Contents: Foreword. I. Introduction. II. Green-manuring practices: 1. Ecological background. 2. Cultivation practices. 3. Sub-tropical green-manuring practices. 4. Stem-nodulating legumes. 5. Azolla. 6. Green-manure-based crop rotations. 7. Transported green-manuring material. III. Accumulation of biomass and nitrogen: 1. Leguminous green manures. 2. Azolla. IV. Nutrient transformation in the soil: 1. Nitrogen. 2. Phosphorus. 3. Potassium, calcium, magnesium and sulphur. 4. Micronutrients. 5. Organic substances. V. Effect on soil properties: 1. Biological properties. 2. Electro-chemical and chemical properties. 3. Physical properties. VI. Reclamation of salt-affected soils: 1. Salt-tolerance of green manures. 2. Effect on base-exchange. 3. Influence on crop yields. VII. Responses of crops to green manuring: 1. Rice. 2. Maize. 3. Sorghum. 4. Wheat. 5. Cotton. 6. Potato. 7. Other annual field crops. 8. Sugarcane. 9. Residual effects. VIII. Conclusions: 1. Constraints. 2. Development and research needs. References. Annex: 1. List of green-manure species. 2. Biomass and N-accumulation of green manures in Asia, Africa and Latin America.

"The publication deals with green manuring, a subject of interest not only in rice cultivation but also in upland agriculture, where the practice is beneficial for the improvement of the physical and biological characteristics of soil as well as for the supply of plant nutrients for increased crop yields. Advantages, disadvantages and constraints in adopting green manuring practices are outlined. Labour, time and energy constraints, particularly under small-farm conditions, are highlighted. A large amount of available research data is reviewed in this publication, and future research needed are suggested."