Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: March 24, 1998
Publication Date: N/A
Technical Abstract: Although we have made striking advances in understanding the molecular and biochemical components regulating symbiotic N2 fixation, this has yet to be translated into applied improvements. In fact, over the last 40 years the importance of legume symbiotic N2 fixation to agriculture has been overlooked, if not forgotten. This is astounding since biological N2 fixation is the single-most important factor impacting the development of more sustainable farming systems. Approximately 90 million metric tons of N are fixed by legume nitrogenase yearly. The doubling of the Earth's population expected early in the new millennium necessitates that we reaffirm the significance of legume N2 fixation in cropping systems. Moreover, we must redefine the economic and social benefits of N2 fixing crops in sustainable agriculture. This will require accurate documentation of reduced fertilizer N expenses, improved water quality and soil health, and reduced pesticide inputs accruing due to the use of N2 fixing species in agriculture. Nontraditional and novel roles for legumes in cropping systems such as biofuels, bioremediants, and sources of industrial and pharmaceuticals will contribute to their enhanced use in sustainable systems. Both traditional and biotechnological approaches will be required to increase yield and maintain high rates of N2 fixation in legume crops.