AGRO-ECOLOGICAL EVALUATION OF DIFFERENT FERTILIZATION SYSTEMS IN THE CONDITIONS OF THE REPUBLIC OF TATARSTAN.

Producers of agricultural plant products are increasingly reporting a decrease in the responsiveness of cultivated plants to the mineral fertilizers applied to the soil. The explanation of this phenomenon can be the shift of limiting factors that determine the yield from the mineral components in the soil to substances of organic and biological origin. In the present work, comparative data are presented on the influence of mineral and organic fertilizer systems on the main biological indicators of the soil - nitrogen transforming groups of microorganisms, total microbial number (TMM), soil respiration. The change in total and mineral nitrogen in the soil is assessed. The novelty of the study is that organic fertilizers are used in amounts comparable to the doses of mineral fertilizers in physical weight - 200 kg per hectare. The application is carried out locally simultaneously with the seeding. As a result of the analysis, it was found that in soil with organic fertilizers under all crops (corn, sunflower, soybeans, sugar beets), ammonificators (20.0-45%) numerically dominate, nitrifiers (30.0-46.7% ), the total microbial number is higher by 24.6-48.3%. The intensity of carbon dioxide emissions (soil respiration) is also higher by 19.0-45.6%. The intensity of biogeochemical processes in the soil and the associated transformations of mineral nutrients, respectively, and the provision of plants with them closely correlates with the number of agronomically valuable groups of microorganisms. The correlation coefficient between the number of ammonifiers and nitrifiers with the total nitrogen content in the soil under all the studied crops on an organic fertilizer system is r = 0.93.