IDENTIFICATION OF FACTORS DETERMINING MICROBIOLOGICAL ACTIVITY OF BIOCENOSIS

Abstract

It is important to establish methods and approaches that ensure phytosanitary recovery of agrocenoses. Phytosanitary recovery of agroecosystems of fodder crops is possible by pre-treatment of seeds, application of mineral and organomineral fertilizers in order to increase resistance of plants to diseases and soil suppressiveness to phytopathogens. The aim of the research was to establish the influence of mineral, organomineral fertilizers and preparations for pre-treatment of seeds on the microbiological activity and suppressiveness of the soil in the rhizosphere of spring barley, peas and spring rapeseed. Field and laboratory studies were carried out on the pilot field and in the laboratories of the FSBOU VO Kurgan GSHA from 2001-2020. Studies have found that the introduction of mineral fertilizers into the soil changed the number of the main ecological-trophic groups of microorganisms in the rhizosphere of plants (bacteria that absorb organic and mineral forms of nitrogen, nitrifiers, cellulose-decomposing and denitrifying bacteria, oligonitrophilic and nitrogen-fixing bacteria). When introducing mineral fertilizers, an increase in cellulosic, proteolytic, catalase, invertase and total biological activity of the soil was noted. When introducing mineral fertilizers in the rhizosphere of spring barley, soil suppressiveness increased to 56.7-63.2% in relation to root rot pathogens. There was a negative correlation between soil suppression and the development of root rot of spring barley, which was -0.93, the regression equation was as follows: y = 47.08-0.05x. Soil suppressiveness against pea fusariosis pathogens increased with the introduction of mineral fertilizers by 32.2-46.0%. The correlation between soil suppression, development of pea fusariosis was -0.90, respectively, the regression equations were as follows: y = 54.11-0.05x. Soil suppressiveness against root rot pathogens and rapeseed fusariosis increased to 43.7-48.4% or 2.2-2.3 times compared with control.