The Role of Organic Matter in Modern Agriculture (Developments in Plant and Soil Sciences, 25)

The use of organic residues as a means of maintaining and increasing soil fertility is of long-standing. This tradition has been somewhat neglected since the introduc­ tion of mineral fertilizers at low cost. More and more farmers and scientists are now showing renewed interest in the proper and effective use of org~tnic residues, composts and other recycled organic additives. The role and function of organic amendments in modern agricultural systems have become topics of major interest in the scientific and agricultural communities. Research work on residue disposal has provided new concepts on the interaction between organic components and soils as well as new handling technologies (e. g. pelletizing of organic residues). The trend to conserve energy has led scientists to study the minimal tillage system, to find ways of replacing conventional inorganic fertilizers with natural organic prod­ ucts or microbial preparations, and to develop new composting methods. The drive to achieve higher yields in commercial greenhouse farming has led to a search for optimum substrates as growth media and for improved management techniques. This has led to the introduction of organic substitutes for peat, nota­ bly those originating from agricultural wastes. Another important aspect is the current interest in organic farming, where use of synthetic chemicals is avoided or prohibited. An increasing percentage of the population in highly developed countries is willing to pay premium prices for food produced on soils where inorganic fertilizers and other agricultural chemicals have not been used. Front Matter....Pages I-XIV Organic residues in modern agriculture....Pages 1-10 Front Matter....Pages 11-11 Effects of organic matter on nitrogen and phosphorus supply to plants....Pages 13-27 The role of organic matter and ammonium in producing high corn yields....Pages 29-54 Nitrogen transformations in Histosols....Pages 55-70 Front Matter....Pages 71-71 Soil organic matter interactions with trace elements....Pages 73-116 Effect of soil redox conditions on microbial oxidation of organic matter....Pages 117-156 Front Matter....Pages 157-157 Soil microorganisms, soil organic matter and soil fertility....Pages 159-168 The role of organic matter in the introduction of biofertilizers and biocontrol agents to soils....Pages 169-179 Front Matter....Pages 181-181 Soil organic matter extraction, fractionation, structure and effects on soil structure....Pages 183-208 Sewage sludge organic matter and soil properties....Pages 209-253 Front Matter....Pages 255-255 Peat and peat substitutes as growth media for container-grown plants....Pages 257-287 Effects of composts in growth media on soilborne pathogens....Pages 289-306 Sewage Ind. Wastes 28, 1 32-1 35 3 Anderson G. 1980 Assessing organic phosphorus in soils. In The Role of Phosphorus in Agriculture, Eds. EC Sample and EJ ...