|Graham, Peter - UNIVERSITY OF MINNESOTA|
Submitted to: Field Crops Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 7, 2000
Publication Date: N/A
Interpretive Summary: The importance of nitrogen to agricultural production is well known. However, its use is a conundrum. Sufficient nitrogen is required for crop yields and quality. Yet overuse of nitrogen fertilizer is a major pollution problem for intensive agriculture. The use of nitrogen derived from symbiotic nitrogen fixation is essential to agricultural sustainability and deffective management of nitrogen in the environment. Although significant progress has been made in the biochemistry, genetics, and molecular biology of symbiotic nitrogen fixation, little of these fundamental advances have been translated into applied improvements. The literature research reported in this overview identifies 7 research imperatives that will lead to on- farm increases in symbiotic nitrogen fixation. These research imperatives include: plant improvement in biological nitrogen fixation; development of acid tolerant rhizobia and legumes; improvements in phosphorus utilization by both legume plant and microsymbiont's enhanced use of nitrogen fixing species in crop rotations; identification and use of salt tolerant symbiotic interactions; enhanced strain and inoculant quality and viability; and enhanced collaboration between applied agriculturalists and biotechnologists. These findings are important because they provide a research framework for administrators and funding agencies to consider in funding decisions. The information will be useful to scientists and administrators interested in improving the environment and in sustainable agriculture.
Technical Abstract: Recent publications point to a decline in agricultural dependence on symbiotic nitrogen (N2) fixation and in the use of rhizobial inoculants. This review contrasts the potential contribution of biologically fixed N to intensive and extensive agricultural systems and examines opportunities for continued major contributions in the latter. It identifies six research and dextension areas in which in-depth efforts are still needed and examines some opportunities for improved N2 fixation likely to arise through advances in molecular biology.