AgriBacter — a biological preparation containing the active substance Bradyrhizobium elkanii in the form of strains U 1301 and U 1302. The titre of viable cells is not less than 1?1010 CFU/ml of the preparation. The preparation is intended for use in agriculture, particularly in soybean cultivation. Use of the biological preparation enhances plant productivity due to interaction of microorganisms with plant root systems. The biological preparation is environmentally safe and does not cause negative effects on soil and water resources. The preparation can be applied within integrated agronomic practices to ensure stable yields and reduce dependence on chemical fertilizers.