Evaluation of Phytotoxicity of Common Chernozem in the Application of <i>Bacillus</i> sp. and Biochar for Stimulation of Decomposition of Winter Wheat Harvest Residues (<i>Triticum aestivum</i> L.)

Stable functioning of agricultural lands is impossible without maintaining soil fertility. However, there are often a lot of crop residues in the fields, which decompose for a long time and turn into available organic matter. To increase the rate of decomposition of crop residues of grain crops (wheat, barley and others), it is necessary to introduce biostimulants. Biostimulants are a variety of substances that stimulate the decomposition of organic substances and have a beneficial effect on the soil microbiota. The article examines the influence of Bacillus sp. on the processes of decomposition of crop residues of wheat both independently and together with biochar. The aim of the study was to evaluate the phytotoxicity of ordinary chernozem during the decomposition of crop residues of winter wheat under the influence of Bacillus sp. and biochar. To assess the ecological state of the soil, the following research methods were used: assessment of the rate of decomposition of cellulose (determination of cellulolytic activity), assessment of the ecological state of the soil (intensity of CO2 emissions, changes in the intensity of initial growth and development of winter barley (Hordeum vulgare L.)). Introduction of Bacillus sp. × 100 and the joint use of biochar and Bacillus sp. it stimulated the decomposition of cellulose up to 14–15% of the background content. Inoculation of Bacillus sp. on the biochar, it was effective already at the recommended dose both for the decomposition of the cellulose web and for restoring the ecological state of the soil, demonstrating a synergistic effect. The results obtained should be used in carrying out measures to increase soil fertility of agricultural lands and environmental monitoring of soil conditions.