer was derived from corn residues. .. The turnover was fastest in the LF [which] appeared mainly to comprise recently added residues, about 70% [of which] was derived from corn. |
| 1427 | Gregorich, E.G., Ellert, B.H., Drury, C.F. & Liang, B.C. | Fertilisation effects on soil organic matter turnover and corn residue C storage | 1996 | Soil Organic Carbon | Journal | Soil Sci. Soc. Am. J.; 60; 472-476 | English | Hardcopy:Partial | A comparison of SOM residue and turnover in fertilised and unfertilised soils. Soils under continuous maize cropping and fertilised with nitrogenous chemical fertilisers showed a greater accumulation of organic C than unfertilised soils. @13C measurements showed that the amount of C3-derived C is about the same in both fertilised and unfertilised soils. The difference is accounted for by the greater amount of C4-derived (maize-derived) C in the fertilised soils. | .. adequate fertilisation increases crop yields, in turn leading to greater [crop-derived] C storage .. fertilisation does not significantly alter the rate of turnover of native [C3-derived] SOM.; Larson et al. (1972) found that changes in SOC were linearly related to the amount of residue applied to soil under continuous corn. Rasmussen et al. (1980) .. noted that the changes were independent of the type of residue applied. |
| 1542 | Gregorich, E.G., Greer, K.J., Anderson, D.W. & Liang, B.C. | Carbon distribution and losses: erosion and deposition effects | 1998 | Greenhouse Gases; Soil Organic Carbon; Tillage | Journal | Soil Tillage Res.; 47 (3/4); 291-302 | English | Hardcopy:Full; PDF:Full | Review of research into the effects of erosion and deposition on the storage of C in soils | .. the rate of soil loss on shoulder slope positions after primary and @secondary tillage was greater than 54 Mg ha-1 yr-1 and concluded that this tillage erosion accounted for at least 70% of the soil loss.; .. net mineralisation is the dominant process in the decline of organic C when native grassland soils are first cultivated, and that erosion becomes a major factor in later years. |
| 1543 | Gregorich, E.G., Rochette, P., Bygaart, A.J. van den & Angers, D.A. | Greenhouse gas contributions of agricultural soils and potential mitigation practices in Eastern Canada | 2005 | Greenhouse Gases; Green Manure; Tillage | Journal | Soil Tillage Res.; 83 (1); 53-72 | English | Hardcopy:Partial; Wordperfect:Full | Review of research into the production and mitigation of greenhouse gases in agriculture in eastern Canada | @; In cool temperate regions N2O emission comprises the majority of greenhouse gas emission associated with crop production. Manure is an important source of N2O emission.. Most of the CH4 produced in the agriculture sector is associated with animal produ |
| 1226 | Gregorich, E.G., Voroney, R.P. & Kachanowski, R.G. | Turnover of carbon through the microbial biomass in soils with different textures | 1991 | Soil Microorganisms | Journal | Soil Biol. Biochem.; 23 (8); 799-805 | English | Hardcopy:Full | Lab. expt. to study the effect of labelled glucose on ten soils with different clay contents | Total biomass C (labelled + unlabelled C) contents reached maximal amounts after 1.25 days .. Biomass 14C was maintained at higher amounts in soils with more clay .. until 45 days. The [proportion of C derived from labelled glucose and incorporated in the biomass ranged from 59% to 73% after 1.25 days and from 16% to 20% after 90 days. The labelled biomass was .. correlated with the amount of clay at all sampling dates .. |
| 1723 | Gregory, P.J. | Roots, rhizosphere and soil: the route to a better understanding of soil science? | 2006 | Uncategorised | Journal | Eur. J. Soil Sci.; 57; 2-12 | English | PDF:Full | ||
| 222 | Gregory, P.J., Ingram, J.S.I., Andersson, R., Betts, R.A., Brovkin, V., Chase, T.N., Grace, P.R., Gray, A.J., Hamilton, N., Hardy, T.B., Howdena, S.M., Jenkins, A., Meybeck, M., Olsson, M., Ortiz-Monasterio, I., Palm, C.A., Payne, T., Rummukainena M., Schulze, R.E., Thiema, M., Valentin C. & Wilkinson, M.J. | Environmental consequences of alternative practices for intensifying crop production | 2002 | Agricultural Ecology; Miscellaneous | Journal | Agric. Ecosyst. Environ.; 88; 1-12 | English | Hardcopy:Partial; PDF:Full | Review of possible apporaches to increase world food production | The use of low amounts of external inputs is generally regarded as being the most environmentally benign, although this advantage over systems with higher inputs may disappear if the consequences are expressed per unit of product rather than per unit area. The adverse effects of production systems with high external inputs, especially losses of nutrients from fertilisers and manures to water courses and contributions of gases to climate forcing, have been quantified. Future intensification, including the use of improved germ-plasm via genetic modification, will seek to increase the efficiency of use of added inputs while minimising adverse effects on the environment. However, reducing the loss of nutrients from fertilisers and manures and increasing the efficiency of water utilisation in crop production remain considerable challenges. |
| 17 | Gressel, N. & McColl, J.G. | Phosphorus mineralisation and organic matter decomposition: a critical review | 1997 | Phosphorus Cycling | Book | Cadisch, G. & Giller, K.E. (eds.); Driven by Nature: Plant Litter Quality and Decomposition. C.A.B. International; | English | Hardcopy:Partial; Wordperfect:Full | Review of soil P research up to the present. Scientific opinion differs on whether or not phosphatase activity is the rate-limiting step for organic P mineralisation. | The global P cycle consists of weathering processes, including mineral dissolution, erosion and leaching, which transfer P from the terrestrial environment to oceanic deposits, and of volcanism and uplifting of marine sediments which replenish terrestrial P and complete the cycle.; Concentrations (of total P are low in soils (usually 0.2-5.0 g kg-1) and soil solutions (<1 mg l-1) ..; In agricultural soils most Po is in forms that are .. poor nutrient sources on a time-scale appropriate for agricultural production .. However, forests and other non-agricultural ecosystems rely more heavily on H mineralisation of Po, which typically comprises 30-80% of total P in litter and soil.; On a biological time-scale .. P mineralisation is associated with decomposition of litter and soil OM, although availability of P on a pedogenic time-scale is ultimately controlled by the release of P from primary minerals and subsequent leaching. |
| 269 | Grierson, P.F. & Adams, M.A. | Nutrient cycling and growth in forest ecosystems of south western Australia: relevance to agricultural landscapes | 1999 | Miscellaneous; Sustainability | Journal | Agrofor. Syst.; 45 (1/3); 215-244 | English | Hardcopy:Partial; PDF:Full | Review of the qualities desirable in an agricultural system designed to mimic nature | .. application of such a mimic concept to systems of low natural productivity is limited when agricultural systems require continued high productivity. Nonetheless, the mimic concept may help in developing sustainable management of agriculture on marginal lands and contribute to the nutritional resilience of agroecosystems. Relevant characteristics for mimic agroecosystems .. include: high species diversity, diversity of rooting attributes, utilisation of different forms of nutrients (especially of N and P) in space and time, and the promotion of practices which increase soil organic matter content.; Improving SOM content is crucial .. to the maintenance of soil fertility .. The inclusion of shade trees, mixed cropping of species that differ in phenology (both above- and belowground), controlling weeds and pests through crop rotation, dense spacing, mulching and application of manure rather than through cultivation, are all likely to result in an increase in soil organic matter. |
| 1227 | Grierson, P.F., Comerford, N.B. & Jokela, E.J. | Phosphorus mineralisation kinetics and response of microbial phosphorus to dying and rewetting in a Florida spodosol | 1998 | Phosphorus Cycling | Journal | Soil Biol. Biochem.; 30 (10/11); 1323-1331 | English | Hardcopy:Partial; PDF:Full | Net mineralisation of P in undried soils was best described by zero-order kinetics and in dried and re-wetted soils by a 2-pool model with one pool zeroorder and the other first-order. Net mineralisation in re-wetted soils went in three stages: (1) an initial flush due to turnover of the microbial biomass from the drying period and mineralisation of organic substrates; (2) a lag of a few days with no net release of P; and (3) a period of zero-order kinetics, where the microbial biomass had recovered sufficiently to mineralise P from SOM. | |
| 1653 | Grigg, D.B. | The Agricultural Systems of the World: An Evolutionary Approach | 1974 | Agricultural Ecology | Book | Grigg, D.B.; The Agricultural Systems of the World: An Evolutionary Approach; | English | Hardcopy:Partial | Agricultural systems are reviewed geographically and historically, including, in the pp. photocopied, the characteristics of Mediterranean farming such as transhumance and the development of agriculture, especially mixed farming, in the Middle Ages. | In traditional Mediterranean agriculture every village, if not every farm, would grow cereals, keep sheep and goats and have grapes for wine and olives for cooking oil and lighting.; Both fruits and vegetables have been an important part of Mediterranean farming since at least Roman times ..; .. in northern Europe in Roman times .. oats, barley, wheat and rye were all grown, as was spelt, which remained a major crop until the late Middle Ages .. but vegetables and fruits .. were of little significance. .. There was still much shifting agriculture .. The plough [was] made of wood. .. Most farmers kept livestock as well as growing cereals; pigs probably provided most of the meat .. cropping was unimportant compared with pastoralism.; The date of the introduction of the heavy [steel] plough is still unknown; it seems to have spread slowly .. after the sixth century A.D. Later horses began to be used instead of oxen, .. but horses did not immediately replace oxen; they cost more to feed and could not be sold for meat.; Thus by 1300 .. the main aim of the farmer was to raise cereals .. other crops were rare, although some pulses were grown. |
| 36 | Grimal, J.Y., Frossard, E. & Morel, J.L. | The acquisition of phosphorus sorbed on a goethite by maize | 1995 | Phosphorus Cycling | Book | Cook, H.F. & Lee, H.C.; Soil Management in Sustainable Agriculture; 235-239 | English | Hardcopy:Full | Lab. expt. to determine to what extent maize roots could mobilise phosphorus absorbed on goethite in the absence of microorganisms | After ten days of growth in the presence of phosphated goethite, ... 23.5% of the sorbed P was removed from the goethite, whereas less than 1% was extractable by an anionic resin. |
| 775 | Groenestein, C.M. & Faassen, H.G. van | Volatilisation of ammonia, N2O and nitric oxide in deep-litter systems for fattening pigs | 1996 | Greenhouse Gases | Journal | J. Agr. Eng. Res.; 65 (4); 269-274 | English | Hardcopy:Partial | Expt. to compare the gas emissions from pigs kept on slatted floors and on deep litter | @; The N emitted as NH3, NO and N2O measured with System 1 was 0.24, 0.04 and 0.3 g N/h per pig respectively. For System 2 emissions were 0.12, 0.01 and 0.2 g N/h per pig respectively.; .. deep-litter systems for fattening pigs may reduce NH3- emission co |
| 1724 | Gryze, S. de, Jassogne, L., Six, J. & Merckz, R. | Water repellence and soil aggregate dynamics in a loamy grassland soil as affected by texture | 2006 | Uncategorised | Journal | Eur. J. Soil Sci.; 57; 235-246 | English | PDF:Full | ||
| 1725 | Gryze, S. de, Six, J. & Merckx, R. | Quantifying water-stable soil aggregate turnover and its implication for soil organic matter dynamics in a model study | 2006 | Uncategorised | Journal | Eur. J. Soil Sci.; 57; 693-707 | English | PDF:Full | ||
| 1228 | Gryze, S. de, Six, J., Brits, C. & Merckx, R. | A quantification of short-term macroaggregate dynamics: influences of wheat residue input and texture | 2005 | Soil Organic Carbon; Soil (General) | Journal | Soil Biol. Biochem.; 37 (1); 55-66 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the effect of wheat residue decomposition on the macroaggregate dynamics of three fertilised grassland soils of differing textures | Aggregate formation increased linearly with increasing amounts of residue ..; While amounts of water-stable macroaggregates in the sandy loam & the silt loam soil corresponded well with fungal lengths, this was not the case for the silty clay loam soil. This suggests that fungi are less important in aggregate formation in more clayey soils.; .. a macroaggregate turnover time of 40-60 days. |
| 1230 | Guggenberger, G. & Zech, W. | Composition and dynamics of dissolved carbohydrates and lignin degradation products in two coniferous forests, N.E. Bavaria, Germany | 1994 | Lignin and CBW; Soil Organic Carbon | Journal | Soil Biol. Biochem.; 26 (1); 19-27 | English | Hardcopy:Partial | Expt. to study the flux of carbohydrates and lignin-derived substances through the soil. The input was much greater than the output and this was more due to adsorption of the substances on the soil matrix than to their biodegradation. | |
| 646 | Guggenberger, G., Christensen, B.T. & Zech, W. | Land-use effects on the composition of organic matter in particle-size separates of soil: I. Lignin and carbohydrate signature | 1994 | Lignin and CBW; Soil Organic Carbon | Journal | Eur. J. Soil Sci.; 45 (4); 449-458 | English | Hardcopy:Partial | Expts. to compare the quality (including lignin and carbohydrates) and quantity of the OM in soils under forest, arable rotation and grassland (converted from arable rotation in 1956). | Whole soil from spruce forest, deciduous forest, permanent grassland and arable rotation contained 84, 59, 73 and 25 g C per kg. soil respectively. For all sites the C content declined .. in the order: clay (< 2 m), silt (2-20 m), sand (20-2000 m).; [This] is indicative of an increasing degree of humification.; SOM associated with silt has the slowest turnover. |
| 1229 | Guggenberger, G., Elliott, E.T., Frey, S.D., Six, J. & Paustian, K. | Microbial contributions to the aggregation of a cultivated grassland soil amended with starch | 1999 | Soil Microorganisms; Soil (General) | Journal | Soil Biol. Biochem.; 31 (3); 407-419 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the effect of microorganisms on the formation of macroaggregates from microaggregates in soil amended with starch | .. we observed no formation of macroaggregates in the control samples (incubated without starch amendment) & the undecomposed starch did not glue microaggregates into macroaggregates either. We suggest that microhabitats enriched in substrate acted as hot-spots for fungal growth .. However, the stabilisation of the macroaggregates throughout the expt may be attributed to other factors that persist after cell death of the microorganisms. In-situ mineralis'n rate constants of [starch-derived] C were much lower for the microaggregates compared with .. macroaggregates, indicating a better stabilis'n of starch-derived C within the microaggregates & .. supporting the macro- [&] microaggregate conceptual model. |
| 1428 | Guggenberger, G., Frey, S.D., Six, J., Paustian, K. & Elliott, E.T. | Bacterial and fungal cell-wall residues in conventional and no-tillage agroecosystems | 1999 | Soil Microorganisms; Tillage | Journal | Soil Sci. Soc. Am. J.; 63 (5); 1188-1198 | English | Hardcopy:Partial; PDF:Full | In soil samples from long-term conventional v. zero tillage trials microbial necromass (mass of dead cells) is estimated by determining the concentration of glucosamine, a product of the hydrolysis of chitin (poly-N-acetyl glucosamine) that is commonly found in the cell walls of fungi, and muramic acid, which is exclusively found in the cell walls of bacteria. Glucosamine is not a suitable indicator, however, for fungal biomass (mass of living cells) - the cell-wall residues have a much longer turn-over time in the soil than the living microorganisms, are physically protected from microbial decomposition inside soil aggregates and may represent a microbially derived intermediate SOM pool that accumulates in NT systems. | Beare (1997) showed that litter placement exerts a profound influence on the composition of decomposer communities. CT systems, where litter is buried, favour a bacterial-dominated community, whereas in surface litter .. of NT systems filamentous fungi are relatively more abundant.; .. hyphae are important in the formation and stabilisation of macroaggregates .. During .. the expt. fungal and bacterial biomass declined rapidly [but] macroaggregates remained stable. This suggests that more recalcitrant compounds like cell-wall residues were involved in the aggregate stabilisation. .. However, a clear cause-and-effect relationship between aggregation and accumulation of cell-wall residues still needs to be [established]. |
| 1231 | Guggenberger, G., Zech, W. & Thomas, R.J. | Lignin and carbohydrate alteration in particle-size separates of an oxisol under tropical pastures following native savanna | 1995 | Lignin and CBW; Soil Organic Carbon | Journal | Soil Biol. Biochem.; 27 (12); 1629-1638 | English | Hardcopy:Partial | Expt. to study the changes in SOM following the establishment of pastures following native grassland | .. [the results] indicated progressive lignin alteration with decreasing particle size.; Clay-bound SOM was rich in microbially-derived sugars ..; Earthworm casts were characterised by a tremendous enrichment of C, intact lignin and plant-derived sugars .. compared with the surrounding soil. |
| 647 | Guggenberger, G., Zech, W., Haumaier, L. & Christensen, B.T. | Land-use effects on the composition of organic matter in particle-size separates of soils: II. CPMAS and solution 13c NMR analysis | 1995 | Soil Organic Carbon; Tillage | Journal | Eur. J. Soil Sci.; 46 (1); 147-158 | English | Hardcopy:Partial | Lab. expt. to study the composition of SOM in different fractions of forest, grassland and arable soils | .. sand-sized separates were enriched in plant residues .. whereas clay-sized separates were dominated by products of microbial re-synthesis. Silt was rich in selectively preserved & microbially transformed primary resources.; ..arable rotation decreased SOM .. in all size separates, but the proportion of wholesoil SOM in clay increased .. probably due to loss of stabilisation of POM after disintegration of soil aggregates upon cultivation.; Perm. grassland resulted in a high proportion of lignin and plant-derived carbohydrates in the sand-sized separates .. probably due to a high rate of rhizodeposition and occlusion of plant residues within aggregates. |
| 37 | Guiking, F.C.T. & Stomph, T.J. | The modification of soil processes by mulching in the humid tropics | 1995 | Mulch | Book | Cook, H.F. & Lee, H.C.; Soil Management in Sustainable Agriculture; 383-386 | English | Hardcopy:Full | Review of the effects of mulch on the soil in the humid tropics | Improved crop performance in mulched fields is generally ascribed to one or a combination of the following changes in growth conditions: reduced water loss by evaporation, increased infiltration, reduced temperature fluctuations and improved nutrient status.; The main positive effect of mulch in the humid tropics is likely to be the build-up and maintenance of a flourishing soil (micro)fauna and flora. |
| 1385 | Guimarães, M.F., Nascimento Filho, V.F. & Ritchie, J.C. | Application of Cesium-137 in a study of soil erosion and deposition in southeastern Brazil | 2003 | Soil (General) | Journal | Soil Sci.; 168 (1); 45-53 | English | Hardcopy:Partial | The cesium-137 concentrations in soil samples from a valley in Brasil were measured and used to assess the relative rate of soil loss in that locality. | @; One of the most abundant radionuclides, 137Cs has a relatively long half-life (30.2 years). Once in contact with the soil, 137Cs is quickly adsorbed to fine particles and .. is not easily removed.; The vertical distribution of 137Cs in the soil profile |
| 1232 | Gunapala, N. & Scow, K.M. | Dynamics of soil microbial biomass and activity in conventional and organic farming systems | 1998 | Organic Farming; Soil Microorganisms | Journal | Soil Biol. Biochem.; 30 (6); 805-816 | English | Hardcopy:Partial; PDF:Full | Field expt. to compare the quantity and activity of microorganisms in conventionally and organically farmed soils | After one 4-y rotation cycle, total OM content had increased in the organic system by 8-15% in comparison to the conventional systems and since then OM contents have been consistently and significantly higher in ... organic than conventional systems. More significant was the increase in the amount of C associated with microbial biomass in the organic ... relative to the conventional system, ... |
| 1233 | Gunapala, N., Venette, R.C., Ferris, H. & Scow, K.M. | Effects of soil management history on the rate of organic matter decomposition | 1998 | Organic Farming; Soil Organic Carbon; Soil Microorganisms | Journal | Soil Biol. Biochem.; 30 (14); 1917-1927 | English | Hardcopy:Partial; PDF:Full | Long-term field expt. comparing the rate of organic matter decomposition in organically and conventionally managed soils | .. soils managed under org. farming practices had greater microbial abundance & activity .. during crop growth than those managed under conv'l .. We tested rates of organic matter decompos'n in the two soils and monitored the abundance and activity of soil biota during the decomposition process. Differences in soil biology between soils from org. & conv'l farming systems did not persist when soils were amended with OM & maintained under similar conditions. Microbial communities in soil from the conv'l system were sufficient and active enough to respond to org. inputs. There were minimal differences in the ability of the microbial communities of the two soils to decompose organic residues. |
| 1429 | Guo, F., Yost, R.S., Hue, N.V., Evensen, C.I. & Silva, J.A. | Changes in phosphorus fractions in soils under intensive plant growth | 2000 | Phosphorus Cycling | Journal | Soil Sci. Soc. Am. J.; 64 (5); 1681-1689 | English | Hardcopy:Partial; PDF:Full | Study of the changes in the various P fractions in eight soils during a 14-year cropping with maize and soya beans. NaOH-Pi was a buffer for available P (strip-P xand NaHCO3-Pi) in highly weathered soils, HCl-P and residual P only in slightly weathered soils. | Organic P may be important in P fertility in unfertilised soils or soils with high OM, but it does not appear to affect P availability significantly in high-P mineral soils. |
| 980 | Gupta, N.S., Briggs, D.E.G., Collinson, M., Evershed, R.P., Michels, R. & Pancost, R.D. | Reply to de Leeuw's comment 'On the origin of sedimentary aliphatic macromolecules' | 2007 | Soil Organic Carbon | Journal | Org. Geochem.; 38; 1588-1591 | English | Hardcopy:Full; PDF:Full | Review of the research on aliphatic macromolules in fossilised plants | Examination of the fossil organisms' extant analogues fails to reveal direct biological precursors... research indicates that aliphatic geomacromolecules in fossils derive from the in-situ incorporation and polymerisation of labile aliphatic compounds (including both high and low molecular weight compounds) from the organism. Other workers .. have suggested that the process of oxidative cross-linking accounts for the fossilisation of some algae and Archaea which likewise lack resistant aliphatic biopolymers in the living organism. |
| 979 | Gupta, N.S., Briggs, D.E.G., Collinson, M., Evershed, R.P., Michels, R., Jack, K.S. & Pancost, R.D. | Evidence for the in-situ polymerisation of labile aliphatic organic compounds during the preservation of fossil leaves: implications for organic matter preservation | 2007 | Soil Organic Carbon | Journal | Org. Geochem.; 38; 499-522 | English | Hardcopy:Partial; PDF:Full | Field expt. to compare the aliphatic content of fossil leaves and leaves from analogous modern plants | Chemical degradation of the modern plants failed to reveal the presence of the aliphatic biomacromolecule cutan, thereby precluding selective preservation of this cpd as the source of the aliphatic component of the fossil leaves. ..investigations of the fossils revealed no evidence for cuticle preservation and, while a contribution from cutin cannot be excluded, the aliphatic component of the fossil polymer is possibly derived instead from the in-situ polymerisation of labile cell membrane lipids and free fatty acids. |
| 1234 | Gupta, V.V.S.R. & Germida, J.J. | Distribution of microbial biomass and its activity in different soil aggregate size classes as affected by cultivation | 1988 | Soil Microorganisms | Journal | Soil Biol. Biochem.; 20 (6); 777-786 | English | Hardcopy:Partial | Study of the microbial biomass in different aggregate size classes in native soil and soil cultivated for 69 years | Cultivation decreased microbial biomass content, its activity and enzyme activity .. Microaggregate (<250 m) .. in both native and cultivated soils contained lower organic C, microbial biomass C, fungal biomass .. and respiratory activities as compared to macroaggregates. .. the negative effects of cultivation were more pronounced on macroaggregate .. |
| 120 | Guy, S.O. | Crop rotation and residue durability effects of brassicas and other crops on winter wheat | 1999 | Miscellaneous; Rape and Biodiesel | Book | ; Proceedings of the Tenth International Rapeseed Conference; | English | Hardcopy:Full | 2-year field expt. to determine the effect of previous crops on the yield of winter wheat. The results are generally rather inconclusive, but in on year there is a significant increase in wheat yield following peas and lentils as previous crop. | |
| 1544 | Guérif, J., Richard, G., Dürr, C., Machet, J.M., Recous, S. & Roger-Estrade,J. | A review of tillage effects on crop residue management, seedbed conditions and seedling establishment | 2001 | Tillage | Journal | Soil Tillage Res.; 61; 13-32 | English | Hardcopy:Partial; PDF:Full | Review of tillage effects on crops | .. crop residues left on the soil surface .. limit evaporation, soil sealing and soil crusting .. thus increase infiltration and limit soil erosion .. [but] may affect soil thermal regime and reduce grain yield .. can impede crop establishment and provide a favourable habitat for slugs. |
| 759 | Gómez-Ibáñez, D.A. | Energy, economics and the decline of transhumance | 1977 | Energy in Agriculture | Journal | Geogr. Rev.; 67; 284-298 | English | Hardcopy:Partial | Energy flows are compared in transhumance and in modern systems that have succeeded it in the western United States. The energy efficiency of transhumance is shown to be greater than that of more modern systems | Agriculture in industrialised societies (and 'Green Revolution' agriculture) depends on large inputs of energy in the form of petroleum.; In the U.S. an average of 10 joules is required to put one joule's worth of food on the table.; It is profitable only because we still measure efficiency in terms of dollars rather than energy or work and because fossil fuels are still available. As these sources of energy become scarcer and more expensive, energy-subsidised agricultural systems must evolve toward energy efficiency. A reversal in the trends of the last two centuries might be realised by a shift from fossil fuels to solar energy sources, including an increasing use of human labour and animal traction ..; The quest to improve the energy efficiency of modern agriculture will benefit greatly from investigations of traditional agricultural systems in which there is no energy subsidy. .. In traditional systems each joule of work expended .. obtains more than one joule's worth of food. Any other result leads to starvation. .. |
| 690 | Gómez-Rodríguez, O., Zavaleta-Mejía, E., González-Hernández, V.A., Livera-Muñoz, M. & Cárdenas-Soriano, E. | Allelopathy and microclimatic modification of intercropping with marigold on tomato early blight disease development | 2003 | Allelopathy | Journal | Field Crops Res.; 83 (1); 27-34 | English | Hardcopy:Partial | Expt. to test the effect of marigolds on the disease resistance of tomato plants | .. intercropping [tomato] with marigold induced a significant reduction in tomato early blight caused by A. solani ..; .. marigold helped tomato plants in 3 different ways: .. by the allelopathic effect on A. solani development; .. by reducing maximal RH [relative humidity] to levels lower than 92%, since this pathogen requires high humidity ... [and by] act[ing] as a physical barrier against spore dispersion.; Our results show a clear allelopathic effect of marigold leaves on A. solani development .. this allelopathic effect is due to the ability of marigold leaves to produce and liberate volatile tiophenes. |
| 1037 | Görres, J.H., Savin, M.C., Neher, D.A., Weicht, T.R. & Amador, J.A. | Grazing in a porous environment: 1. The effect of soil pore structure on C and N mineralization | 1999 | Soil Organic Carbon; Soil Microorganisms; Soil N Dynamics | Journal | Plant Soil; 212 (1); 75-83 | English | Hardcopy:Partial; PDF:Full | Review of the effect of grazing on microbial abundance and activity and on C & N mineralisation | Grazing of microorganisms by soil microfauna accelerates nutrient mineralisation, contributing up to 30% to N mineralisation. Microbivorous soil animals contribute directly to nutrient mineralisation by egesting mineral nutrients derived from their forage and indirectly by affecting microbial growth rates and changing the structure of the microbial communities. |
| 1 | Haas, G., Berg, M. & Köpke, U. | Nitrate leaching: comparing conventional, integrated and organic agricultural production systems | 2001 | Organic Farming; Soil N Dynamics | Book | Steenvorden, J., Claessen, F. & Willems, J. (eds.); Agricultural Effects on Ground and Surface Waters; | English | Hardcopy:Partial; Wordperfect:Full | Field expt. to study the extent of nitrate leaching under conventional, integrated and organic farms | Shifting from conventional to an integrated practice only 15% less nitrate leached and lower nitrate concentration was found. By converting to organic farming a reduction in N leaching losses of more than 50% ... Yields of the organic field plots were lower [But] Comparing the dry matter yield of the cash crops sugar beets, potatoes, winter wheat and rye in relation to the amount of leached nitrate on average of both sites, the production efficiency (kg nitrateN ha-1 yr-1 leached related to dm yield ha-1 yr-1) of the organic farming system was clearly higher (relatively 100% conventional compared to 80% integrated and 57% organic). |
| 413 | Haas, G., Geier, U., Schulz, D.G. & Köpke, U. | Vergleich konventioneller und organischer Landbau, Teil I: klimarelevante Kohlendioxid-Emission durch den Verbrauch fossiler Energie | 1995 | Energy in Agriculture; Greenhouse Gases; Organic Farming | Journal | Ber. Landwirtsch.; 73; 401-415 | German | Hardcopy:Full; Wordperfect:Full | Calculation of the energy use and amount of CO2 emission in organic and convenxtional farming. The gross CO2 emissions in organic and conventional farming are @reckoned to be 0.503 and 1.196 tons CO2 per hectare respectively. The corresponding figures for energy use are 6.8 and 18.9 GJ per hectare. So organic farming is significantly better than conventional in these respects. | n/a [title contd.: durch den Verbrauch fossiler Energie] |
| 772 | Haas, G., Wetterich, F. & Geier, U. | LCA methodology: framework in agriculture on the farm level | 2000 | Miscellaneous | Journal | Int. J. Life Cycle Assess.; 5 (6); | English | Hardcopy:Partial; Wordperfect:Full | Methodological study of a survey designed to compare the enviromental impact of 18 farms (6 each under intensive, extensive and organic systems), using LCA | |
| 223 | Haas, G., Wetterich, F. & Köpke, U. | Comparing intensive, extensified and organic grassland farming in southern Germany by process life-cycle assessment | 2001 | Energy in Agriculture; Greenhouse Gases; Organic Farming | Journal | Agric. Ecosyst. Environ.; 83 (1/2); 43-53 | English | Hardcopy:Partial | Field expt. to compare conventional and organic farming in respect of the energy xconsumed, the CO2 emitted and other environmental impacts | Energy consumption of intensive farms was 19.1 GJ/ha ..., of ... organic farms ... 5.9 GJ/ha. Global warming potential was 9.4 ... and 6.3 CO2 equivalents/ha.; Farm-gate balances for N (80.1 ... and 31.1 kg/ha) and P (5.3 ... and -2.3 kg/ha) ... indicate the different impacts on ground and surface water quality. |
| 614 | Habekotté, B. | Identification of strong and weak yield-determining components of winter oilseed rape compared with winter wheat | 1997 | Rape and Biodiesel | Journal | Eur. J. Agron.; 7; 315-321 | English | Hardcopy:Partial | Field expt. to determine the main factors determining the lower yield of rape as compared with wheat. Wheat yield averaged 8.1 t/ha as compared with 4.7 t/ha for rape. The difference was mainly due to the 12% higher cumulative absorption of photosynthetically active radiation, the 35% higher radiation use efficiency and the 35% higher harvest index of wheat, as compared with rape. | |
| 691 | Habekotté, B. | Options for increasing seed yield of winter oilseed rape (Brassica napus): a simulation study | 1997 | Rape and Biodiesel | Journal | Field Crops Res.; 54 (2-3); 109-126 | English | Hardcopy:Partial | Expt. to determine how plant breeding could best improve the yield of winter oilseed rape | .. higher seed yields may be obtained through (in descending order of importance): (a) delayed maturity; (b) improved seed set: (c) smaller petals or apetalous flowers; (d) increased potential growth rate of individual seeds; (e) earlier flowering with retention of the duration of total growth period and (f) erect clustered pods.; The most promising crop type for high seed yield matures late, combines early flowering with a maximum LAI of about 3 for almost maximum light absorption and has erect clustered pods for source improvement. To take full advantage of the source the sink has to be increased through a high rate of seed set, a large sink capacity of individual seeds, apetalous flowers or a combination of these characteristics. |
| 648 | Hadas, A., Doane, T.A., Kramer, A.W., Kessel, C. van & Horwath, W.R. | Modelling the turnover of 15N-labelled fertiliser and cover crop in soil and its recovery by maize | 2002 | Green Manure; Organic Farming; Soil N Dynamics | Journal | Eur. J. Soil Sci.; 53; 541-552 | English | Hardcopy:Partial; PDF:Full | Field expt. in which the recovery of labelled N-fertiliser by maize was measured in soils under three mgmnt systems: conventional, low-input (vetch+chemical fertiliser) & organic (vetch+composted FYM), in order to test the synchronisation between N release and the requirements of the crop. The vetch and FYM were incorporated into the soil 1 week prior to planting the maize. | .. in the ORG system .. the maximal availability of N was reached at about the same time as the fertiliser was applied in the LI and CONV systems. .. may therefore be made to coincide with maximum demand by the crop .. |
| 1235 | Hadas, A., Kautsky, L., Goek, M. & Kara, E.E. | Rates of decomposition of plant residues & available N in soil related to residue composition through simulation of carbon and nitrogen turnover | 2004 | Mineralisation; Soil Organic Carbon; Soil N Dynamics | Journal | Soil Biol. Biochem.; 36 (2); 255-266 | English | Hardcopy:Partial; Wordperfect:Full | Expt. to study the decomposition in the soil of plant residues with various C/N ratios, including wheat straw and tobacco, rape, rice and maize residues. Tobacco, rape and maize decomposed equally rapidly (14-18% of their C in the first week), even though maize had a C/N ratio 2.5-3 times greater than the others. This was probably because of the large proportion of the maize C (30-35%) in soluble form. The decomposability of residue fractions is more important in determining decomposition rates than C/N ratio. | Vigil & Kissel (1991) .. showed that the break-even point between net N immobilisation and mineralisation of residues was at a C/N ratio of 41. This corresponds to an N content of ca. 1%, meaning that 1 g of N is retained in soil per 100 g of decomposing residue, a value commonly accepted as the amount of fertiliser-N needed to compensate for N immobilisation when straw is incorporated in soil.; Large quantities of available C added to the soil, e.g. in the form of residues with large C/N ratios, will stimulate microbial growth and N immobilisation, as well as microbial activity and oxygen consumption that may cause temporary conditions for denitrification. |
| 649 | Hadas, A., Parkin, T.B. & Stahl, P.D. | Reduced CO2 release from decomposing wheat straw under N-limiting conditions: simulation of carbon turnover | 1998 | Soil Organic Carbon | Journal | Eur. J. Soil Sci.; 49; 487-494 | English | Hardcopy:Partial; PDF:Full | Modifying the NCSOIL model to simulate the CO2 release from decomposing straw in conditions of restricted N supply. | .. the turnover of endogenous mineralisable SOM by soil microbial biomass and the turnover of added residues by a zymogenous microbial biomass.; .. when N is deficient microbial use efficiency (the fraction of decomposed C used for microbial growth) decreases ..; When N was not limiting microbial growth, microbial use efficiency was 0.6 and there was no accumulation of polysaccharides. In the C-N treatment [addition of chopped wheat straw] the microbial efficiency was considerably less, but increased with time because available C was continuously depleted by being partly released as CO2 and partly sequestered into a polysaccharide pool that was less decomposable than the residue ..; Long-term persistence of microbial polysaccharides has been demonstrated in a field expt., where significant differences in polysaccharide content of the soil were found 4 months after differential management treatments and even after a longer time ..; The rate of CO2 release from samples with straw and N .. was rapid for the first 50 days, in which 40% of added C was mineralised. .. The rate declined towards 150 days.. The total amount released in 460 days was 58% of added C. |
| 1236 | Hadas, A., Sofer, M., Molina, J.A.E., Barak, P. & Clapp, C.E. | Assimilation of nitrogen by soil microbial population: NH4 versus organic N | 1992 | Mineralisation; Soil Microorganisms; Soil N Dynamics | Journal | Soil Biol. Biochem.; 24 (2); 137-143 | English | Hardcopy:Full | Inconclusive lab. expt. to ascertain the pathway by which organic N enters microorganisms, directly or via the soil inorganic N pool | .. the decay of OM can follow two patterns: (1) microbes incorporate low MW organic N compounds .. This .. assumes that N transfer .. is mostly mediated through organic compounds and that N mineralisation or immobilisation occurs only when there is an excess or deficit of N with respect to biomass needs to maintain their C/N ratio ..; (2) microbial biomass immobilises N only from the inorganic pool, while decay always results in N mineralisation and release of (NH4+ into the inorganic pool (the mineralisation-immobilisation turnover, MIT, hypothesis).; .. a zymogenous population developed on the added organic substrate (alanine) and possibly directly assimilated the organic N for growth. But at the same time the native soil population developed ..,consuming the H available SOM and probably assimilated NH4+, as suggested by the MIT hypothesis. |
| 1237 | Hagedorn, F., Spinnler, D. & Siegwolf, R. | Increased N deposition retards mineralisation of old soil organic matter | 2003 | Mineralisation; Soil Organic Carbon; Soil N Dynamics | Journal | Soil Biol. Biochem.; 35 (12); 1683-1692 | English | Hardcopy:Partial | An investigation of the effects of increased N deposition on new and old pools of SOM in a 4-yr expt. on spruce and beech growing on an acidic loam and a calcareous sand | Elevated N deposition for 4 yr increased significantly the contents of total SOM in 0-10 cm depth of the acidic loam (+9%) .. Down to 25 cm soil depth, C storage in the acidic loam was between 100 and 300 g C m-2 larger under high than under low N additions.; The amounts of new (less than 4-yr-old) SOM in the sand fractions of both soils were greater under high N deposition, showing that C inputs from trees into soils increased. Root biomass in the acidic loam was larger under N additions (+25%). Contents of old (more than 4-yr-old) C in the clay and silt fractions of both soils were significantly greater under high than under low N deposition. Since clay- and silt-bound SOM consists of humified compounds, this indicates that N addition retarded mineralisation of old and humified SOM, [which] accounted for 60-80 g C m-2 4yr-1, which corresponds to about 40% of the old SOM mineralised in these fractions. As a consequence, preservation of old and humified SOM under elevated N deposition might be a process that could lead to an increased soil C storage in the long-term. |
| 1006 | Hagmeier, H.U. | M?glichkeiten und Probleme der N-Akkumulation durch Leguminosen und der NVerwertung in einem nach biologischen Gesichtspunkten bewirtschafteten Betrieb | 1980 | Green Manure; Stockless Farming | Book | Hagmeier, H.U.; Möglichkeiten und Probleme der N-Akkumulation durch Leguminosen und der N-Verwertung in einem nach biologischen Gesichtspunkten bewirtschafteten Betrieb; | English | Hardcopy:Partial | The defining characteristics of organic cultivation are considered. Among them are: care of the living organisms in the soil, the maintenance of SOM content with materials originating within the holding, the maintenance of soil N content mainly through microbial fixing of atmospheric N and the production of healthy, high quality food. Careful consideration is necessary before all cultivation measures, especially of their long-term consequences. The soil should be kept covered at all times. | Im Mittelpunkt aller Betrachtungen steht bei diesem Landbausystem derBoden.; .. bei allen Kulturmanahmen [ist] eine wohlueberlegte Vorgehenweise erforderlich.; Die meisten acker- und pflanzenbaulichen Entscheidungen haben hier laengerfristige Bedeutung. Bei der Entscheidungsfindung sollte daher versucht werden, zu erwartende positive und negative Haupt- und Nebenwirkungen moeglichst weit vorauszusehen. |
| 1632 | Hagmeier, H.U. | Ueber die Stickstoffversorgung von Winterweizen und Winterroggen durch Leguminosenvorfruechte, dargestellt anhand von Expt.en auf einem viehlos bewirtschafteten organischbiologischen Ackerbaubetrieb auf der Schwbischen Alb | 1986 | Stockless Farming | Book | Hagmeier, H.U.; Ueber die Stickstoffversorgung von Winterweizen und Winterroggen durch Leguminosenvorfruechte, dargestellt anhand von Expt.en auf einem viehlos bewirtschafteten organischbiologischen Ackerbaubetrieb auf der Schwbischen Alb; | German | Hardcopy:Partial | Expt. to test whether preceding leguminous green crops could supply the N requirements of a following winter wheat crop. Three different green crops were tried: lucerne (undersown into the preceding year's rye crop), field beans undersown with a grass/clover and two successive crops of field beans in the same season. The green crops were cut three times in the season and either removed from the field or mulched on it. The lucerne and the double bean crop gave rise to equally high N accumulation (reflected in the following cereal yields), while the single bean crop was somewhat lower. There was a higher total N accumulation when the cut material from the green crop was removed than when it was cut-and-mulched. | |
| 536 | Haidar, M.A., Bibi, W. & Sidahmed, M.M. | Response of branched broomrape (Orobanche ramosa) growth and development to various soil amendments in potato | 2003 | Lignin and CBW; Potato Growing | Journal | Crop Prot.; 22; 291-294 | English | Hardcopy:Full; PDF:Full | Field expt. to test the capacity of various fertilisers to suppress the growth of broomrape - a weed in potato fields in Lebanon. The control (unamended) plot gave a potato yield of 22,220 kg/ha. The other treatments gave similar yields except the wood chips, which yielded only about half that. | The treatments were broiler, cattle, goat, layer [and] sheep manure and wood chips.; None of the treatments except wood chips were phytotoxic to potato plants. |
| 1620 | Haider, K. | Von der toten organischen Substanz zum Humus | 1999 | Lignin and CBW; Soil Organic Carbon | Journal | Z. Pflanz. Bodenkunde; 162; 363-371 | German | Hardcopy:Full | Review of current knowledge of plant residue decay in soil. Less humified residues can be stabilised by sorption, by complex'n with metal oxides or by spatial sequestration on the surfaces of or inside the inorganic particle fraction or in aggregates. In relation to the total global SOC, total atmospheric CO2-C is 50%, total plant biomass C is 40%, annual plant biomass incorporation into the soil is 4% & total microbial biomass is 2%. Within a year in temperate climates, 60-70% of leaves or straw are mineralised to CO2, but only 30% of lignin. The C/N ratio of SOM decreases with decreasing particle size. In a chernozem 60% of the org. N is in the clay fraction (<2m). Allophanic soils have a relatively higher SOM content, as the OM is bound to Al3+ ions. Mean residence times of SOM varies from 0.5 yr for coarse plant material to >1000 yr for SOM in fine clay. The SOM sorbed onto clay consists mainly of aliphatic compounds, especially those of protein origin. The tannins, phenolic and other lignin residues are found mainly in the silt fractions. Lignin degradation is aerobic and co-metabolic, requiring a supplementary labile C source. It is considered by some to take place rapidly, giving products that are re-polymerised into recalcitrant OM, and by others to take place slowly and continuously, giving intermediate products that are protected by attachment to mineral particles. | Die Huminstoffe des Bodens bestehen .. aus Produckten eines kontinuierlichen Fberganges von nur wenig vernderten aber rumlich stabilisierten pflanzlichen Inhaltsstoffen bis hin zu zunehmend inerten Strukturen, die aber ebenfalls zustzlich durch sorptive und komplexierende Reaktionen stabilisiert sein k?nnen. |
| 1545 | Hajabbasi, M.A. & Hemmat, A. | Tillage impacts on aggregate stability and crop productivity in a clay-loam soil in central Iran | 2000 | Soil (General); Tillage | Journal | Soil Tillage Res.; 56 (3-4); 205-212 | English | Hardcopy:Partial; Wordperfect:Full | Field expt. to study the effect of different tillage treatments on the soil and crop yields. Initial SOC content of soil - 0.94% | After 4 years .. a decrease of 11% in SOC in the conventional tillage treatment (MD) was observed .. while an increase of 4 and 2% of organic C in the non-inversion .. and CR [chisel-ploughing + rotary tilling] tillage treatments were seen respectively.; Although direct drilling improved soil structural `stability, its lower yield (5608 and 4731 kg ha-1 for TP and NT respectively) potential would indicate that reduced tillage systems (i.e. CD [chisel-ploughing and discing]) appear to be the accepted alternative management compared to conventional practice. |
| 108 | Hall, C.W. | Mechanisation and Food Availability | 1989 | Energy in Agriculture | Book | Pimentel, D. & Hall, C.W. (eds.); Food and Natural Resources; | English | Hardcopy:Partial | Impact of mechanisation on agriculture. A table from Pimentel and Pimentel (1979) shows the energy input needed to till soil by hand, oxen and tractors. Two graphs from Steinhart and Steinhart (1975) relate the energy use on farms to the labour use and to the energy content of the food produced. | |
| 1663 | Hall, C.W. & Pimentel, D. | Food and Natural Resources | 1989 | Agricultural Ecology | Book | Hall, C.W. & Pimentel, D.; Food and Natural Resources; | English | Hardcopy:Partial | See under Hall, C.W. (1989) | |
| 735 | Hamer, U. & Marschner, B. | Priming effects in soils after combined and repeated substrate additions | 2005 | Priming Effect | Journal | Geoderma; 128; 38-51 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the primingeffect on soil after multiple substrate additions | .. the combined substrate addition induced stronger positive priming than the single additions. .. Since priming effects were not depressed after extended pre-incubation of a soil sample, it seems unlikely that only the labile SOC-pool is susceptible. Co-metabolism and the turnover of native microbial biomass are insufficient to explain the observed positive priming effects. |
| 1238 | Hamer, U. & Marschner, B. | Priming effects in different soil types induced by fructose, alanine, oxalic acid and catechol additions | 2005 | Priming Effect | Journal | Soil Biol. Biochem.; 37 (3); 445-454 | English | Hardcopy:Partial; Wordperfect:Full | Lab. expt. to study the primingeffect on soil after multiple substrate additions | The strongest positive priming effects were induced by fructose and alanine.. these substrates enhanced SOC mineralisation by +10% to [ca.90]%. Catechol additions generally reduced SOC mineralisation by -12% to -43%.; .. priming effects are ubiquitously occurring in surface and subsoil horizons of forest soils as well as in arable soils.; .. positive priming effects are most pronounced in forest soils that contain SOC of low biodegradability, where the added substrates may act asan important energy source for microbial metabolism. |
| 981 | Hamer, U., Marschner, B., Brodowski, S. & Amelung, W. | Interactive priming of black carbon and glucose mineralisation | 2004 | Priming Effect; Soil Organic Carbon | Journal | Org. Geochem.; 35; 823-830 | English | Hardcopy:Partial; PDF:Full | Expt. to study the biodegradation in soil of charred wood and crop residues and the effect of added glucose. Charred plant materials can constitute from 35-60% of the SOM in black soils (chernozems). | Black C (BC) is produced by incomplete combustion of fossil fuels and vegetation and occurs ubiquitously in soils and terrestrial sediments. It is relatively inert and thus contributes to refractory SOM; The charred materials in our study were as degradable as SOM ..; wood-decaying fungi that were able to degrade low-rank coals .. the presence of a second, easily available, C source was required to induce microbial degradation of brown coal. .. co-metabolism might be a major pathway of BC degradation. In general, organic substrates are considered to be degraded co- metabolically if another C source is required by microorganisms for their degradation.; Mineralisation of BC is stimulated by glucose addition. The second glucose additions exhibits a stronger priming effect on BC degradation than the first, because of a better adaptation of the microorganisms to BC decay. |
| 18 | Hammel, K.E. | Fungal degradation of lignin | 1997 | Lignin and CBW; Soil Microorganisms | Book | Cadisch, G. & Giller, K.E. (eds.); Driven by Nature: Plant Litter Quality and Decomposition. C.A.B. International; | English | Hardcopy:Partial; Wordperfect:Full | Review of the biodegradation of lignin | Fungi that degrade lignin are faced with several problems. Since the polymer is extremely large and highly branched, ligninolytic mechanisms must be extracellular. Since it is interconnected by stable ether and carbon-carbon bonds, these mechanisms must be oxidative rather than hydrolytic. Since lignin consists of a mixture of stereo-irregular units, fungal ligninolytic agents have to be much less specific than typical biological catalysts. |
| 1654 | Hammond, A.L., Metz, W.D. & Maugh, T.H. | Energy and the Future | 1973 | Energy Resources | Book | Hammond, A.L., Metz, W.D. & Maugh, T.H.; Energy and the Future; | English | Hardcopy:Partial | Alternative energy sources in the United States are reviewed. Estimates are made of the renewable and depletable energy resources of the United States, | The world's total hydroelectric power is estimated to be three billion kilowatts, of which only 8.5 per cent is developed. |
| 1038 | Handayanto, E., Cadisch, G. & Giller, K.E. | Nitrogen release from prunings of legume hedgerow trees in relation to quality of the prunings and incubation method | 1994 | Mineralisation; Mulch; Soil N Dynamics | Journal | Plant Soil; 160; 237-248 | English | Hardcopy:Partial | Lab. expt. to study the decomposition of residues from leguminous trees | Alley cropping is an agroforestry system in which food crops are grown between rows of .. preferably N-fixing trees, which are periodically pruned to prevent shading .. and to reduce competition with the food crops.; .. the synchronisation of N release from decomposing plant residues with crop demand for N is critical for the successful use of such approaches.; The critical N content .. for immediate net mineralisation of N to occur was .. 1.73% and the critical C/N ratio was 20.; .. the protein-binding capacity of the polyphenols played an important role in N release from the prunings ..; .. lignin is also capable of reducing the availability of both carbohydrates and protein by complexing them. |
| 1239 | Handayanto, E., Giller, K.E. & Cadisch, G. | Regulating N release from legume tree prunings by mixing residues of different quality | 1997 | Mineralisation; Mulch; Soil N Dynamics | Journal | Soil Biol. Biochem.; 29 (9/10); 1417-1426 | English | Hardcopy:Full; PDF:Full | Lab. expt. to study the rate of N mineralisation from a mixture of prunings from two tree species, one high and one low quality, showing that the rate can be manipulated by altering the proportion in the mixture. The effect was to reduce not only the rate of N release but also the total amount of N released from the prunings over a 3-month period. | .. the quality .. best related to N release under leaching conditions was the (lignin+polyphenol)/N ratio, whereas under non-leaching conditions the proteinbinding capacity gave the [best]; .. mixing residues that contained little polyphenols but had varying N & lignin contents have resulted in intermediate rates of decompos'n .. mixing of Gliricidia residues with rice straw led to delayed N release, but the total amount of N mineralised was not altered. |
| 309 | Hannah, L., Lohse, D., Hutchinson, C., Carr, J.L. & Lankerani, A. | A preliminary inventory of human disturbance of world ecosystems | 1994 | Sustainability | Journal | Ambio; 23 (4-5); 246-250 | English | Hardcopy:Full | The human impact on the biosphere is assessed. A mapping of human intervention in natural ecosystems is presented. | .. the study .. examine[s] all natural areas of potential importance for conservation ..; This study has not addressed diversity, endemism or rate of destruction .. |
| 224 | Hansen, B., Alrøe, H.F. & Kristensen, E.S. | Approaches to assess the environmental impact of organic farming with particular regard to Denmark | 2001 | Energy in Agriculture; Organic Farming; Soil N Dynamics | Journal | Agric. Ecosyst. Environ.; 83; 11-26 | English | Hardcopy:Partial; PDF:Full | Review of energy use and effects on soil and environment in organic farming | .. the risk of harmful environmental effects is lower with organic than with conventional farming methods, though not necessarily so.; In most cases there is .. a lower surplus of nutrients & less leaching with organic than with conventional farming. However, poor mgmnt (e.g. the ploughing of grass and legumes at the wrong time of year with no subsequent crops to capture the mineralised nitrogen) .. can lead to a high level of leaching in some organic systems.; .. a transition to 100% organic farming would result in a 9-51% reduction in the net consumption of fossil energy... The decrease in (i) agricultural energy consumption, (ii) N turnover and (iii) animal production in a 100% organic Denmark would produce a corresponding decrease (13-38%) in the national emission of H greenhouse gases (CO2, CH4, N2O). |
| 615 | Hansen, B., Kristensen, E.S., Grant, R., Høgh-Jensen, H., Simmelsgaard, S.E. & Olesen, J. | Nitrogen leaching from conventional versus organic farming systems - a systems modelling approach | 2000 | Soil N Dynamics | Journal | Eur. J. Agron.; 13; 65-82 | English | Hardcopy:Partial; PDF:Full | Modelling nitrate leaching in conventional and organic farming systems | |
| 181 | Hansen, J.W. | Is agricultural sustainability a useful concept? | 1996 | Sustainability | Journal | Agric. Sys.; 50; 117-143 | English | Hardcopy:Partial | Barriers to using sustainability as a criterion for guiding change in agriculture are examined. Sustainability is considered from four points of view - as an ideology, as a set of strategies for managing agricultural systems, as the ability to fulfil a set of goals - generally including environmental soundness and financial viability, and as the ability to continue indefinitely. | Literal interpretations of sustainability as an ability to continue into the future suggest measurable integrated criteria for its characterisation. However, applications of these criteria - time trends and resilience - have neglected or misinterpreted important aspects of system performance that influence sustainability. .. In order for sustainability to be a useful criterion for guiding change in agriculture, its characterisation should be literal, systemoriented, quantitative, predictive, stochastic and diagnostic. |
| 182 | Hansen, J.W. & Jones, J.W. | A systems framework for characterising farm sustainability | 1996 | Sustainability | Journal | Agric. Sys.; 51; 185-201 | English | Hardcopy:Partial | Sustainability in agriculture is compared with other dynamic stochastic processes. It can be expressed as the probability of continuation within specified threshold boundaries through a specified future period. It is defined and quantified using the proposed framework. | To sustain is literally to keep in existence; keep up; maintain or prolong .. Sustainability can therefore be defined as the ability of a system to continue into the future.; .. the concept of sustainability can be applied to any system that is dynamic, stochastic and purposeful. .. sustainability has no meaning unless some .. threshold condition exists which distinguishes a system that is sustaining from one that has failed.; .. the ability of a system to continue in the future is best expressed as a probability .. with a zero-to-one range that addresses the question, 'With what degree of certainty will the system sustain?' |
| 863 | Hansen, N.C., Daniel, T.C., Sharpley, A.N. & Lemunyon, J.L. | The fate and transport of phosphorus in agricultural systems | 2002 | Phosphorus Cycling | Journal | J. Soil Water Conserv.; 57 (6); 408-417 | English | Hardcopy:Full | Review of research into phosphorus cycling in agricultural ecosystems. There are three hypothetical pools of soil phosphorus: soluble P (orthophosphate anions); reactive P, consisting of organic P (fresh OM) and inorganic P (on anion exchange sites) in dynamic equilibrium with dissolved P; and stable P, consisting of organic and inorganic P that is occluded, insoluble or tightly sorbed. Soil test P (STP) includes soluble P and part of reactive P. When no P fertiliser is applied, total P and STP of soils averaged about 400 mg kg-1 and `12 mg kg-1 respectively, making STP around 3% of total P. Under annual cropping (removing about 8 kg ha-1 yr-1, STP declined at rates of only 1.6 and 2.9 mg kg-1 yr-1 when the initial STP level was 20 and 40 mg kg-1 respectively, showing that some P was being mineralised in the soil, but not enough to sustain cropping. | .. loss of BAP [bio-available phosphorus] from agricultural watersheds was approximately three times less with no tillage than with conventional tillage.; Soil have a finite P sorption capacity, which varies [with] clay content, clay type, OM content, concentration of exchangeable Al, Fe & Ca and soil pH.; The P saturation expresses the percent of the P sorption capacity that is filled.; When the P saturation is high, a larger percentage of the applied P remains in forms extracted by STP methods than for soils with a low percent of P saturation.; Addition of organic amendments to soils can reduce the P sorption capacity .. |
| 1240 | Hansen, S., Maehlum, J.E. & Bakken, L.R. | N2O and CH4 fluxes in soil influenced by fertilisation and tractor traffic | 1993 | Greenhouse Gases; Soil N Dynamics | Journal | Soil Biol. Biochem.; 25 (5); 621-630 | English | Hardcopy:Partial | Expt. to study the effect of fertiliser and tractor traffic on the soil N2O and CH4 fluxes | x; Concentrations of N2O in soil air were more than seven times higher in compacted @NPK-fertilised soil than in any other treatments. .. The accumulated N2O emissions from the NPK-fertilised treatment (4 June-8 July) corresponded to 5.3% of added NH4NO3-N in compacted soil and 3.9% in uncompacted soil. Fertilisation with cattle slurry equivalent to 81 kg total N ha-1 gave an N2O emission `corresponding to 3.1% of added NH4-N in uncompacted soil and 2.7% in compacted (soil. .. The accumulated CH4 uptake (4 June-8 July) in the soil was 9.7 mg CH4 m-2 in unfertilised and uncompacted soil. It was reduced by 52% by soil compaction, 50% on average by fertilisation and 78% by soil compaction and fertilisation combined. |
| 425 | Hanson, P.J., Edwards, N.T., Garten, C.T. & Andrews, J.A. | Separating root and soil microbial contributions to soil respiration: a review of methods and observations | 2000 | Roots & Rhizodeposition | Journal | Biogeochemistry (Dordr.); 48 (1); 115-146 | English | Hardcopy:Partial; PDF:Full | Review of experimental methods to measure root and microbial contributions to total soil respiration | .. root/rhizosphere respiration can account for as little as 10 percent to greater than 90 percent of total in situ soil respiration depending on vegetation type and season of the year. Studies which have integrated percent root contribution to total soil respiration throughout an entire year or growing season show mean values of 45.8 and 60.4 percent for forest and non-forest vegetation respectively. .. the root contribution to total soil respiration is commonly higher during the growing season and lower during the dormant periods of the year. |
| 821 | Hao, X.Y., Chang, C., Larney, F.J. & Travis, G.R. | Greenhouse gas emissions during cattle feedlot manure composting | 2001 | Compost & Biocontrol; Greenhouse Gases | Journal | J. Environ. Qual.; 30; 376-386 | English | Hardcopy:Partial; Wordperfect:Full | Expt. to determine whether greenhouse gas emissions during composting are affected by the composting method - active (turned over) or passive (no turning) | x; C lost in the forms of CO2 and CH4 was 73.8 and 6.3 kg C Mg-1 manure for the @passive aeration treatment and 168.0 and 8.1 kg C Mg-1 manure for the active treatment. The N loss in the form of N2O was 0.11 and 0.19 kg N Mg-1 manure for the passive and active treatments. Fuel consumption to turn and maintain the windrow added a further 4.4 kg C Mg-1 manure for the active aeration treatment. `Since CH4 and N2O are 21 and 310 times more harmful than CO2 in their global (warming effect, the total GHG emission expressed as CO2-C equivalent was 240.2 and 401.4 kg C Mg-1 manure for passive and active aeration.; Several mechanisms, including nitrification, denitrification and chemo-denitrification, could all potentially contribute to the observed N2O profiles and surface emission H patterns. .. At the beginning, with high NH4+ and low NO3- concentration in the feedlot manure, nitrification rather than denitrification is the major contributor to the increased N2O concentration ..; Conversion of NO2- to NO3- is inhibited by high temperatures, .. high NH4+ content and high pH.; .. denitrification occurs under anaerobic conditions. |
| 836 | Hao, X.Y., Chang, C., Travis, G.R. & Zhang, F.R. | Soil carbon and nitrogen response to 25 annual cattle manure applications | 2003 | Stockless Farming; Soil N Dynamics | Journal | J. Plant Nutr. Soil Sci.; 166 (2); 239-245 | English | Hardcopy:Partial | Field expt. to study the long-term effects of FYM application to soil | For every ton of manure OC added, soil OC increased by 0.181 g kg-1 in the topsoil (0-15 cm)... for every ton of manure TN added, surface soil TN increased @by 0.192 g kg-1. The linear relationship between manure C added & soil C content suggests that the soil had a high capacity for short-term C sequestration. |
| 1386 | Hao, Y., Lal, R., Izaurralde, R.C., Ritchie, J.C., Owens, L.B. & Hothem, D.L. | Historic assessment of agricultural impacts on soil and soil organic carbon erosion in an Ohio watershed | 2001 | Soil Organic Carbon; Soil (General); Tillage | Journal | Soil Sci.; 166 (2); 116-126 | English | Hardcopy:Partial | Soil erosion of plots under conventional and zero tillage and under different rotations was assessed using sediment collection, the caesium-137 exponential equation and the RUSLE methods. It was concluded that the sediment method was the best. The caesium-137 method gave results from 1 to 3 times greater. The RUSLE method gave results 3 to 14 times greater than sediment collection. A ley course gave the lowest erosion rate (zero). The worst was continuous maize. Zero tillage gave much less erosion than any of the ploughed plots. | |
| 325 | Harder, W. & Dijkhuizen, L. | Physiological responses to nutrient limitation | 1983 | Soil Microorganisms | Journal | Annu. Rev. Microbiol.; 37; 1-23 | English | Hardcopy:Full | Review of the ways in which microorganisms respond to limitations in the major nutrients: C, N, P, S, K and Mg. These responses are of 3 types: to increase the rate of transport of the nutrient, to increase the rate of initial metabolism of the nutrient and to rearrange the chemical composition of cellular structures by re-directing fluxes of metabolites containing the nutrient. During C limitation diversion of C into extracellular products is minimised, favouring catabolism to anabolism. | .. the flux of non-limiting C source is generally not tightly balanced to biomass formation and this may lead to a significant accumulation of intracellular reserve materials, extracellular polymers or a variety of low-molecular-weight metabolites.; Phosphate limitation may also have a marked effect on the production of exoenzymes by certain bacteria. |
| 1113 | Harmon, M.E., Ferrell, W.K. & Franklin, J.F. | Effects on carbon storage of conversion of old-growth forests to young forests | 1990 | Greenhouse Gases; Soil Organic Carbon | Journal | Science; 247; 699-702 | English | Hardcopy:Partial | Simulation of C storage by forests. Of harvested wood 15% is left behind as broken or defective, 9% is bark, 30% is lost to sawdust or scrap and only about 42% enters long-term storage such as structural components of buildings. | .. of the 325 Mg of C per ha harvested from a typical old-growth forest 187 Mg of C per ha may be lost to the atmosphere ..; During simulated timber harvest on-site C storage is reduced considerably and does not approach old-growth storage capacity for at least 200 years. .. timber harvest results in a net flux `of CO2 to the atmosphere. |
| 183 | Harris, D., Pathan, A.K., Gothkar, P., Joshi, A., Chivas, W. & Nyamudez, P. | On-farm seed priming: using participatory methods to revive and refine a key technology | 2001 | Miscellaneous | Journal | Agric. Sys.; 69 (1/2); 151-164 | English | Hardcopy:Partial | Farm trials of maize, rice, sorghum and chickpeas comparing soaked seed with dry seed were carried out in India and Zimbabwe. Soaked seed gave significantly better results. | In each trial farmers were asked to soak seed overnight, surface-dry it then sow it in the normal way in a plot next to a plot with dry seed.; Direct benefits in all crops included: faster emergence; better, more uniform stands; less need to re-sow; more vigorous plants; better drought tolerance; earlier flowering; earlier harvest; and higher grain yield. |
| 292 | Harris, G.H. & Hesterman, O.B. | Quantifying the nitrogen contribution from alfalfa to soil and two succeeding crops using nitrogen-15 | 1990 | Soil N Dynamics | Journal | Agron. J.; 82; 129-134 | English | Hardcopy:Full | Field expt. to study the uptake of lucerne-N by maize followed by spring barley. Nearly half the N from the lucerne remained in the soil, nearly all as organic N. Nearly a fifth of this was microbial biomass. About a third of the lucerne-N was lost from the system, probably by denitrification and leaching. Of the 115 kg N/ha applied as lucerne, 24 and 51 kg/ha are taken up by the maize and stored in the soil respectively. | |
| 293 | Harris, G.H., Hesterman, O.B., Paul, E.A., Peters, S.E. & Janke, R.R. | Fate of legume and fertiliser nitrogen-15 in a long-term cropping systems experiment | 1994 | Soil N Dynamics | Journal | Agron. J.; 86; 910-915 | English | Hardcopy:Full | 2-year field expt. using 15N to compare the dynamics in soil of chemical and symbiotically fixed N. The quantities of N recovered in crops and retained in the soil were 40% v. 17% and 17% v. 47% for chemical fertiliser and legume respectively. The average total N loss was around 39% for both sources, but the losses in the first and second years were 38% v. 18% and 4% v. 17% for chemical fertiliser and legume respectively. | Soil microbial biomass was larger in the legume-based than in the fertiliserbased system, but specific respiratory activity was the same. |
| 1241 | Harrison, K., Bol, R. & Bardgett, R. | Do plant species with different growth strategies vary in their ability to compete with soil microbes for chemical forms of nitrogen? | 2008 | Soil Microorganisms | Journal | Soil Biol. Biochem.; 40; 228-237 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to determine whether a plant's capacity to take up N depended on whether it was fast- or slow-growing | @; .. we detected no difference in microbial biomass or microbial uptake of 15N between fast & slow-growing plant species, suggesting that plant traits that regulate nutrient capture, as opposed to plant species-specific interactions with soil microbes, a |
| 61 | Hartl, W., Kromp, B., Erhart, E., Huspeka, C., Meindl, P., Putz, B. & Schwaiger, E. | Neues Bewirtschaftungssystem im oekologischen Feldbau: Evaluierung der agraroekologischen Auswirkungen der 'pfluglosen Mulch-Streifenmischkultur, System Edinger' | 1999 | Mulch; Organic Farming | Book | Hofmann, H. & Mueller, S. (hgbr); Vom Rand zur Mitte: Beitraege zur 5. Wissenschaftstagung zum oekologischen Landbau, Berlin; | German | Hardcopy:Partial | Expt. to compare the Edinger system with conventional cultivation. The mulched beds showed a higher N and moisture content, greater earthworm and arthropod populations. | Aus pflanzenbaulicher Sicht mu es jedoch noch in Hinblick auf die maschinelle Bewirtschaftung, Beerntung und die Bestandesfuehrung von Kultur- und Begruenungspflanzen optimiert werden. |
| 829 | Hartwig, U.A., Wittman, P., Braun, R., Hartwig-Räz, B., Jansa, J., Mozafar, A., Lüscher, A., Leuchtmann, A., Frossard, E. & Nösberger , J. | Arbuscular mycorrhiza infection enhances the growth response of Lolium perenne to elevated atmospheric pCO2 | 2002 | Greenhouse Gases | Journal | J. Exp. Bot.; 53; 1207-1213 | English | Hardcopy:Partial | Expt.s to compare the biomass of perennial ryegrass plants under elevated atmospheric CO2 concentrations with low and high soil N concentrations and with or without innoculation with AM fungi. | Elevated CO2 increased plant biomass by 10% and 17% at low and high levels of soil N respectively. .. at high soil N the presence of symbiotic fungus more `than doubled the plant growth response to atmospheric CO2 enrichment [to 41%]. |
| 1039 | Hassink, J. | The capacity of soils to preserve organic C & N by their association with clay and silt particles | 1997 | Soil Organic Carbon; Soil N Dynamics | Journal | Plant Soil; 191 (1); 77-87 | English | Hardcopy:Partial; PDF:Full | Expt. to compare the quantity of clay- and silt-associated C and N in arable, grassland and uncultivated soils and to quantify the C & N protected by this association | .. the amounts of C & N that can be associated with clay and silt particles [are] limited .. C (g kg-1) = 4.09 + 0.37 x %particles<20 m; N (g kg-1) = 0.40 + 0.037 x %particles<20 m;; .. although the .. arable soils contained less C & N than the corresponding grassland soils, the amounts of C & N associated with clay and silt particles was the same, indicating that the amounts of C & N that can become associated with this fraction had reached a maximum.; [There were] close positive relationships between the proportion of primary particles <20 m in a soil and the amounts of C & N that were associated with this fraction in the top 10 cm of soils .. The observed relationships were assumed to estimate the capacity of a soil to preserve C & N by their association with clay and silt particles.; The amount of C & N in the fraction >20 m was not correlated with soil texture. Cultivation decreased the amount of C & N in the fraction >20 m to a greater extent than in the fraction <20 m, indicating that C & N associated with the fraction <20 m is better protected against decomposition. |
| 1242 | Hassink, J. | Relationship between the amount and the activity of the microbial biomass in Dutch grassland soils: comparison of the fumigation-incubation method and the substrate-induced respiration method | 1993 | Soil Microorganisms | Journal | Soil Biol. Biochem.; 25 (5); 533-538 | English | Hardcopy:Partial | Field expt. to assess whether soil texture and available C affect microbial activity | The ratio biomass-SIR:biomass-FI, indicating the percentage of active microbial biomass, and the ratio C mineralisation:biomass-FI, indicating the activity of the microbial biomass, were both higher in soils with a coarse texture than in soils with a fine texture.. []and] were higher in the upper 10-cm soil layer than in the 10-25-cm layer ..; .. the percentage of active microbial biomass is lower in soils with a fine texture than in sandy soils. This may be caused by the higher grazing pressure of soil fauna on bacteria in soils with a coarse texture... faunal grazing may keep the microbial population in a metabolically more active state. As the volume of a population under grazing pressure always remains under its carrying capacity, rate-limiting factors such as availability of nutrients or energy will be removed and a higher proportion of the population may be active.; Clay particles .. have a stabilising effect on microbial biomass .. This protection capacity .. (e.g. in small pores and on clay surfaces) .. refers to the total microbial biomass. The active biomass is much less protected than the total biomass. |
| 1243 | Hassink, J. | Effects of soil texture and grassland management on soil organic C & N and rates of C & N mineralisation | 1994 | Mineralisation; Soil Organic Carbon; Soil N Dynamics | Journal | Soil Biol. Biochem.; 26 (9); 1221-1231 | English | Hardcopy:Partial | Field expt. to measure the effects of soil texture and grassland management on the soil C & N dynamics | The decomposition rate if organic residues ,.. is typically lower in finetextured soils than in coarse-textured soils.; [but]; .. soil texture was not always the dominant factor determining the org. C content .. and C mineralisation rates. Differences in C/N ratio of the SOM and the groundwater table confused the relationship .. The residues of heathland generally have a high C/N ratio. .. Differences in C/N ratio might also result from the presence of inert charcoal .. sandy soils with a high C/N ration contained more inert C than other soils.; Differences in fertiliser N were found not to affect the amount of SOC & N.; .. the amounts of soil C & N and rates of C & N mineralisation were often not significantly different between mowing and grazing. |
| 1244 | Hassink, J. | Effects of soil texture on the size of the microbial biomass and the amount of C & N mineralised per unit of microbial biomass in Dutch grassland soils | 1994 | Mineralisation; Soil Microorganisms | Journal | Soil Biol. Biochem.; 26 (11); 1573-1581 | English | Hardcopy:Partial | Field expt. to investigate the relationship between soil microbial biomass and the rate of C & N mineralisation. | .. in the sandy soils and loams the amounts of microbial biomass were approximately twice as high as the amounts of bacterial biomass, while in the clays they were more than three times as high.; The differences in C/N ratio of the microbes between sandy soils, loams and clays were not caused by differences in the fraction of fungi in the microbial biomass, as this was found to be very small in both sandy soils as well as in loams and clays. |
| 1245 | Hassink, J. | Density fractions of soil macroorganic matter and microbial biomass as predictors of C & N mineralisation | 1995 | Mineralisation; Soil Organic Carbon; Soil Microorganisms | Journal | Soil Biol. Biochem.; 27 (8); 1099-1108 | English | Hardcopy:Full | Analysis of soils from arable and grassland to investigate the correlation between mineralisation rates and SOM in different size-density fractions. Bare soil was compared with soils amended with chaff, lucerne and FYM. | For all residue treatments the C/N ratios of OM decreased in the order light, intermediate, heavy macro-OM (fraction >150 m) and non-macro-OM (fraction <150 m).; C & N mineralisation were positively correlated with the amount of C & N in the light fraction and the active microbial biomass. .. C & N mineralisation per unit of total microbial biomass were lower in fine-textured soils than in coarse-textured soils. This is ascribed to a greater physical protection of the OM in fine-textured soils than in coarse-textured soils.; The largest increase in SOC was found in the FYM treatment, which caused a 5.9-fold increase in the sandy soil and a 3.6-fold increase in the clay soil in comparison with bare soil. |
| 1430 | Hassink, J. | Decomposition rate constants of size and density fractions of soil organic matter | 1995 | Mineralisation; Soil Organic Carbon | Journal | Soil Sci. Soc. Am. J.; 59 (6); 1631-1635 | English | Hardcopy:Full | Expt.s to study the decomposition rates of OM fractions from different soil types. Five fractions were studied - two microaggregate size fractions (< 20 m and between 20 and 150 m) and three density fractions of OM between 150 and 250 m. The decomposition rates for each fraction did not differ much between different soil types. The rates for the microaggregate size fractions were very low and similar to the rate for total soil C. | Mineralisation of C .. decreased in the order light > intermediate > heavy macro-OM.; .. the rate constants for decomposition decreased in the order light (0.24% d-1) > intermediate (0.098% d-1) > heavy (0.036% d-1) ..; The percentage of soil C present in the light, intermediate and heavy macro-OM fractions in the top 10 cm of grassland soils were 1.5, 5 and 13% respectively. therefore about 80% of the total amount of soil C was present in microaggregates. |
| 1431 | Hassink, J. | Preservation of plant residues in soils differing in unsaturated protective capacity | 1996 | Soil Organic Carbon | Journal | Soil Sci. Soc. Am. J.; 60 (2); 487-491 | English | Hardcopy:Full | Expts. using 14C as a tracer to test the hypothesis that the amount of newlyadded OM preserved by a soil depends not only on the texture of the soil (soils rich in clay and silt preserving more OM than sandy soils) but also on the degree to which the protective capacity of the clay and silt is already saturated with OM. The amount of newly-added C is said to be related to the soil characteristics by the equation:% of applied C associated with the fraction < 20 m = 6.72 + 0.23 x % of soil particles < 20 m + 0.67 x the saturation deficit.The soils used in the expt. had SOC contents of 0.5-4.3% and microbial biomass of 0.001-0.077%. | During the first 3 days after the application of 14C considerable differences H in 14CO2 production between soils were found that were significantly correlated with the saturation deficit but not with soil texture.; During the first weeks after application most of the 14C applied is either soluble or in the sand-size fraction. With extended incubation most of the preserved 14C has been reported hto associate with clay and silt particles. The microbial 14C may then consist of 0both newly synthesised, not yet stabilised microbial 14C and microbial 14C that is associated with clay and silt particles. |
| 1040 | Hassink, J. & Dalenberg, J.W. | Decomposition and transfer of plant residue 14C between size and density fractions in soil | 1996 | Soil Organic Carbon | Journal | Plant Soil; 179; 159-169 | English | Hardcopy:Partial | Lab. expt. to study the movement of SOM from one soil fraction to another. 65% & 90% of the SOC was found in microaggregates in sandy soil & loam respectively. | .. all plant residues (except lignin-like components) that enter the soil must pass [through] the microbial biomass, [which] partly mineralises them [and] partly converts the residues into new products ..; .. material derived from the grass decomposed much faster than soil-derived C recovered in the same `fractions.; .. there must have been a transfer of 14C from the most labile (fractions (.. the light macro OM fraction, soluble 14C and microbial 14C) to the intermediate macro OM fraction during the first few days after 14C application & to the heavy macro OM fraction during the first weeks after this application.; .. microaggregates contain a large proportion of the most stable OM in soil and protect OM.; .. the binding of organics to mineral particles (leading to the formation of heavy material) can take place very quickly.; .. the decomposition rate of plant-derived C associated with the microaggregate fraction <20 m is affected by the degree of saturation of the protective sites with SOM .. |
| 1432 | Hassink, J. & Whitmore, A.P. | A model of the physical protection of organic matter in soils | 1997 | Soil Organic Carbon | Journal | Soil Sci. Soc. Am. J.; 61 (1); 131-139 | English | Hardcopy:Partial | Modelling the physical protection of OM as a function of the capacity of clay particles and aggregates to hold OM | .. the physical capacity of a soil to preserve OM is limited. .. the degree of saturation of the protective capacity of a soil with OM would affect the preservation of newly added C in residues. Less of the applied C should be preserved in a soil when all the protective sites were occupied than when sites were available to stabilise organic C.; .. part of the protection being afforded to OM in soils was not related to the clay content of the soil. Between one third and one half of the total protection of OM in clay-rich soils appears to be independent of clay content. This additional protection may occur thorough the stabilisation of OM by organic or ferritic soil colloids or chemical stabilisation ..; .. there is probably a continuum from non-protected to completely protected OM. |
| 1246 | Hassink, J., Bouwman, L.A., Zwart, K.B. & Brussaard, L. | Relationships between habitable pore space, soil biota and mineralisation rates in grassland soils | 1993 | Mineralisation; Soil Microorganisms | Journal | Soil Biol. Biochem.; 25 (1); 46-55 | English | Hardcopy:Partial | Field expt. to investigate the relationships between pore size, microbial and microfaunal populations and mineralisation rates | .. in loams and clays most pores had diameters <1.2 m, whereas in sandy soils most pores had diameters from 6 to 90 m. A close positive correlation was found between the bacterial biomass and the .. pores with 0.2-1.2 m dia. and between the biomass of nematodes & the .. pores with 30-90 m dia. The biomass of fungi and protozoa showed no relationship with .. pore-size .. |
| 1247 | Hassink, J., Neutel, A.M. & Ruiter, P.C. de | C & N mineralisation in sandy and loam grassland soils: the role of microbes and microfauna | 1994 | Mineralisation; Soil Organic Carbon; Soil Microorganisms | Journal | Soil Biol. Biochem.; 26 (11); 1565-1571 | English | Hardcopy:Partial | Field expt. to investigate the relationship between mineralisation and microbial biomass | Differences in C mineralisation rates between the 4 grasslands could .. be explained by the differences in bacterial biomass. .. [but] did not correspond with the differences in N mineralisation.; .. the observed C & N mineralisation rates could .. be calculated using different bacterial C/N ratios .. (8 for the sandy soils, 4.5 and 6 for the loams).; .. the contribution of the fauna to C mineralisation was small. .. The direct contribution of the fauna to N mineralisation ranged from 7.3% to 28.0%.; .. the continuous high input of decaying root and leaf material in grassland soils .. seems not to lead to a high biomass but to a high [microbial] activity.; The fraction of fungi in the microbial biomass .. was very small in all soils. |
| 1248 | Hassink, J., Oude Voshaar, J.H., Nuhuis, E.H. & Veen, J.A. van | Dynamics of the microbial populations of a reclaimed-polder soil under a conventional and a reduced-input farming system | 1991 | Organic Farming; Soil Microorganisms | Journal | Soil Biol. Biochem.; 23 (6); 515-524 | English | Hardcopy:Partial | Expt. to compare the microbial populations of two fields, one under conventional farming and the other under reduced inputs | Characteristics of populations changed considerably in time. These changes were larger than differences between the two fields.; .. the size of the microbial biomass was larger on the reduced-input field. |
| 616 | Hassink, J., Whitmore, A.P. & Kubát, J. | Size and density fractionation of soil organic matter and the physical capacity of soils to protect organic matter | 1997 | Soil Organic Carbon | Journal | Eur. J. Agron.; 7 (1-3); 189-199 | English | Hardcopy:Partial; PDF:Full | Study of grassland and arable soils to investigate the idea that the protection of SOM depends both on soil texture and on the degree to which the protective capacity of the soil is already occupied. | Light and intermediate fractions of the macro-OM (> 150 m) respond much faster to changes in C input than smaller size fractions .. [so they] can be used as early indicators of effects of soil management on changes in SOM.; The amount of C in macro-OM is controlled by soil management, while the amount of C protected by clay and silt particles is controlled mainly by soil texture. |
| 137 | Hatley, D.L.J., Garwood, T.W.D. & Johnson, P.A. | The impact of changing farming practices on soil organic matter and soil structural stability of fen silt soils | 2001 | Soil Organic Carbon; Tillage | Book | Rees, R.M., Ball, B.C., Campbell, C.D. & Watson, C.A. (eds.); Sustainable Management of Soil Organic Matter; | English | Hardcopy:Partial; Wordperfect:Full | Field expt. to study the trends in organic matter content in arable soils | At three of the long-term arable sites, SOM levels declined by 0.5-1.7% over the monitoring period. .. At the six ley-arable sites and two of the arable sites there were no changes in SOM levels .. The data presented here suggest that all sites will reach stable or very slowly changing OM levels under continuous arable cropping regimes. It is concluded .. that modern farming systems are not causing a decline in the OM content of fen silt soils. |
| 270 | Hatton, T.J. & Nulsen, R.A. | Towards achieving functional ecosystem mimicry with respect to water cycling in southern Australian agriculture | 1999 | Sustainability | Journal | Agrofor. Syst.; 45 (1-3); 203-214 | English | Hardcopy:Partial | Review of the possibility of improving soil water balance by imitating natural ecosystems | Replacement of these [natural] ecosystems with conventional agriculture has resulted in large-scale disruption of the natural water cycle .. effective water balance control will be achieved only at a leaf area index approaching that of the natural state .. |
| 519 | Haugen-Kozyra, K., Juma, N.G. & Nyborg, M. | Nitrogen partitioning and cycling in barley-soil systems under conventional and zero tillage in central Alberta | 1993 | Mineralisation; Soil N Dynamics; Tillage | Journal | Can. J. Soil Sci.; 73 (2); 183-196 | English | Hardcopy:Partial | Expt. to measure the distribution of N between shoots, roots, microorganisms, soil organic and soil mineral N. At any one time about 98% of the N in the system is in the SOM, about 1% in the crop shoot, only about 0.1% in the roots, nearly 1% in the microbial biomass and a mineralised portion starting at just over 1% and falling to about 0.1% as the crop matures. | In the sort run the mineralisation-immobilisation turnover of N slows under ZT `and OM accumulates.; .. more 15N .. was converted to organic N under ZT than CT, thus ZT systems have the potential of conserving N. |
| 1041 | Hauggaard-Nielsen, H., Neergaard, A. de, Jensen, L.S., Høgh-Jensen, H. & Magid,J. | A field study of nitrogen dynamics and spring barley growth as affected by the quality of incorporated residues from white clover and ryegrass | 1998 | Green Manure; Soil N Dynamics | Journal | Plant Soil; 203; 91-101 | English | Hardcopy:Partial; PDF:Full | Field expt. to study the effect of incorporated green manures on the following crop | Incorporated residue N was highest in the [fertilised] white clover in pure stand & lowest in the [fertilised] ryegrass in pure stand treatments, ..; The highest crop dry matter production & N uptake was measured in the [fertilised clover pure stand] treatment, followed by the [unfertilised mixed ryegrass/ clover] and the fallow treatments .. |
| 982 | Haumaier, L. & Zech, W. | Black carbon - possible source of highly aromatic components of soil humic acids | 1995 | Soil Organic Carbon | Journal | Org. Geochem.; 23 (3); 191-196 | English | Hardcopy:Partial; PDF:Full | Review of evidence as to the black C origin of humic substances in soil. The non -phenolic substances found in some humic materials may be the final degradation products of non-phenolic parts of lignin or may come from carbonised materials produced in vegetation fires. | .. black C is considered to be a possible source of the chemically most stable aromatic soil C pool.; Soil humic substances .. are considered to be formed during the decay of plant and microbial residues, either by selective preservation and transformation of constituents resistant to biodegradation, e.g. lignin .. and aliphatic polymers, or by condensation of low-molecularweight degradation products such as phenols, .. sugars and amino-acids. |
| 1591 | Hawthorne, J. | Energy usage in food processing and distribution | 1975 | Energy in Agriculture | Journal | Span; 18 (1); 15-16 | English | Hardcopy:Full | The energy used in the transport and processing of crops into food is estimated. The transport and processing of crops into food consumes three times as much energy as the actual production of the crops. Tables of energy inputs into food processing and transport are given. | The financial accountant .. is concerned with a dual demonstration. In the balance sheet he shows the asset position .. the wealth of the company at a fixed point in time. In the profit-&-loss account he takes change with time into account & demonstrates the overall result of a large number of interrelated transactions at the end of a fixed period of time. The cost accountant .. analyses the day-to-day operations of the company in order to discover which of these is effective and which is wasteful. .. Energy accountancy of both sorts is needed. |
| 1387 | Hayes, M.H.B. & Clapp, C.E. | Humic substances: considerations of compositions, aspects of structure and environmental influences | 2001 | Soil Organic Carbon | Journal | Soil Sci.; 166 (11); 723-737 | English | Hardcopy:Partial | A general review of the study of humic substances, including the definition of the term, isolation of the substances and C sequestration | SOC reserves (estimated to be ca. 1500 Pg) are almost three times those in all living matter on earth. .. the C emissions from the soil (arising from microbial transformations of SOM) are considered to be about 60 Pg. [= historical emissions from agriculture ??], which is about ten times more than the emissions from fossil fuels. .. Estimates of the total C sequestration potential through improved management of U.S. cropland have been placed at 75 to 208 Tg .. and this is thought to be possible through land conservation .., intensification of prime agricultural land (which would involve conservation tillage and residue management), irrigation water management and improved cropping systems.; Humic substances are the major components of .. SOM and .. are by far the most abundant organic materials in the environment .. [they are] complicated mixtures of biologically transformed organic debris.; They result from the decomposition of plant and animal residues.; Humic substances are a category of naturally occurring biogenic, heterogeneous organic substances that can generally be characterised as being yellow-to-black in colour, of high molecular weight and refractory. .. However, there is no longer universal acceptance that HS are of high molecular weight.; Humic acids are precipitated at .. pH1 ..; fulvic acids remain in solution at all pH values; and humin materials are not soluble in aqueous acid or base.; .. it would be wrong to attribute to HS all of the C sequestered by SOM. For example, glomalin, a glycoprotein in the hyphae of AM fungi was found at levels of more than 60 mg/cc in tropical soils. .. glomalin content can be correlated with aggregate stability .. it is sorbed to the soil colloidal surfaces, which would explain its resistance to decomposition .. [it] takes several years to decades to turn over in the soil; . |
| 1249 | Haynes, R.J. | Labile organic matter as an indicator of organic matter quality in arable and pastoral soils in New Zealand | 2000 | Soil Organic Carbon | Journal | Soil Biol. Biochem.; 32 (2); 211-219 | English | Hardcopy:Partial; Wordperfect:Full | Expt. to test the labile OM content of arable and pastoral soils as an indicator of the OM quality | .. the labile SOM fractions measured (light fraction C, microbial biomass C and water-soluble C) were significantly correlated with organic C content.; Labile OM was more closely correlated with previous cropping history .. than with SOC content.; .. the three measures of labile OM used were closely correlated with one another .. The light fraction represents a transitory pool between fresh residues and humified stable OM. It acts as a reservoir of relatively labile C which supplies the soluble C pool. A large portion of the microbial community is associated with the light fraction and soil respiration rates are often correlated with the light fraction C content. Water-soluble C is the primary energy source for the microbial biomass although, in turn, microbial metabolites (e.g. polysaccharide mucilage) contribute significantly to the soluble C pool. .. it is [also] a primary source of mineralisable N, P and S and it influences the availability of metal ions in soils by forming soluble complexes. |
| 1250 | Haynes, R.J. & Beare, M.H. | Influence of six crop species on aggregate stability and some labile organic matter fractions | 1997 | Green Manure; Roots & Rhizodeposition; Soil (General) | Journal | Soil Biol. Biochem.; 29 (11/12); 1647-1653 | English | Hardcopy:Full; PDF:Full | Lab. expt. to compare the effect on the soil structure of various cereals, grasses and legumes | For the non-legumes in our study, increases in root mass and length density, microbial biomass C, cold and hot water-extractable carbohydrate content and aggregate stability followed the order: barley = wheat < prairie grass < Italian ryegrass.; In comparison with the non-legumes, growth of white clover and lupin resulted in an unexpectedly high aggregate stability and to a lesser extent microbial biomass C content relative to their rather small root mass and length. Lupin, for example, had the highest aggregate stability of all the crops, while white clover had an aggregate stability similar to that of Italian ryegrass..; the higher N content of rhizodeposited organic material .. from the legumes is likely to have been a major difference leading to a larger.. microbial popul'n. |
| 952 | Haynes, R.J. & Naidu, R. | Influence of lime, fertiliser and manure applications on soil organic matter content and soil physical conditions: a review | 1998 | Soil (General) | Journal | Nutr. Cycl. Agroecosyst.; 51; 123-137 | English | Hardcopy:Partial; PDF:Full | Review of the effects on soil properties of lime, chemical fertiliser and animal manure applications | .. liming can result in dispersion of clay colloids & formation of surface crusts. .. both lime & hydroxy-Al polymers formed by pptn of exchangeable Al, can act as cementing agents bonding soil particles together and improving soil structure.; For fertiliser additions short-term effects appear to be relatively rare. Their main effect is a long-term one through an increase in crop production with an attendant increase in SOM content and soil biological activity. For organic manures the major effect is simply the addition of OM to the soil. |
| 1547 | Haynes, R.J., Swift, R.S., Stephen, R.C. | Influence of mixed cropping rotations (pasture-arable) on OM content, waterstable aggregation and clod porosity in a group of soils | 1991 | Soil (General) | Journal | Soil Tillage Res.; 19; 77-87 | English | Hardcopy:Partial | Field study to investigate dependency of the OM content and aggregation of soils on crop rotations | .. the total SOM content remained relatively unchanged, yet microbial biomass C, hot-water-extractable carbohydrate and aggregate stability increased markedly during the pasture phase and declined during the arable period. .. increase in aggregate stability during the short-term pasture is due principally to production of binding carbohydrates .. by the large microbial biomass .. |
| 1114 | Heath, J., Ayres, E., Possell, M., Bardgett, R.D., Black, H.I.J., Grant, H., Ineson, P. & Kerstiens, G. | Rising atmospheric CO2 reduces sequestration of root-derived soil carbon | 2005 | Roots & Rhizodeposition; Soil Organic Carbon | Journal | Science; 309; 1711-1713 | English | Hardcopy:Partial; Wordperfect:Full | Field expt. to quantify the sequestration of root-derived SOC benerath trees | In temperate and boreal forests the amount of C stored in the soil is about four times as high as that stored in the vegetation and 33% higher than total C storage in tropical forests.; Despite enhanced tree growth, we found a marked decline in sequestration of root-derived C in the soil as CO2 concentration increased ..; The reduced sequestration of root-derived C in the soil under `elevated CO2 was associated with an increase in soil microbial respiration ..; (; .. although soil microbial respiration increased under elevated CO2, the effect of this on the decomposition of native soil C is not known. |
| 984 | Hedges, J.I. & Oades, J.M. | Comparative organic geochemistries of soils and marine sediments | 1997 | Soil Organic Carbon | Journal | Org. Geochem.; 27 (7/8); 319-361 | English | Hardcopy:Full; PDF:Full | Review of research into the composition and dynamics of organic matter in soils and marine sediments | Vascular plants predominate on land, where soils are deeply leached by percolating water & receive OM from falling debris & penetrating roots. The large size of vascular plants & their high conc'ns of carbon-rich bio-macromolecules such as cellulose, lignin & tannin, necessitate recycling by aggressive consortia of microorganisms, including fungi armed with O2-requiring oxidative enzymes. .. plant products are degraded extensively by microorganisms, leaving small organic remnants which are soluble in base and depleted in conventionally measurable biochemicals. Much of the surviving OM is intimately associated with mineral surfaces and enclosed within particle aggregates, and thus may be physically protected from microbial attack. Degradation under oxic conditions is severe .. As a result, even physically protected OM can slowly be mineralised, along with intrinsically resistant substrates such as lignin, pollen, kerogen and coal. |
| 713 | Hedges, J.I., Blanchette, R., Weliky, K. & Devol, A. | Effects of fungal degradation on the CuO oxidation products of lignin: a controlled laboratory study | 1988 | Lignin and CBW | Journal | Geochim. Cosmochim. Ac. ; 52 (11); 2717-2726 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the oxidation products of lignin that has been degraded for varying periods of time by white- and brown-rot fungi | Upon CuO oxid'n most fresh vascular plant tissues yield ratios of vanillic acid to vanillin (Ad/Al)v & syringic acid to syringaldehyde (Ad/Al)s that lie in the range of 0.1-0.2, whereas increasingly elevated ratios are obtained from .. .., lignin structural units in humus and humic & fulvic acids.; .. white-rot fungi are obligate aerobes & do not degrade waterlogged wood efficiently. |
| 983 | Hedges, J.I., Eglinton, G., Hatcher, P.G., Kirchman, D.L., Arnosti, C., Derenne, S., Evershed, R.P., Kögel-Knaber, I., de Leeuw, J.W, Littke, R., Michaelis, W. & Rullkötter, J. | The molecularly uncharacterised component of non-living organic matter in natural environments: a review | 2000 | Soil Organic Carbon | Journal | Org. Geochem.; 31 (10); 945-958 | English | Hardcopy:Partial; PDF:Full | Review of the current state of knowledge of the chemical compos'n of SOM | OM is a thermodynamic anomaly atop a free energy precipice that drops off on all sides to dispersed stable ingredients such as carbon dioxide, water, nitrate & phosphate. Given the high free energy yield when electrons are passed from OM to molecular oxygen,nitrate, transition metal ions & sulphate, it is little surprise that only one or two carbons out of one thousand in org. molecules ultimately escape oxidation to be preserved in marine sediments.; In spite of over half a century of effort & rapidly increasing analytical sophistication, more than half of all the OM in soils ..still remains uncharacterised at the molecular level. |
| 787 | Heeger, R. & Brom, F.W.A. | Intrinsic value and direct duties: from animal ethics towards environmental ethics? | 2001 | Agricultural Ethics | Journal | J. Agric. Environ. Ethics; 14 (2); 241-252 | English | Hardcopy:Partial; PDF:Full | The question of our moral duty towards other living beings is discussed. Does this duty only concern beings that are aware or sentient? And does it differ towards different beings - for example, towards animals and plants and towards collective entities like populations, species and ecosystems? | |
| 900 | Heijden, M.G.A. van, Kilronomos, J.N., Ursic, M., Moutoglis, P., StreitwolfEngel, R., Boller, T., Wiemken, A. & Sanders, I.R. | Mycorrhizal fungal diversity determines plant biodiversity, ecosystem variability and productivity | 1998 | Agricultural Ecology; Soil Microorganisms | Journal | Nature (Lond.); 396; 69-72 | English | Hardcopy:Full | Expt. to demonstrate the importance of arbuscular mycorrhizal fungi in ecosystems | .. belowground diversity of arbuscular mycorrhizal fungi is a major factor contributing to the maintenance of plant biodiversity and to ecosystem functioning.; AMF are abundant in soils of most ecosystems [and] form .. symbiotic associations with the roots of ca. 80% of all terrestrial plants species, thereby acting as extensions of plant root systems and increasing the nutrient uptake, especially of phosphorus.; .. the species competition and diversity of AMF communities have the potential to determine plant biodiversity in natural ecosystems.; Both the plant diversity .. and productivity above- and belowground increased with increasing AMF species richness.; Increasing plant diversity has been shown to lead to greater ecosystem productivity. |
| 650 | Heim, A. & Schmidt, M.W.I. | Lignin turnover in arable soil and grassland analysed with two different labelling approaches | 2007 | Lignin and CBW; Soil Organic Carbon | Journal | Eur. J. Soil Sci.; 58; 599-608 | English | Hardcopy:Partial; PDF:Full | Field expt. to measure the rate of turnover of lignin in soil | Results indicate faster apparent turnover for lignin (5-26 years in grassland, 9-38 years in arable soil) compared with bulk SOC (20-26 years in grassland, 51 years in arable soil). Although these calculated lignin turnover times cannot be extrapolated to the whole soil profiles, this paper provides isotopic evidence that lignin in soils is not preferentially preserved .. a considerable prop'n of lignin in temperate soils canbe stabilised for atleast a few decades. |
| 985 | Heim, A. & Schmidt, M.W.I. | Lignin is preserved in the fine silt fraction of an arable Luvisol | 2007 | Lignin and CBW; Soil Organic Carbon | Journal | Org. Geochem.; 38; 2001-2011 | English | Hardcopy:Partial; PDF:Full | Field expt. to trace the fate of lignin in soil | A kinetic model suggests the existence of a fast and a slow decomposing lignin pool in the soil..; [the fraction of lignin reaching the faster pool] is calculated to be 94.9%.; Although .. the slower pool receives only about 5% of the input, it is about 5.6 times larger than the fast pool..; .. stabilisation of lignin biomarkers in soil is not due to their inherent chemical recalcitrance but depends on interaction with mineral matter... a large part of the lignin input to soil never reaches this stable fraction, but turns over more rapidly.; old .. lignin .. had accumulated mainly in the silt (2-20 %m) fraction. |
| 891 | Heinrich, C. | 70 Jahre viehlose Wirtschaft | 1957 | Stockless Farming | Journal | Mitteilungen der Deutschen Landwirtschafts-Gesellschaft; 10.01.1957; | German | Hardcopy:Partial | Two non-organic stockless holdings are described, both near Worms in the Rhine valley: Hof Mundorf, Pfiffligheim (stockless since 1888, apart from two cows and 3 pigs for their own use) and MGckenhuserhof, RheindGrkheim ('stockless' since 1910, apart from 6 cows, 20 pigs, 6 draught horses and 2 draught oxen). On both holdings the lack of animals allows greater care to be taken of the arable land. They use very little chemical fertiliser and little green manure, but their yields are comparable with the neighbouring conventional farmers. The author refers to an earlier article of his (in the August 1949 issue of the same journal), in which he states that 'die Viehhaltung auf 40, ja sogar 30 GV [Grossvieh ??] je 100 ha im sGdlichen Niedersachsengebiet eingeschraenkt werden koenne.' The figures for Hof Mundorf and the MGckenhuserhof are 6 and 7 GV per ha respectively, not including the draught animals. | |
| 736 | Helfrich, M., Ludwig, B., Buurman, P. & Flessa, H. | Effect of land use on the composition of soil organic matter in density and aggregate fractions as revealed by solid-state 13C NMR spectroscopy | 2006 | Soil Organic Carbon | Journal | Geoderma; 136; 331-341 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the differences in the chemistry of OM in soils from different land uses | The forest litter had the largest content of aromatic & alkyl-C... The SOM of the .. forest soil consisted mainly of POM with a high content of spruce litterderived alkyl-C. The SOC stocks in the grassland and maize soil were dominated by mineral-associated SOM, which contained relatively larger proportions of aryl & carbonyl-C. The decrease of the SOC conc'n induced by cultivation resulted in a relative accumulation of aromatic C structures in the mineral-bound SOM. In all soils the free POM had a smaller proportion of alkyl-C & a larger proportion of O-alkyl-C than the POM occluded in aggregates. The mean age of the SOM in the density fractions of the maize soil increased with increasing aromaticity in the order: free POM < occluded POM < mineral-associated OM. |
| 184 | Heller, M.C. & Keoleian, G.A. | Assessing the sustainability of the US food system: a life-cycle perspective | 2003 | Sustainability | Journal | Agric. Sys.; 76, 3; | English | Hardcopy:Partial | The sustainability of the human food cycle is discussed, taking into consideration issues of food consumption as well as food production. Factors threatening the sustainability of the food cycle are reviewed. | .. a widely accepted pragmatic definition of sustainable agriculture does not exist. .. there tends to be agreement that an appraisal of sustainability should integrate economic, social and environmental dimensions.; The long-term future of agricultural production .. cannot be assessed without consideration of the consumption patterns and processes that drive production. |
| 383 | Hellmann, B., Zelles, L., Palojärvi, A. & Bai, Q. | Emission of climate-relevant trace gases and succession of microbial communities during open-windrow composting | 1997 | Compost & Biocontrol; Greenhouse Gases | Journal | Appl. Environ. Microbiol.; 63 (3); 1011-1018 | English | Hardcopy:Partial; PDF:Full | Review of the composting process, the stages through which it passes and the gases evolved during them | @; The emission rates of CO2, CH4 and N2O increased successively during compost maturation: initially in the presence of easily degradable nutrients, during high temp, & after the temp had cooled down respectively.; .. we can characterise the maturation p |
| 1548 | Hendrix, P.F., Han, C.R. & Groffman, P.M. | Soil respiration in conventional and no-tillage agroecosystems under different winter cover crop rotations | 1988 | Cover Crops; Greenhouse Gases; Tillage | Journal | Soil Tillage Res.; 12 (2); 135-148 | English | Hardcopy:Partial | Expt. to study the CO2 emission from soils under conventional and zero tillage | x; Overall CO2 output was significantly higher from NT than from CT soils and from soils cropped to clover than from those cropped to rye.; Ploughing did not stimulate CO2 production in CT as was expected, but annual CO2 production in these systems may have been underestimated. Tillage appeared to affect the timing rather than the total amount of CO2 production. |
| 1726 | Henn, M.R. & Chapela, I.H. | Differential C Isotope Discrimination by Fungi during Decomposition of C3- and C4-Derived Sucrose | 2000 | Uncategorised | Journal | Appl. Environ. Microbiol.; 66 (10); 4180-4186 | English | PDF:Full | ||
| 1252 | Henriksen, T.M. & Breland, T.A. | Evaluation of criteria for describing crop residue degradability in a model of carbon and nitrogen turnover in soil | 1999 | Green Manure; Soil Organic Carbon; Soil N Dynamics | Journal | Soil Biol. Biochem.; 31; 1135-1149 | English | Hardcopy:Partial; PDF:Full | Modelling the decompos'n of plant residues, based on the incubation in soil of various plant residues, ranging from OSR haulm to white clover | .. cpds found in the cell cytoplasm (e.g. simple carbohydrates, nucleic acids, amino acids, proteins) are grouped together in a metabolic pool, while cell-wall components (cellulose, hemicellulose, lignin) constitute a structural pool.; On d 100 .. only 7.8% of the initial cellulose content was recovered in the herbage residues, while 26% still remained in the barley straw residues.; .. rapidly growing DPM-decomposers with a low C/N ratio (4.0) initially dominate the microbial biomass, whereas SPM-decomposers (C/N = 6.0) take over when DPM becomes depleted. .. [F/B] biomass and activity successively increases during residue decompos'n .. the C/N ratio of bacteria tends to be lower than that of fungi. |
| 459 | Henriksen, T.M., & Breland, T.A. | Carbon mineralisation, fungal and bacterial growth and enzyme activities as affected by contact between crop residues and soil | 2002 | Mineralisation; Mulch; Soil Microorganisms | Journal | Biol. Fertil. Soils; 35; 41-48 | English | Hardcopy:Full; PDF:Full | Lab. expt. to study the effect of soil-residue contact on the decomposition of plant structural residues in two soils of differing texture | For clover material poor soil contact increased cumulative C mineralisation by 5% of initial C in the loamy topsoil but had no effect in the silty subsoil. For the more slowly degradable cellulose- and hemicellulose-rich straw, on the other hand, poor soil contact reduced C mineralisation by 6% of initial C.; .. a delayed colonisation or growth of microbes capable of producing extracellular cellulases and hemicellulases is a major reason for reduced straw decomposition under conditions where residue-soil contact is poor.; The positive effect [of poor soil contact on mineralisation of clover residues] may be explained by a reduced volume of detritusphere soil, which by various mechanisms retains a significant fraction of decomposing C from herbaceous crop residues. |
| 1251 | Henriksen, T.M., Breland, T.A. | Nitrogen availability effects on carbon mineralisation, fungal and bacterial growth and enzyme activities during decomposition of wheat straw in soil | 1999 | Mineralisation; Soil Microorganisms; Soil N Dynamics | Journal | Soil Biol. Biochem.; 31; 1121-1134 | English | Hardcopy:Partial; PDF:Full | 70-day expt. to study the decomposition in soil of mature wheat straw, which showed that wheat straw mineralisation may be retarded at N conc'ns well above those frequently found after grain harvest. | N addition often stimulates C mineralis'n from accessible plant constituents, such as non-lignified cellulose, whereas decompos'n of lignin & lignified material is slowed down.; The N requirement for opt. decompos'n has been considered to be about 1.2-1.7% of plant dry matter.; Literature values for the humification coefficient (aH) range from 0.2 to 0.7 and apparently depend on the soil clay content.; The negative N effect on C mineralisation towards the end may .. be due to a negative effect on lignin degrad'n, resulting in reduced availability of the structural carbohydrates in the lignocellulose complex. The latter explanation is supported by the negative effect of N addition on C mineralis'n .. in unamended soil, where humus and, consequently, lignin-like substances were the dominating substrates.; Rapidly proliferating bacteria play an important part during the initial attack on easily decomposable substances, while fungi are the major decomposers of the N-deficient structural straw material. |
| 589 | Hetherington, R. | An input-output analysis of carbon dioxide emissions for the UK | 1996 | Energy Resources; Greenhouse Gases; Sustainability | Journal | Energy Convers. Manage.; 37 (6/8); 979-984 | English | Hardcopy:Full | A table of all industrial products in the U.K. is presented, giving the CO2 intensity of their production, expressed in gm. CO2 per of output. Electricity xproduction is by far the most CO2 intensive, followed by cement, then by ceramics, iron and steel and air transport. | .. an individual's direct consumption of fossil fuels causes CO2 release, which [is] relatively easy to identify and quantify. However, any activity that requires fossil fuel consumption also has an associated release of CO2. This `constitutes the indirect CO2 emissions, which are more difficult to identify and (quantify.; .. current CO2 release will only change if production becomes more efficient. For the U.K. as a whole, energy efficiency increased by less than 5% between 1984 and 1992 .. |
| 760 | Hicke, J.A., Asner, G.P., Randerson, J.T., Tucker, C., Los, S., Birdsey, R., Jenkins, J.C. & Field, C. | Trends in North American net primary productivity derived from satellite observations, 1982-1998 | 2002 | Greenhouse Gases | Journal | Global Biogeochem. Cy.; 16; | English | Hardcopy:Partial | xCO2 enrichment of the atmosphere cannot account for the large increase in NPP during the period studied. Other factors that may have been responsible are better and more intensive agricultural practices, use of GM crops, regrowth of forest on abandoned arable land and increases in summer temperature and precipitation. | NPP increases of 30% or more occurred across the continent from 1982 to 1998. (During this period the atmosphere's CO2 concentration rose by 25.74 ppm. .. for herbaceous crop plants, which display NPP increases of 30% in response to a [standard] 300 ppm increase in atmospheric CO2 enrichment, [the 25.74 ppm increase] would have been expected to increase crop productivity by .. 2.6%. Similarly, for trees, which display NPP increases of 80% in response to a [standard] 300 ppm increase in atmospheric CO2, the expected increase in [NPP] .. would be .. 6.9%. |
| 1115 | Hirst, E. | Food-related energy requirements | 1974 | Energy in Agriculture | Journal | Science; 184; 137 | English | Hardcopy:Partial | Energy use in food production is estimated and compared over time and between different food types. Energy use is much lower in the case of crops than for meat and dairy products. It has increased substantially over time. | The increase in per capita food-related energy [from 1960 to 1970] was due primarily to increased energy use for refrigerators, stoves, freezers and automobiles. Changes in eating habits also contributed ..; American farming achieves such high labour productivity by substituting fuels for labour .. |
| 816 | Hobbs, P.R. | Tillage and crop establishment in South Asian rice-wheat systems: present practices and future options | 2001 | Miscellaneous; Tillage | Journal | Journal of Crop Production; 4 (1); 1-22 | English | Hardcopy:Partial | Review of techniques being introduced in the Indo-Gangetic Plain to improve the yields and reduce production costs in rice-wheat rotations | ... wet ploughing (locally called puddling) is most commonly used to prepare the field for eventual transplanting of rice seedlings. The field is usually ploughed dry, flooded and then puddled (ploughed when flooded) to create a soil with poor soil physical properties and low water infiltration.; For wheat, the following systems are described ...: 1. surface seeding .. no land preparation is used and seed are merely broadcast onto saturated soils. 2. zero-tillage .. wheat is planted directly into the rice stubble without land preparation ... 3. reduced-tillage systems .. a rotovator is used to prepare the soil ahead of a seed drill and compaction mechanism. This allows wheat to be planted at the same time as land is tilled. 4. bed planting systems. |
| 1683 | Hobbs, P.R. | Zero tillage: averting dry wells and depleted soils in South Asia | 2001 | Tillage | Website | www.cimmyt.cgiar.org/whatiscimmyt/ar00_2001/asia/zerotillage | English | Hardcopy:Full | A brief review of South Asia's agricultural problems and how zero tillage can help to overcome them. The main problems are water scarcity and declining soil quality, due to over-intensive cultivation, lack of fallow and failure to replenish SOM. Farmer-driven research into the direct sowing of wheat into rice stubble or even into the preceding rice crop is helping to overcome these problems. Growing crops on permanent raised beds is also being tested. The area of the Indo-Gangetic Plain estimated to be under zero tillage in the 2001-2 season was 300,000 ha, compared with a total area of rice-wheat cultivation of 12 million ha. | Water savings under [raised-]bed planting are even more dramatic than those for zero tillage alone.; Rather than spend long years 'cooking' technologies on expt.[al] stations, the RWC [Rice-Wheat Consortium] and its partners have given farmers promising technologies to test under their conditions. |
| 1003 | Hobbs, P.R. & Gupta, R.K. | Rice-wheat cropping systems in the Indo-Gangetic plains: issues of water productivity in relation to new .. | 2001 | Tillage | Website | Paper presented to the Water Productivity Workshop at IWMI, Colombo, Sri Lanka, 15-16.11.2001 | English | Hardcopy:Partial | [title contd.: resource-conserving technologies] Various resource conserving technologies applicable to rice-wheat cultivation are described, including surface seeding and zero tillage with inverted-T openers. | This [surface seeding] is a traditional farmer practice .. in parts of Eastern India and Bangladesh. Wheat seed is either broadcast before the rice crop is harvested (relay planted) or after harvest. .. The key to success .. is having the correct soil moisture at seeding. Too little moisture results in poor germination and too much moisture can cause the seed to rot. A saturated soil is best. .. In China .. farmers apply cut straw to mulch the soil, reduce evaporative losses and control weeds. The standing stubble also protects the young seedlings from birds. |
| 692 | Hocking, P.J., Kirkegaard, J.A., Angus, J.F., Gibson, A.H. & Koetz, E.A. | Comparison of canola, Indian mustard and Linola in 2 contrasting environments I. Effects of nitrogen fertiliser on dry-matter production, seed yield & seed quality | 1997 | Rape and Biodiesel; Soil N Dynamics | Journal | Field Crops Res.; 49 (2-3); 107-125 | English | Hardcopy:Partial; PDF:Full | Field expt. to compare the N-fertiliser response of three oilseed crops | Based on the overall growth and grain yield responses to N fertiliser and on N removal in grain, it is suggested that about 25% more N be applied to canola than to wheat, that Indian mustard receive about the same N fertiliser rate as wheat and that Linola requires about 20% less N than wheat.; The decrease in oil percentage of the oilseeds with increasing N supply reflects the inverse relationships between oil concentration and seed protein content ..; .. there was only a 2% oil decrease accompanying the 1.3 t ha-1 grain yield response to N for canola at Dirnaseer in 1992. Clearly, in this case, oil yield ha-1 increased despite the reduction in oil concentration. |
| 1044 | Hoffland, E. | Quantitative evaluation of the role of organic acid exudation in the mobilisation of rock phosphate by rape | 1992 | Phosphorus Cycling | Journal | Plant Soil; 140; 279-289 | English | Hardcopy:Partial | Modelling the effect of acid exudation rates on phosphate uptake from rock phosphate | Phosphorus-deficient rape plants appear to acidify .. their rhizosphere by exuding malic and citric acid.; The exudation rates measured are far more than adequate to explain the relatively large phosphate uptake from rock P by rape. |
| 384 | Hofrichter, M., Lundell, T. & Hatakka, A. | Conversion of milled pine wood by manganese peroxidase from Phlebia radiata | 2001 | Lignin and CBW | Journal | Appl. Environ. Microbiol.; 67 (10); 4588-4593 | English | Hardcopy:Partial; PDF:Full | Lab. expt. to study the action of purified manganese peroxidase on pine wood | The enzymatic attack resulted in the polymerisation of lower-molecular-mass soluble wood components and in the partial depolymerisation of the insoluble bulk of pine wood ..; ..the disintegration of non-extracted solid lignocellulose (MPW) was accompanied in our present study .. by substantial formation of high-molecular-mass water-soluble fragments resulting from the obvious polymerisation of low-molecular-mass wood components. |
| 385 | Hofrichter, M., Vares, T., Kalsi, M., Galkin, S., Scheibner, K., Fritsche, W. & Hatakka, A. | Production of Mn peroxidase and organic acids and mineralisation of 14C-labelled Xlignin (14C-DHP) during solid-state fermentation of wheat straw with the white-rot fungus Nematoloma frowardii | 1999 | Lignin and CBW; Mineralisation | Journal | Appl. Environ. Microbiol.; 65 (5); 1864-1870 | English | Hardcopy:Partial | Expt. to study the enzymatic degradation of lignin using synthetic 14C-ring-labelled lignin. 58-75% of the label was found in the CO2 and only 3-13% in the fungal biomass and residual straw. | Except for cellulose lignin is the most abundant biological compound found in nature, yet it is degrade by only a small number of microorganisms, primarily basidiomycetes (white rot fungi) .. [which] produce a variety of extracellular enzymes that are though to be involved in lignin degradation, the best characterised of which are laccase, lignin peroxidase and manganese peroxidase (MnP).; In many fungi MnP is though to play the crucial role in the primary H attack on lignin, because it generates the strong oxidant Mn3+.; Dicarboxylic or O-hydroxycarboxylic acids are required for MnP activity .. oxalic acid has been found to be the main organic acid produced ..; Lignocellulose contains high levels of Mn, which, after Ca, K and Mg, is the most abundant metal.; Effective mineralisation and solubilisation of lignin by white rot fungi have 0been demonstrated by using both natural and synthetic 14C-labelled lignins and lignocelluloses. |
| 327 | Hoitink, H.A.J. & Boehm, M.J. | Biocontrol within the context of soil microbial communities: a substrate-dependent phenomenon | 1999 | Compost & Biocontrol; Miscellaneous; Soil Microorganisms | Journal | Annu. Rev. Phytopathol.; 37; 427-446 | English | Hardcopy:Full; PDF:Full | Review of current knowledge of biological control agents | Biocontrol agents require edaphic sources of OM for sustained activity against Pythium and Phytophthora root rots. .. the quality and quantity of the OM are critical to survival and efficacy of bacterial biocontrol agents such as Pseudomonas & Pantoea spp. Rhizosphere deposition products and root exudates clearly do not provide adequate quantities of slow-release sources of bioavailable energy to introduced bacterial biocontrol agents.; Org. amendments such as green manures, stable manures and composts can provide this food base and have long been recognised to facilitate biological control if applied well ahead of planting. |
| 10 | Hoitink, H.A.J., Stone, A.G. & Grebus, M.E. | Suppression of plant diseases by composts | 1996 | Compost & Biocontrol | Book | Bertoldi, M. de, Sequi, P., Lemmes, B., & Papi, T. (eds.); The science of composting; | English | Hardcopy:Partial; Wordperfect:Full | Review of the mechanisms of suppression of plant diseases by compost | Heat exposure during composting kills or inactivates pathogens if the process is monitored properly. Biocontrol agents with the exception of Bacillus spp. also are killed by this heat treatment, however. Thus, biocontrol agents largely must re-colonise composts after peak heating.; The moisture content of compost critically affects the potential for bacterial mesophiles to colonise the substrate after peak heating. Dry composts (<34% moisture w/w) become colonised by fungi and are conducive to Pythium diseases. The moisture content must be high enough (at least 40-50% w/w), so that bacteria can colonise the substrate after peak heating and induce biological control. |
| 405 | Holford, I.C.R. | Comments on intensity-quantity aspects of soil phosphorus | 1991 | Phosphorus Cycling | Journal | Aust. J. Soil Res.; 29 (1); 11-14 | English | Hardcopy:Partial | n/a | .. there are 3 major determinants of available P in soil (i) the concentration or intensity of P in the soil solution; (ii) the quantity of P in the solid phase that will equilibrate with the solution during the life of the plant; and (iii) the buffering capacity, which expresses the dynamic relationship between the solid and solution phases. |
| 406 | Holford, I.C.R. | Soil phosphorus: its measurement and its uptake by plants | 1997 | Phosphorus Cycling | Journal | Aust. J. Soil Res.; 35; 227-239 | English | Hardcopy:Partial | Review of knowledge of availability of soil P and P uptake by crops | The buffering capacity is the ability of the soil solution to resist a change in its P concentration as P is removed by plant uptake or added in fertilisers or organic materials. .. [it is] controlling the relationship between the solid phase P and its concentration in solution. The solid phase P involved in this relationship is only a small proportion of the total P and is known as labile P. It is usually measured by isotopic exchange, but this exchangeable P component does not include the sparingly soluble compounds that also replenish the soil solution as its concentration is depleted .. |
| 407 | Holford, I.C.R. & Doyle, A.D. | Influence of intensity/quantity characteristics of soil phosphorus tests on their relationships to phosphorus responsiveness of wheat under field conditions | 1992 | Phosphorus Cycling | Journal | Aust. J. Soil Res.; 30 (3); 343-356 | English | Hardcopy:Partial | Lab. expt. to study the correlation between soil P tests and wheat yield. Labile or plant-available P is widely regarded as being the same as adsorbed or isotopically exchangeable P, but this is not well correlated with the P uptake of plants. Chemical extraction, e.g. with acidic lactate, may give a better correlation, which implies that non-exchangeable mineral P is also an important part of the labile pool. | because the chemical composition of the labile pool will vary among soils, .. it seems unlikely that a universal measure of the quantity of labile P will ever be possible. |
| 571 | Holland, E.A. & Coleman, D.C. | Litter placement effects on microbial and organic matter dynamics in an agroecosystem | 1987 | Mulch; Soil Organic Carbon; Soil Microorganisms | Journal | Ecology; 68 (2); 425-433 | English | Hardcopy:Full | Lab. and field study to compare the effect of mulching and incorporating straw on SOM dynamics and microbial biomass. The surface-straw treatment showed 44% more fungal biomass, greater retention of added C in the total SOM and in the microbial biomass, higher cumulative respired CO2, slower straw decomposition, higher maximum net N immobilisation and reduced SOM loss, compared with the incorporated-straw treatment. The fungal biomass was, on average, only 0.35% of the bacterial biomass. | .. fungi may be important decomposers of the surface straw .. [but] less important decomposers of the incorporated residues.. surface residue placement increases fungal abundance .. |
| 95 | Holle, R. & Untiedt, H. | Crop rotations on organic farms in northern Germany and development of the wide- row system | 1999 | Miscellaneous | Book | Olesen, J.E., Eltun, R., Gooding, M.J., Jensen, E.S & Köpke, U. (eds); Designing & testing crop rotations for organic farming. Proceedings from an international workshop; | English | Hardcopy:Partial; Wordperfect:Full | Review of wheat growing in northern Germany by the Stute wide-row method | The quality effect of the wide-row system may be seen from a content of crude protein of 11.7% & of gluten of 24.0% ... The yield of the wide-row system is less, but the crude protein is higher than of the standard seeding. On average the difference between normal sowing & the wide-row system is about 0.2 t ha-1. |
| 1254 | Holtan-Hartwig, L., Dörsch, P. & Bakken, L. | Comparison of denitrifying communities in organic soils: kinetics of NO3- and N2O reduction | 2000 | Greenhouse Gases; Soil Microorganisms; Soil N Dynamics | Journal | Soil Biol. Biochem.; 32 (6); 833-843 | English | Hardcopy:Partial; PDF:Full | Lab. expt to identify possible differences in community composition among denitrifying bacteria under anaerobic conditions | The results .. suggest that intrinsic differences in community composition of soils exist, with consequences for the emission of N2O. |
| 1433 | Hooker, B.A., Morris, T.F., Peters, R. & Cardon, Z.G. | Long-term effects of tillage and maize stalk return on soil carbon dynamics | 2005 | Soil Organic Carbon; Tillage | Journal | Soil Sci. Soc. Am. J.; 69; 188-196 | English | Hardcopy:Partial; PDF:Full | 28-year field expt. to study the dynamics of relic and new SOC in maize fields under zero or conventional tillage and with (+) or without (-) residue removal | NT increased SOC significantly .. over CT in treatments with residue returned .. & .. in treatments with residue removed; .. a rapid cycling of returned C4-C suggests that the annual return of aboveground biomass may not increase soil C storage over the long term, once soils have reached a steady-state SOC level.; .. the relative half-life of relic C3-C was strongly influenced by tillage in the upper 15 cm of the soil, with C3-C being retained longer under NT mgmnt. |
| 562 | Hooper, D.U., Chapin, F.S., Ewel, J.J., Hector, A., Inchausti, P., Lavorel, S., Lawton, J.H., Lodge, D.M., Loreau, M., Naeem, S., Schmid, B., Setälä, H., Symstad, A.J., Vandermeer, J. & Wardle, D.A. | Effects of biodiversity on ecosystem functioning: a consensus of current knowledge | 2005 | Miscellaneous | Journal | Ecol. Monogr.; 75 (1); 3-35 | English | Hardcopy:Partial; Word:Partial | Review of current opinion on the relationship between biodiversity and ecosystem stability | The scientific community has come to a broad consensus on many aspects of the relationship between biodiversity and ecosystem functioning ..; Having a range of species that respond differently to different environmental perturbations can stabilise ecosystem process rates in response to disturbances and variation in abiotic conditions. |
| 598 | Hopfenberg, R. & Pimentel, D. | Human population numbers as a function of food supply | 2001 | Sustainability | Journal | Environ. Dev. Sustain.; 3; 1-15 | English | Hardcopy:Partial; PDF:Full | Review of the evidence of a positive causal connection between human population and food supply | .. hu |