INFLUENCE OF STRAINS ASSOCIATED WITH TRITICUM AESTIVUM L. ON MICROBIOCENOSIS IN THE RHIZOSPHERE OF WINTER WHEAT OF CHERNOZEM SOUTHERN

Abstract

Pre-sowing inoculation with strains of associative bacteria is one of the promising methods for increasing the productivity of agricultural crops. These microorganisms are able to stimulate the growth processes of plants, improve their mineral nutrition, increase phytoimmunity and resistance to adverse factors. The aim of the research is to study the influence of strains with a high associative potential to Triticum aestivum L. on the microbiocenosis in the rhizosphere of soft wheat of several varieties grown on chernozem southern. The studies were carried out in 2018–2020 using three varieties – ‘Ermak’, ‘Bagheera’, ‘Lydia’. The experiments were laid on plots (accounting area – 25 m2) in systematic design, replicated four times. The climate of the study area is characterized as arid (steppe). Inoculation was carried out before wheat seeds sowing; option without treatment served as a control. Sampling was carried out in the most active phase – flowering (in May 2019 and 2020). In the course of the research, we found that changes in the number of microorganisms of various ecological-trophic groups of chernozem southern in the rhizosphere of wheat occur under the influence of bacterial strains associative to T. aestivum. Wheat variety ‘Bagheera’ was found to be the most responsive to seed bacterization; the average yield increase over two years of research was in the range of 0.2-0.4 t/ha or 5-10%. Calculation of coefficients and indices indicating the direction of mineralization processes in the soil made it possible to establish that inoculation promotes their activation. The results of the correlation analysis based on two-year data obtained after studying three varieties of winter wheat showed that the number of bacteria of the genus Azotobacter has the greatest influence on the yield – the correlation index is 0.81 at p <0.05.