Part I: Agropastoral research in the tropical savannas of Latin America. Part II: Methodological aspects of agropastoral research. Part III: Crops and forages as components of agropastoral systems. Part IV: Potential of agropastoral systems for the sustainable management of the tropical savannas of South America. Part V: Acquired experiences and the road to the future.

Technological constraints and opportunities in relation to class of livestock and production objectives; Trhe influence of socioeconomic factors on the availability and utilization of crop residues as animal feeds; Crop residues in Tropical Africa: trends in supply, demand and use; Cowpea and its improvement: key to sustainable mixed crop/livestock farming systems in West Africa; Dynamics of feed resources in mixed farming systems in Southeast, South Asia; West/Central Asia-North Africaand Latin America; Crop residues as a strategic resource in mixed farming systems; Alternatives to crop residues as feed resource in mixed farming systems; Alternatives to crop residues for soil amendment; Crop residues for feeding animals in Asia: technology development and adoption in crop/livestock systems; The national perspective: a synthesis of country reports presented at the Workshop.

Importance of agro-pastoral systems in Brazil; Grassland management technology for sustainable agro-pastoral systems in the subtropical zone of Brazil; Results of soybean yield, animal liveweight gain and soil fertility changes in agro-pastoral systems; Nitrogen dynamics in agro-pastoral system of Brazil; Characterization of nitrogen utilization by tropical grasses in brazilian savannas; Soil organic residues accumulation in agro-pastoral systems in the cerrados of Brazil; Effects of termite activities on nutrient recycling in agro-pastoral system; Inhibition of nitrification in Brachiaria humidicola; Diagnosis of pasture degradation by multi-temporal satellite imagery; Problems and prespectives of regional land conservation systems in relation to the pantanal wetlands; Tropical forage breeding in Embrapa: current situation and prospects; Economic evaluation of the agro-pastoral system; Agro-pastoral systems in subtropical Brazil and possibility of extension.

Soil organic matter is a reservoir for plant nutrients, provides water-holding capacity, stabilizes soil structure against compaction and erosion, and thus determines soil productivity. All agriculture to some degree depends on soil organic matter. It has long been known that soil organic matter declines when land is taken into cultivation, and that the productivity of new agricultural land is governed by fertility contributions from decomposing natural organic matter. The expansion of agriculture to ever new and more fragile lands, particularly in tropical and developing regions, causes environmental degradation with local effects on soil quality, regional effects on landscape integrity and water quality, and global effects on carbon cycles and the atmosphere. This book summarizes current knowledge of the properties and dynamics of soil organic matter in the tropics, its role in determining soil quality, its stability and turnover, and the options for management in the context of tropical landuse systems, for a readership of resource scientists, economists and advanced students. Maintenance of organic matter is critical for preventing land degradation. Case studies and practical applications are therefore an important part of the book, as are the exploration of future directions in research and management.