Effect of Bradyrhizobium japonicum and its strains on the growth performance, nodulations and nutrient uptake of soybean in mycorrhizal soil.

Interactions between vesicular arbuscular(VA) mycorrhizal and Rhizobium strain were examined in soybean (Glycine max).A synergistic effects was notice on plant biomass, colonization, spore formation and nodulation in soybean when Bradyrrhizobium japonicum was also used along with VAM inoculations. Their combined impact was significantly greater than the individual. However, G. fasciculatum in combination with rhizobia was found more effective than G. mosseae. The VAM fungi- and Rhizobium combined also supported optimum uptake of three nutrients (NPK) by soybean. Though phosphorus uptake was maximum in G. fasciculatum followed by potassium while maximum uptake of nitrogen was supported by G. mosseae over phosphorus and potassium. Out of three B. japonicum strains, strain BRJS-2 was found most virulent and its impact on growth and other parameters of soybean was good, with or without VAM fungi. However, its performance was significantly greater when used with VAM fungi.