The second edition of this book, first published in 1991 and intended for students and researchers, contains revised and updated material on the theory and practice of nitrogen fixation in tropical cropping systems. There are 15 chapters in 3 parts. Part I, Introduction, contains 5 chapters on tropical environments (climate, soils and cropping systems), nitrogen fixing organisms, the process of nitrogen fixation, assessment of the role of nitrogen fixation, and cycling of nitrogen in tropical cropping systems. Part II, Tropical crops and cropping systems, comprises 7 chapters on freeliving, root-associated and endophytic nitrogen fixing bacteria of cereal crops and grasses, cyanobacteria and Azolla as green manure for wetland rice, grain legumes, legumes as green manures and cover crops, forage legumes, understorey legumes and shade trees in plantation crops, and nitrogen fixing trees in agroforestry. Part III, optimizing nitrogen fixation, includes 3 chapters on environmental constraints, approaches to enhancement, and future impacts on nitrogen fixation in tropical agriculture. A list of common names and subject index are included.

This book presents the science, application, and politics of the use of nitrogen-fixing crop plants across the globe in various environments. Nitrogen fixation can help provide a growing population with a nutritious, environmentally friendly, sustainable food supply. From new "omics" approaches to the role of nitrogen fixation in mitigating greenhouse gas emissions, from farming strategies in nonindustrialized nations to nitrogen fixation in the global economy, scientists will find the key issues and expanding research areas, and how they contribute to the next wave of advancements related to agriculture and the environment

Agronomic crops have provided food, beverages, fodder, fuel, medicine and industrial raw materials since the beginning of human civilization. More recently, agronomic crops have been cultivated using scientific rather than traditional methods. However, in the current era of climate change, agronomic crops are suffering from different environmental stresses that result in substantial yield loss. To meet the food demands of the ever-increasing global population, new technologies and management practices are being adopted to boost yields and maintain productivity under both normal and adverse conditions. Further, in the context of sustainable agronomic crop production, scientists are adopting new approaches, such as varietal development, soil management, nutrient and water management, and pest management. Researchers have also made remarkable advances in developing stress tolerance in crops. However, the search for appropriate solutions for optimal production to meet the increasing food demand is still ongoing. Although there are several publications on the recent advances in these areas, there are few comprehensive resources available covering all of the recent topics. This timely book examines all aspects of production technologies, management practices and stress tolerance of agronomic crops.

Low external-input technology (or LEIT) is an increasingly prominent subject in discussions of sustainable agriculture. There are growing calls for self-sufficient agriculture in an era experiencing diminishing returns from reliance upon expensive synthetic pesticides and fertilizers. There are many reasons to support strategies for low external input farming, including a concern for environmental sustainability, increased attention to resource-poor farmers and marginal environments, and the conviction that a better use of local resources in small-scale agriculture can improve farm productivity and innovation. But despite the increased attention to self-sufficient agriculture, there is little evidence available on the performance and impact of LEIT. This book examines the contributions and limitations of low external input technology for addressing the needs of resource-poor farmers. For the first time a balanced analysis of LEIT is provided, offering in-depth case studies, an analysis of the debates, an extensive review of the literature and practical suggestions about the management and integration of low external input agriculture in rural development programmes.