Dynamics of phytotoxicity of soil under different fertilizer systems

Soil microorganisms, root system of plants, organic residues and fertilizers contribute to the release of physiologically active substances and their accumulation in the root part of the soil. Accordingly, soil phytotoxicity affects the growth and development of agricultural plants. Therefore, the aim of the work was to evaluate the phytotoxic properties of the soil under different fertilization systems for winter wheat, soybeans, corn and sugar beets. Analysis of soil phytotoxicity was performed according to the method of A.M. Grodzinsky. At the beginning of the soybean growing season, the greatest phytotoxic activity was observed on the biological fertilizer system, which involved the use of corn residues (8-12 t/ha) + Biohumus "ECOCHUDO" 200 kg/ha, which is most likely caused by slow soil neutralization. microbiota of allelopathic secretions of cereals. It was established that the application of ecological and biological fertilization systems for winter wheat yielded minimal values of soil phytotoxicity and at the end of the growing season was 4.39-3.65 UCO, the lowest in the experiment. Under the ecological system of fertilizer (crop residues of wheat (8-10 t/ha) + N90P60K90) and especially biological (crop residues of wheat (8-10 t/ha) + Biohumus "ECOCHUDO" 1000 kg/ha) indicators of phytotoxic activity soil in the phase of 2-4 leaves in sugar beets were the highest, but during the subsequent growing season the values decreased by 34-47%. Due to the application of the ecological system of corn fertilization (crop residues of sugar beets (30-40 t/ha) + N15Р30К30) the phytotoxicity of the soil during the growing season decreased by 37.9%. At the same time, the maximum reduction occurred by 66.8% in the biological system of fertilizers (crop residues of sugar beets (30-40 t/ha) + Biohumus "ECOCHUDO" 750 kg/ha). Accordingly, the conditions of the soil environment under the biological system of agriculture were the most favorable for development: soybeans, wheat, sugar beets, corn.