Biological Nitrogen Fixation In Farming Systems Of The Tropics

The symposium's objectives included an appraisal of the most recent studies relating to microbiological nitrogen fixation in tropical soils, consideration of aways and means of improving management of soils and crops in tropical farming systems to increase biological nitrogen fixation, of exploring ways of concurrently improving both legumes and other hosts and their symbionts to enhance nitrogen fixation, and of recommending the research needed and means of collaborating in the research effort.

Nitrogen fixation by leguminous plants is especially important when farmers are trying to minimise fertilizer use for cost or environmental reasons. This second edition of the highly successful book, first published in 1991, contains thoroughly updated and revised material on the theory and practice of nitrogen fixation in tropical cropping systems.

The International Workshop on Biological Nitrogen Fixation for Increased Crop Productivity, Enhanced Human Health and Sustained Soil Fertility was held in June 2002 at ENSAM-INRA, Montpellier, France. The main goal of the workshop was to define research strategies for a Challenge Program initiative on Biological Nitrogen Fixation, and develop a pre-proposal based on the concept note submitted and approved by the CGIAR iSC. More than 35 participants from various scientific disciplines, research institutions and from four different continents (Africa, Asia, Americas and Europe) attended the workshop. This book, based on the proceedings of the workshop, takes a holistic approach to harnessing legume BNF technologies, starting from a socioeconomic perspective, and progressing to agronomic and genetic options, and bringing together innovative aspects and participatory research strategies.

Reprinted from Plant and Soil, v.174, nos.1-2 (1995), this volume is devoted to discussions on the role of biological nitrogen fixation (BNF) in agricultural sustainability. Papers presented on BNF in crop forage and tree legumes are augmented with discussion of integrated farming systems involving BNF, soil and N management, and recycling of legume residues. BNF by non-legumes is discussed and attempts to transform cereals into nodulating plants are critically reviewed. Also described are advances in the development of new methodologies to understand symbiotic interactions and to assess N-2 fixation in the field; means of enhancing BNF through plant and soil management; breeding and selection; problems encountered in exploiting BNF under farmers' field conditions; and promising approaches to improve BNF exploitation. Lacks a subject index. Annotation copyright by Book News, Inc., Portland, OR

Biological nitrogen fixation in tropical agrosystems: twenty years of biological nitrogen fixation research in Africa; Sustainable agriculture: definition and measurement; Biological nitrogen fixation systems in tropical ecosystems: an overview; A protocol for screening legumes as soil-improving crops; The sustenance of tropical agriculture with multipurpose azolla; Facteurs pedoclimatiques limitant la lixation biologique l'azole; Response of some tropical nitrogen-fixing woody legumes to drought and inoculation with mycorrhiza; Improvement to the Phaseolus/Rhizobium symbiosis, with particular reference to the Caribbean region; Effect of pest management systems on biological nitrogen fixation; Agronomic evaluation of a rock phosphate as a phosphorus source for Leucaena leucocephala grown on an utisol; Nodulation of soybean grown under field conditions and inoculated with Bradyrhizobium japonicum strains; Effect of fertilization and Rhizobium inoculation on the growth of Leucaena and Gliricidia on an alfisol in south-western Nigeria; Early growth and nodulation in Leucaena and Gliricidia and the effects or pruning on biomass productivity; Comparative stude on the growth and productivity of Sesbania and Leucaena in the Central Plateau region, Rwanda; Supernoculation and non-nodulation mutants of soybean; Genetically improved rhizobia and their use in agriculture; Sustainability of nitrogen-fixing cropping systems: Nodulation and nitrogen fixation and transfer in a cowpea/rice cropping system; The role of legumes in sustaiing soil productivity and controlling soil erosion; Fitting soil-improving legumes into inland valley rice-baes cropping systems in West Africa; Herbage yield and soil fertility restoration potential of some tropical forage legumes.

Cerrado a region of high agricultural potential that requires nitrogen; Potential for nitrogen fixation in tropical legumes and grasses; Free-living bacteria; Nitrogen fixation by soil algae of temperate and tropical soils; Contribution of the legume-Rhizobium symbiosis to the ecosystem and food production; Plant influence in symbiotic nitrogen fixation; Plant photosynthesis; Interactions of plant photosynthesis with dinitrogen fixation and nitrate assimilation; Some aspects of the Alnus-type root nodule symbiosis; Legumes and acid soils; Micronutrient requirements of legume-Rhizobium symbiosis in the tropics; Ecology of legume-Rhizobium symbiosis; Nitrogenase systems; Relationship between hydrogen metabolism and nitrogen fixation in legumes; Ammonia assimilation in N2-Fixing systems; Genetics and regulation of nitrogen fixation; Leghaemoglobin, oxygen supply and nitrogen fixation: studies with soybean nodules; Nitrogen fixation by Rhizobium spp. in laboratory culture media; Limiting factors in grass nitrogen fixation; Physiology and biochemistry of Spirillum lipoferum; Taxonomy of the root-associated nitrogen fixing bacterium Spirillum lipoferum; Abstracts of original papers; Abstracts of posters.