The need for exploration, conservation, and sustainable utilization of bioresources is undeniable for the survival and growth of mankind. This new book throws light on new and recent research on and development of effective strategies for sustainable utilization of bioresources using modern tools and techniques to help meet this challenge. This volume addresses the utilization of bioresources in therapeutics, in biofuel, in agriculture, and in environmental protection. Beginning with the diverse potential applications of bioresources in food, medicine, and cosmetics, the volume goes on to address the various different underutilized bioresources and their sustainable uses. It discusses important advances in biofuel and patents that highlight recent developments that address the energy crises and the continuously fluctuating cost of petroleum. It explores new renewable energy sources from bioresources and their sustainable utilization in the bioenergy and biofuel industry. Several chapters focus on the sustainable utilization of bioresources in the agricultural sector. The volume considers that developing countries have huge agricultural resources that could be employed for production of value-added byproducts for the sustainable development of a bio-based economy. The book discusses efficient use of underexploited natural bioresources, new chemical approaches for the generation of novel biochemicals, and the applications of genetics approaches for bioresource conservation and production of value-added products. Further, strategies for the production of biopesticides utilizing bioresources are also discussed.

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.

It is an established fact that we must continually increase and improve agricultural production if we are to meet even the minimum requirements of a growing popu lation for food, shelter, and fuel. In recent years, the introduction of new plant varieties and the extensive use of fertilizers have effectively increased crop yields, but intensifying agricultural methods has often led to depleting soil fertility. Two examples of the harmful consequences of intensive farming practices are the loss of up to 2.5 cm of topsoil every 15 years in the United States through erosion and the alarming rise in environmental pollution through widespread use of pesticides. Countless other processes affecting the activity of soil micro flora and the inter actions between microorganisms and plants may pose an equal danger to soil equilibrium, but their potential hazards are often overlooked because of an insufficient understanding of soil microbiology on the part of scientists. In the first published study of its kind, the authors of this book have attempted to address major aspects of the microbial activity of soil in the tropics. Tropical conditions serve as an ideal context for a discussion of soil microbiology, since biological processes in the soil are particularly active in tropical environments in comparison to other settings and in relation to physical and chemical processes.

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.

The Fifth International Symposium on Nitrogen Fixation with Non-legumes was held in Florence (Italy) on 10-14 September, 1990. Earlier Symposia of this series were held in Piracicaba (Brazil), Banf Alberta (Canada), Helsinki (Finland) and Rio De Janeiro (Brazil). The Symposium's main objectives were to bring together scientists working in many different fields of nitrogen fixation, to stimulate discussion on this important process and to have an appraisal of the most recent studies concerning nitrogen fixation with non-legumes. The Symposium was attended by 230 scientists from 32 different countries. This volume collects the contributions of 65 lectures and 87 posters, which are an up-to-date account of the state of knowledge on biological nitrogen fixation with non-legumes. The book provides a valuable reference source not only for specialists in nitrogen fixation, but also for researchers working on related aspects of agronomy, biochemistry, genetics, microbiology, molecular biology and plant physiology. It is with great pleasure that we aknowledge the contributions of the authors in assuring the prompt pubblication of this volume. We would also like to express our thanks to Kluwer Academic Publishers B.V. for the publication of these Proceedings. M. Polsinelli R. Materassi M. Vincenzini ORGANIZING COMMITTEE President M. Polsinelli M. Vincenzini Secretary F. Favilli Treasurer E. Galli E. Gallori L. Giovannetti R. Materassi M.P. Nuti M.R. Tredici SCIENTIFIC COMMITTEE M. Bazzicalupo Florence, Italy H. Bothe Cologne, West Germany R.H. Burris Madison, U.S.A.

Chemical fertilizers have had a significant impact on food production in the recent past, and are today an indispensable part of modern agriculture. On the other hand, the oil crisis of the 1970s and the current Middle East problems are constant reminders of the vulnerability of our fossil fuel dependent agriculture. There are vast areas of the developing world where N fertilizers are neither available nor affordable and, in most of these countries, balance of payment problems have resulted in the removal of N fertilizer subsidies. The external costs of environmental degradation and human health far exceed economic concerns. Input efficiency of N fertilizer is one of the lowest and, in turn, contributes substantially to environmental pollution. Nitrate in ground and surface waters and the threat to the stability of the ozone layer from gaseous oxides of nitrogen are major health and environmental concerns. The removal of large quantities of crop produce from the land also depletes soil of its native N reserves. Another concern is the decline in crop yields under continuous use of N fertilizers. These economic, environmental and production considerations dictate that biological alternatives which can augment, and in some cases replace, N fertilizers must be exploited. Long-term sustainability of agricultural systems must rely on the use and effective management of internal resources. The process of biological nitrogen fixation offers and economically attractive and ecologically sound means of reducing external nitrogen input and improving the quality and quantity of internal resources. In this book, we outline sustainability issues that dictate an increased use of biological nitrogen fixation and the constraints on its optimal use in agriculture.

Sharply focused, up-to-date information on microbial biofertilizersincluding emerging options such as Piriformospora indica and Matsutake The Handbook of Microbial Biofertilizers provides in-depth coverage of all major microbial biofertilizers (rhizobia, arbuscular mycorrhizal fungi, and cyanobacteriaas well as new

Table of contents

This volume is written with the objective of covering the basic issues in biological nitrogen fixation such as: the physiology, biochemistry and molecular genetics of nitrogen fixation; and the role of signal molecules and host gene expression in nodulation and nitrogen fixation. The book also details recent developments in biofertilizer technology, such as: the immobilization of cyanobacteria; endophytic nitrogen fixation; and solubilization and mobilization of nutrients by phosphobacteria and VA mycorrhiza and their role as bioinoculants.