The vast majority of modern chemical pesticides eliminate the problem of the spread of diseases and pests, but lead to the deterioration of the ecological condition of agrocenoses. However, the use of biological products allows not only to obtain high-quality, environmentally friendly agricultural products, but also to maintain ecological balance in the agrocenosis. We studied the biological activity of the soil of the root zone of maize plants during pre-sowing seed treatment with a complex of biocompositions № 1 and № 2. The study included control (without seed treatment), pre-sowing seed treatment with a mixture of chemicals and pre-sowing seed treatment with microorganisms дослідження 1 № used maize hybrids of Ukrainian selection Khorol SV and Vizir. Soil sampling and microbiological studies were performed by conventional methods.Pre-sowing treatment of corn seeds with a complex of compositions of microorganisms № 1 and № 2 reduced the number of micromycetes by 1.8–2.2 times, but the total biological activity of the soil was at the level of control variants. In addition, in the variants with the investigated complex of compositions of microorganisms № 1 and № 2, the level of antifungal activity increased more than 4‒7 times relative to the control, and 1.5 times relative to the variants where chemicals were used. Thus, in the conditions of temporary field studies it is proved that bioagents of compositions № 1 and № 2, introducing into the root zone of maize plants by pre-sowing seed treatment, initiate changes in the functioning of the microbiocenosis and protect plants during their growing season. Thus, the complex of compositions of microorganisms № 1 and № 2 is promising for the creation of a modern, complex biological product, which in the future will allow to obtain environmentally friendly agricultural products
carbon dioxide emission, biomass of microorganisms, antifungal activity, phytotoxicity, number of micromycetes, maize, biological products, microorganisms, biofungicide