Bøger af William E. Newton

Nitrogen availability is one of the most critical factors that limits plant productivity. The largest reservoir of nitrogen is the atmosphere, but this gaseous molecular nitrogen only becomes available to plants through the biological nitrogen fixation process, which only prokaryotic cells have developed. The discovery that microbes were providing fixed nitrogen to legumes and the isolation of the first nitrogen-fixing bacteria occured at the end the 19th Century, in Louis Pasteur's time. We are now building on more than 100 years of research in this field and looking towards the 21st Century. The International Nitrogen Fixation Congress series Started more than 20 years ago. The format of this Congress is designed to gather scientists from very diverse origins, backgrounds, interests and scientific approaches and is a forum where fundamental knowledge is discussed alongside applied research. This confluence of perspectives is, we believe, extremely beneficial in raising new ideas, questions and concepts.

Genomes and Genomics of Nitrogen-fixing Organisms This is Volume 3 of a seven-volume series on all aspects of Nitrogen Fixation. The series aims to be the definitive authority in the field and to act as a benchmark for some years to come. Rather than attempting to cram the whole field into a single volume, the subject matter is divided among seven volumes to allow authors the luxury of writing in depth with a comprehensive reference base. All authors are recognized practicing scientists in the area of their contribution, which ensures the high quality, relevance, and readability of the chapters. In establishing the rationale for, and the organization of, this book, we realized the need to divide it into two sections. The first section should be organism based and should review our current knowledge of the genomes of nitrogen-fixing organisms and what these nucleotide sequences tell us. The second section should then be technology based. It should review what technologies are available to mine the data inherent in the nucleotide sequences and how they are now being used to produce gene-function data from differential gene expression.

The 12th International Congress on Nitrogen Fixation was held in Foz do Iguacu, Parana State, Brazil, from the 12th to 17th of September, 1999. This volume constitutes the proceedings of this Congress and represents a compilation of the presentations by scientists from 38 countries who came to discuss the progress made, to exchange views and to collaborate. Since the first meeting in Pullman, Washington, USA, in 1974, this series of Congresses has been held three times in the United States, four times in Western Europe, in Australia, Mexico and Russia, and now for the first time in South America. Brazil was a most appropriate choice because Brazilian agriculture is especially dependent on biological nitrogenfixation. An important example is the soybean crop. The 30 million metric tons of grain produced each year relies solely on symbiotic nitrogen fixation. N-fertilizers are expensive in Brazil and, in the absence of the biological process, this crop would require 4-5 M tonnes of N at an annual cost of almost 1 billion dollars. Crop rotation, soil reclamation, forestry, forage mixed cropping, intercropping with grasses and legumes, associative nitrogen fixation with non-legume crops, such as sugarcane, and other agricultural practices in Brazil are also dependent on biological nitrogen fixation. The Brazilian experience with biological nitrogen fixation is a paradigm to be followed by all countries where nitrogen fertiliser is expensive or where present day environmental concerns demand a feasible, efficient and inexpensive alternative to chemical N-fertilizers.