Nitrogen Fixation In Agriculture Forestry Ecology And The Environment

Sustainability has a major part to play in the global challenge of continued development of regions, countries, and continents all around the World and biological nitrogen fixation has a key role in this process. This volume begins with chapters specifically addressing crops of major global importance, such as soybeans, rice, and sugar cane. It continues with a second important focus, agroforestry, and describes the use and promise of both legume trees with their rhizobial symbionts and other nitrogen-fixing trees with their actinorhizal colonization. An over-arching theme of all chapters is the interaction of the plants and trees with microbes and this theme allows other aspects of soil microbiology, such as interactions with arbuscular mycorrhizal fungi and the impact of soil-stress factors on biological nitrogen fixation, to be addressed. Furthermore, a link to basic science occurs through the inclusion of chapters describing the biogeochemically important nitrogen cycle and its key relationships among nitrogen fixation, nitrification, and denitrification. The volume then provides an up-to-date view of the production of microbial inocula, especially those for legume crops.

This volume covers all aspects of fundamental and applied nitrogen-fixation research, extending from biochemistry and chemistry through genetics, regulation and physiology to agricultural practice and environmental impact. It describes recent progress on studies of potential catalysts for nitrogen fixation; how the N2-fixing process is regulated in living cells; the use and impact of genetics and genomics on our understanding of the biological process; the wide variety of associations of nitrogen-fixing microbes with plants, including the formalized Rhizobium-legume and actinorrhizal associations as well as the less formalized associative and endophytic interactions; and the impact of nitrogen fixation in agriculture and forestry, including its effect on the environment. This volume provides an up-to-date referenced source, which can be readily accessed by all practicing and otherwise interested proponents of nitrogen fixation research, including those with related interests in the areas of plant and microbial science, genomics, plant-microbe interactions, genetics and regulation, plant growth and biocontrol, agriculture, forestry, ecology, taxonomy and evolution.

Sustainability has a major part to play in the global challenge of continued development of regions, countries, and continents all around the World and biological nitrogen fixation has a key role in this process. This volume begins with chapters specifically addressing crops of major global importance, such as soybeans, rice, and sugar cane. It continues with a second important focus, agroforestry, and describes the use and promise of both legume trees with their rhizobial symbionts and other nitrogen-fixing trees with their actinorhizal colonization. An over-arching theme of all chapters is the interaction of the plants and trees with microbes and this theme allows other aspects of soil microbiology, such as interactions with arbuscular mycorrhizal fungi and the impact of soil-stress factors on biological nitrogen fixation, to be addressed. Furthermore, a link to basic science occurs through the inclusion of chapters describing the biogeochemically important nitrogen cycle and its key relationships among nitrogen fixation, nitrification, and denitrification. The volume then provides an up-to-date view of the production of microbial inocula, especially those for legume crops.

Poverty is a severe problem in Africa, Asia, South America and even in pockets of the developed world. Addressing poverty alleviation via the expanded use of biological nitrogen fixation in agriculture was the theme of the 15th International Congress on Nitrogen Fixation. Because nitrogen-fixation research is multidisciplinary, exploiting its benefits for agriculture and environmental protection has continued to attract research by diverse groups of scientists, including chemists, biochemists, plant physiologists, evolutionary biologists, ecologists, agricultural scientists, extension agents, and inoculant producers. The 15th International Congress on Nitrogen Fixation was held jointly with the 12th International Conference of the African Association for Biological Nitrogen Fixation. This joint Congress was hosted in South Africa at the Cape Town International Conv- tion Centre, 21–26 January 2007, and was attended by about 200 registered participants from 41 countries world-wide. During the Congress, some 100 oral and approximately 80 poster papers were presented. The wide range of topics covered and the theme of the Congress justifies this book’s title, Nitrogen Fixation: Applications to Poverty Alleviation.

Many people learn the rudiments of the nitrogen cycle while at school, but the details of the various processes in the cycle are still not widely understood. Some of them are of great current interest, such as the use of nitrogen fixing crops to feed an increasing world population and the problems of pollution of groundwaters by nitrates. Denitrification (forming nitrogen gas) as a way of getting rid of waste from human and intensively farmed animals. This book describes the general processes of the nitrogen cycle, then gives examples of how the cycle is modified under particular ecological and geographical conditions. These examples are drawn from all the major areas of the world, and the impact of man via agriculture, forestry and fuel combustion is discussed. Numerous references are included. The book provides a background for all those whose specialist interests interact with nitrogen cycling, whether they are involved in research or have responsibility for managing the environment.

Biological nitrogen fixation (BNF) - the conversion of molecular nitrogen into ammonia - is one of the most important reactions in ecology and agriculture. It is performed exclusively by microbes (prokaryotes) that live in symbiosis with plants. This book summarizes the latest research on this reaction, the participating microbes and the genetics of how their relevant genes could be transferred into the plants. In the light of a more sustainable and less ecologically damaging agriculture, this is becoming an increasingly pressing issue.

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.