BIOLOGICAL NITROGEN FIXATION : RESEARCH NEEDS FOR AGRICULTURAL DEVELOPMENT IN THE TROPICS

Nitrogen, essential for plant growth and for protein and carbohydrate production, is critically important in the growing world food shortage. The use of legumes and inoculants to produce fixed nitrogen is considered as an alternative to factory fixation of N2. Manufacturing fertilizer nitrogen entails high costs and dependence on fossil fuels; using it requires information about the efficient use of fertilizer which is absent or unavailable to small farmers in LDC"s. Legumes are a major part of the native vegetation in tropical regions, yet only a few species have been developed for agricultural use. Optimal culture of legumes requires both an adequate supply of legume seeds and cultures of rhizobia and proper use by the grower. Principles regarding various aspects of biological nitrogen fixation, adapted from six recently published reviews are listed. Priorities are discussed for research activities, for facilities and for a training program in biological nitrogen fixation, as they apply to the immediate needs of LDC"s.