Influence of Chemical Meliorants on Microbiological Activity of Chernozem-Meadow Soils

The study was conducted in the Voronezh FASC “Kamennaya Steppe” in 2020–2022. The assessment of the state of the structure of microbial cenosis in meadow soils with the use of various chemical meliorants is given. Options for reclamation included the introduction of gypsum and defecate at a dose of 5 t/ha and a combination of their half doses. The number of ecological and trophic groups of microorganisms was determined by seeding on solid nutrient media. Accounting for organisms assimilating organic forms of nitrogen – by sowing on meat-peptone agar (MPA), accounting for organisms assimilating mineral forms of nitrogen – by sowing on starch-ammonium medium (SAM), accounting for organisms mineralizing humus – by sowing on nitrate agar, accounting for fungi – on Chapek medium, accounting for the amount of nitrogen – on soil plates, accounting for nitrifiers – on hungry agar, accounting for organisms that decompose fiber – on Vinogradsky’s medium. As a result of chemical reclamation of meadow soils with the use of gypsum and defecate as meliorants, patterns of changes in the activity of soil microorganisms were established. It was possible to identify a fairly clear dependence of the increase in the number of microorganisms that utilize organic forms of nitrogen on the use of meliorants in meadow soil of a hollow-shaped depression. Mineralization processes of organic matter were maximally expressed in meadow-chernozem soil on a plain rise when gypsum was used as a meliorant at a dose of 5 t/ha, while the use of gypsum and defecate at a dose of 2.5 + 2.5 t/ha had a greater effect on the content of nitrifiers in this soil. In the chernozem-meadow soil of a hollow-like decrease, the use of defecate at a dose of 5 t/ha led to an increase in the content of actinomycetes. In the chernozem-meadow soil of the plain depression, the use of all meliorants had an impact on the increase in the number of humus mineralizers, fungi, as well as nitrifiers compared with the control. It was not possible to identify any significant pattern associated with the use of meliorants on these soils for the maintenance of azotobacter colonies. In soils with different degrees of soil moisture, the use of meliorants had an ambiguous effect on the number of cellulolytics: an increase in soil hydromorphism in combination with the use of defecate at a dose of 5 t/ha led to a maximum increase in cellular microorganisms in the chernozem-meadow soil of a hollow-like decrease.