N - fixation, limiting factors

Evaluation covers the period 4/76-10/78 and is based on document review and discussions with the project officer. Project research has generated a great deal of valuable information at minimal cost. A total of 25 grants ranging from $45,000-75,000 have been made to researchers at 16 State Agricultural Experiment Stations; seven grants include cooperative research by scientists in developing countries. At least ten LDC graduate students are or will be conducting research under the project. Common beans, cowpeas, peanuts, chick peas, mung beans, pigeon peas, lentils, broadbeans, and alfalfa are among the crops being investigated. Research topics include factors limiting the viability of rhizobia in the inoculant, methods of field inoculation, the viability and infectiveness of inoculated rhizobia after soil application, and factors limiting nitrogen fixation by the host crop. Significant findings obtained include: some rhizobial strains are compatible with seed fungicides; genetic improvement in peanuts for BNF is feasible; large variations in BNF potentials exist in cowpeas and mung beans; and cowpeas and mung beans exhibit some genetic tolerance to high temperatures and saline-sodic soils. Project management has been excellent. The project"s small grant funding approach combined with follow-up investigations and annual meetings with researchers has proven very successful. Recommendations are to: continue the project at its current funding level for three years; emphasize dissemination of project findings; focus research on primary constraints to exploiting BNF; and establish a consolidated program to develop a BNF technology package for LDC crops and cropping systems, conduct studies of the economic benefits and limitations of using BNF, and set up a pilot inoculant plant with packaging and marketing schemes.