Biopreparations as a method to biologize the agrocoenosis of the pear nursery

In the agrocenosis of a fruit nursery, a significant amount of nutrients is consumed. It requires the introduction of large doses of mineral fertilizers, which leads to environmental pollution. The use of biopreparations (BP) can increase the productivity of agrocenosis, soil fertility and its biological activity while reducing the chemical load. The aim was to study the influence of BP on the state and productivity of the agrocenosis, as well as elements of fertility and biological activity of the soil. The article presents data from field experiments on the use of biopreparations Azotobacterin-Agro (AB) and Microbiocom-Agro (MBC) in the pear nursery. BP was applied to the root system of quince rootstocks of VA 29 and KA 53 before planting; inoculation was carried out by the varieties of Tavricheskaya and Maria. The repetition of the experiment was threefold. The soil was the southern carbonate chernozem of the Crimea. In the soil (depth 0–40 cm), the content of humus, mobile forms of nutrients and the number of seven ecological and trophic groups of microorganisms were determined. It was found that BP had little effect on the survival rate of rootstocks, but they increased the survival rate and winter hardiness of the graft by 6–11 % and the growth rates of seedlings by 14–26%. The use of AB led to an increase in the yield of pear seedlings on the Tavricheskaya variety by 6–10 %, on the Maria variety by 10–21 %, depending on the rootstock. Under the influence of BP, the humus content remained stable or increased by 0.03–0.20 %. On a more intensive rootstock of KA 53, there was a depletion of the soil with nutrients, especially on the Maria variety (growing stronger). In the rhizosphere of plants grafted on VA 29, BP contributed to an increase in the content of nutrients by 5–24 % to a greater extent under the action of AB. In this case, there was an increase in the number of bacteria of the main ecological and trophic groups by 20–56 %, more significantly of autochthonous microbiota. An increase in the values of ecological and trophic indices when using AB on the Maria variety indicates an improvement in nitrogen nutrition, accumulation of humus, as well as stabilization of agrocenosis.