Determination of Rhizobial Population of Soils from North Western Nigeria for Biological Nitrogen Fixation on Soybeans

Abstract

A study was conducted to estimate the rhizobial population of soils for biological nitrogen fixation on soybeans (Glycine max) by the Most Probable Number (MPN) technique. Soils were collected from seven locations namely; Albasu, Bichi, Garko, Gaya (Sudan savanna), Giwa, Soba and Z/kataf (northern guinea savanna). The result showed that Garko has the least MPN rhizobia/g (0.61x10) and Z/kataf has the highest MPN rhizobia/g (7.65x10). The soils collected from northern guinea savanna have the highest MPN rhizobia/g compared to the soil collected from