Microbiology of Tropical Soils and Plant Productivity (Developments in Plant and Soil Sciences, 5)

It is an established fact that we must continually increase and improve agricultural production if we are to meet even the minimum requirements of a growing popu­ lation for food, shelter, and fuel. In recent years, the introduction of new plant varieties and the extensive use of fertilizers have effectively increased crop yields, but intensifying agricultural methods has often led to depleting soil fertility. Two examples of the harmful consequences of intensive farming practices are the loss of up to 2.5 cm of topsoil every 15 years in the United States through erosion and the alarming rise in environmental pollution through widespread use of pesticides. Countless other processes affecting the activity of soil micro flora and the inter­ actions between microorganisms and plants may pose an equal danger to soil equilibrium, but their potential hazards are often overlooked because of an insufficient understanding of soil microbiology on the part of scientists. In the first published study of its kind, the authors of this book have attempted to address major aspects of the microbial activity of soil in the tropics. Tropical conditions serve as an ideal context for a discussion of soil microbiology, since biological processes in the soil are particularly active in tropical environments in comparison to other settings and in relation to physical and chemical processes. Front Matter....Pages I-IX Nitrogen balance in tropical agrosystems....Pages 1-36 Nitrogen fixation by legumes in the tropics....Pages 37-73 Heterotrophic N 2 fixation in paddy soils....Pages 75-107 N 2 -fixing tropical non-legumes....Pages 109-146 Free — living blue — green algae in tropical soils....Pages 147-168 Azolla—Anabaena symbiosis — its physiology and use in tropical agriculture....Pages 169-185 Denitrification in rice soils....Pages 187-208 Endomycorrhizae in the tropics....Pages 209-251 Ectomycorrhizae in the tropics....Pages 253-269 The significance of the biological sulfur cycle in rice production....Pages 271-317 Back Matter....Pages 319-328 The use of organic residues as a means of maintaining and increasing soil fertility is of long-standing. 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. "Based on a workshop, organized by the International Center for Agricultural Research in the Dry Areas, which was sponsored by the International Center for Agricultural Research in the Dry Areas and the United Nations Development Programme." -- Verso of t.p Proceedings of the First International Symposium on Foliar Fertilization, organized by Schering Agrochemical Division, Special Fertilizer Group, Berlin (FRG), March 14-16, 1985 Proceedings of a Workshop in the EEC Programme of Coordination and Research on Effluents from Livestock Edited By Paul L.g. Vlek. First Published In Fertilizer Research, Vol. 7. Includes Bibliographies.