4 cells per gram of soil sample was estimated whereas this population was 5.8 x 10 5 in Nkoemvone. Overall, population sizes of rhizobia using the three varieties were higher in Nkoemvone soil than in Nkometou soil. The cowpea variety 58-77 seemed to have high nitrogen fixation potentials as it formed nodules more than the two other varieties in both soils. The levels of Bradyrhizobia populations observed in the two sites were adequate to give satisfactory results on nodulation and nitrogen fixation. This suggests that cowpea production in southern Cameroon does not require inoculation.

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