Biological nitrogen fixation (BNF) has become important in rice farming systems because this process diminishes the need for expensive chemical fertilizers which have been associated with numerous health and environmental problems. The extensive exploitation of BNF would provide economic benefits to small farmers, avoiding all malign influences of chemical fertilizers. Meanwhile, advances in biotechnology have brought rice genetics to the threshold of new opportunities for increasing rice production. This volume focuses, in six different sessions, on the role of BNF in the improvement of rice production in the light of the current state of the art of BNF technology transfer and diffusion. New ideas on BNF technology in research, extension information and inoculant technology are also included, together with the socio-economic impacts of using BNF in rice farm systems.

Foreword. Preface. Some Comments about a Better Use of Biological Nitrogen Fixation in Rice Cultivation; J. Balandreau, P. Roger. I: Rhizobia-Legume Symbiosis, Green Manuring Crops And Rice Soils. 1. Rhizobial Biofertilizers: The Most Promising BNF Technology for Increased Grain Legume Production in Bangladesh; M.A. Sattar, et al. 2. Effect of Heavy Metals on Legume Rhizobium Symbiosis; S.C. Pal. 3. Effect of Straw Incorporation on Soil N-Pools in Submerged Rice; L. van Holm, et al. 4. The Use of Organic Residues in Increasing Crop Production in Wheat Mungbean, T. Aman Cropping System on Red Brown Terrace Soils; D. Khanam, et al. 5. Leguminous Green Manures in Rice-Based Cropping Systems; M. Becker. 6. Use of Green Manuring Crops in Rice Field For Sustainable Production in Bangladesh Agriculture; N.I. Bhuiyan, S.K. Zaman. 7. Prospect of Dhaincha (Sesbania rostrata) Intercropping with T. Aus in a T. Aus-T. Aman Cropping Pattern; S.K. Zaman, et al. 8. Pedology of the Rice Soils of Bangladesh; S.M. Saheed, M.S. Hussain. II: Azolla - Anabaena Association. 9. Does Azolla Have Any Future in Agriculture? C. Van Hove, A. Lejuen. 10. Utilization of Azolla in Rice Production in West Africa: Potentials and Constraints; V. N. Nguyen. 11. Cultivation and Uses of Azolla in Egypt; A.A. El-Bassel, I.M. Ghazi. III: Blue Green Algae (Cyanobacteria). 12. Prospect and Potentiality of Cyanobacteria as an Alternative Source of Nitrogen Fertilizer in Bangladesh Rice Cultivation; Z.N.T. Begum, et al. 13. Contribution of Cyanobacterization to Rice Growth and Performance Under Different Field Stand Densities and Levels of Combined Nitrogen; Y.G. Yanni. 14. Ecological Aspects of Cyanobacteria from the Rice Fields of Corrientes (Argentina); C. Prosperi, et al. 15. Contribution of Biological Nitrogen Fixation to Rice Production in a Mediterranean Rice Field; E. Fernandez Valiente, et al. 16. Enrichment of Indigenous Blue-Green Algal Population in Rice Fields and Evaluation of Their Effects in Rice Culture; M.A. Hashem, et al. IV: Rice Root Associated Soil Microflora. 17. Abundance and Isolation of Nitrogen Fixing Bacteria in Two Major Rice Soils of Bangladesh; M. Rahman, et al. 18. Burkholderia vietnamiensis, A New Nitrogen-Fixing Species Associated with Rice Roots, Isolated from an Acid Sulphate Soil in Vietnam: Plant Growth-Promoting Effects on Rice; V. Tran Van, et al. 19. Specificity of Root Colonization by Symplasmata-Forming Enterobacter agglomerans; W. Achouak, et al. 20. Nitrogen Fixation by Azospirillum brasilense Isolated from Rice Fields of Bangladesh; Z.U.M. Khan, M.A. Akond. V: Application of Biotechnology in Rice Culture. 21. Biotechnological Aspects of Growth Promotion in Rice by Bacterial Inoculants; A. Hartmann. 22. Azospirillum Phylogeny Based on 16S rRNA Sequences; R. Bally, et al. 23. Increase Growth and Yield of Rice by Treating Seeds and Spreading Plants with Non-Nitrogen Fixing Bacteria; Tang Wen-Hua. Author Index.