Search Results       Your search for [subject]Nitrogen fixation -- Biological nitrogen fixation -- Congresses returned 1 record.           Biological nitrogen fixation in farming systems of the tropics. by Ayanaba, A., ed.; Chichester: Wiley, 1977. Subject: Agriculture -- Cropping systems -- Tropics -- Congresses; Farming systems -- Tropics -- Congresses; Nitrogen fixation -- Biological nitrogen fixation -- Congresses.          Add to Book Cart Relevance: 46.40%