Influence of Bacillus subtilis on the physiological state of wheat and the microbial community of the soil under different rates of nitrogen fertilizers

The effects of inoculation with bacteria Bacillus subtilis strain No. 2 (hereinafter, B. subtilis 2) and of the physical properties of the soil on the physiological state of wheat (Triticum aestivum L.) plants and the soil microbial community under different rates of nitrogen fertilizers are studied. In the field, the physiological state of wheat was evaluated using the optical vegetation index. It was found that (1) the impact of B. subtilis 2 on plants decreases with an increase in the rate of fertilizers and soil bulk density, (2) the inoculation of wheat with bacteria enhances the resistance of the plant-microbial system to the adverse impact of high rates of nitrogen fertilizers due to the rearrangement of bacteria in rhizosphere ecological niches, and (3) the highest agronomic efficiency of nitrogen fertilizers is observed in wheat inoculation with B. subtilis 2 at the rate of nitrogen fertilization of 120 kg/ha.