Study on the isolation and characterization of rhizobia strains as biofertilizer tools for growth improvement of four grain legumes in Ngaoundéré-Cameroon

Increasing the yield and economical efficiency of grain legumes in the Guinea-Savannah zone of Cameroon is a high researcher priority to assist growers in the rural areas. We report here a two-years study in the production process of fertilizer containing rhizobia for a sustainable production of grain legumes in the region. To address the issue, nodulation and rhizobia strains characterization were assessed at Dang and Wakwa, two soils different in trapping rhizobia partners for groundnut, bambara groundnut, cowpea and soybean. This was a prerequisite step in the determination of the most efficient rhizobia strains for biofertilizer production. Results indicate that all the four grain legumes differently formed nodules in their roots system in the two experimental soils. Cowpea and soybean demonstrated a highly significant (p ≤ 0.001) potential in fixing atmospheric nitrogen through their nodules than groundnut and bambara groundnut. The dry weight of nodules in groundnut and bambara groundnut was significantly lower (0.0001 © 2009 International Formulae Group. All rights reserved. Key words: Grain legumes, nodulation, Rhizobium characterization, Rhizobium biofertilizer.