Concern over the depletion of world energy resources and the increase in the cost of nitrogen fertilizer has prompted considerable interest and research in biological nitrogen fixation. This volume discusses the most recent advances in the field, with chapters written by experts on the ecology, physiology, biochemistry and genetics of biological nitrogen fixation. Grain legumes, rice, sugar cane, sorghum and millet are all covered in the book. Some of the chapters particularly focus on the genetics and molecular biology of nitrogen fixing bacteria, and summarize the biotechnological strategies that are being applied in the hope of rendering plants self-sufficient with regard to nitrogen fertilization.