Scientific Journal of KubSAU

The problem of environmental safety of agricultural products and agro-technical measures is very urgent now. Various agrochemicals are widely used in agricultural production: plant protection preparations, fertilizers, stimulants and plant growth regulators, etc. One possible solution of this problem may be a partial replacement of mineral fertilizers by bacterial ones. The aim of our research was to determine the effect of different fertilizers and methods of their application on the quantity of microorganisms in the apple root rhizosphere soil. The research was carried out according to conventional methods. In our experiment, we determined the number of microorganisms in the rhizosphere of the roots of apple trees, nitrogen, phosphorus and potassium in the leaves; hydrolysable nitrogen, available phosphorus and exchangeable potassium in soil and crop yield. The highest yield was obtained by fertigation in our research. Application bacterial fertilizer to the soil ensured yield increase at the level of mineral fertilizer application. Application of fertilizers in general, in the studied application rates provided optimum level of nitrogen, phosphorus and potassium content in the leaves and soil. By use of fertigation and bacterial fertilizers were high and relatively stable numbers of microorganisms in the rhizosphere of the apple trees. The number of microorganisms in the rhizosphere had a positive correlation with yield and the content of nutrients in soil and in leaves

There are given the results of long-term research of different forms of soil nitrogen content and their relationships with the content of total nitrogen in leaves and yield. It was detected a strong positive correlation among them hydrolyzable nitrogen content in the soil and total nitrogen content in the leaves and yield. It is proposed the use of this index for diagnostic of soil nitrogen supply

Soil profiles were made in intensive apple orchard in the agricultural enterprises in Lipetsk and Tambov regions in 2015. Drip irrigation in year rates of 500-550 m3 was carried out since 2010. During the research we determined the soil density, the solid phase density, aggregate composition, particle size distribution, the content of hydrolyzable nitrogen and humus by conventional methods. As a result of drip irrigation can increase dust-like fraction in dark gray forest soil, whereas in chernozems this index did not change significantly. In the black earth soil was noted the process of increasing the proportion of mud fraction due to mineral part chernozem destruction. In both soil types was increased sand content. It was found that drip irrigation improves some of the soil water-physical properties, such as a soil structure coefficient and the content of agronomical valuable aggregates in a layer of 20-40 cm. There was also noted that with increasing soil depth was reduced humus and hydrolyzable nitrogen content. In aggregate analysis, it was found that dark-gray forest soil the amount of water-stable aggregates increased, while meadow chernozem leached soil decreased. Data of the aggregate analysis revealed that in the dark-gray forest soil the amount of water-stable aggregates increased as a result of drip irrigation, while in meadow chernozem leached soil decreased. It recommends by drip irrigation application permanent monitoring of the soil humus content