INFLUENCE OF DIFFERENT SYSTEMS OF CROP FARMING ON ECOLOGICAL AND TROPHIC GROUPINGS OF MICROORGANISMS OF TYPICAL CHORNOZEM IN THE CONDITIONS OF THE LEFT-BANK FOREST STEPPE OF UKRAINE

Abstract

Objective. To establish the influence of different crop farming systems on the parameters of the number of representatives of ecological and trophic groups of microorganisms in typical chernozem. Methods. Comparative-profile-genetic, microbiological, statistical. Results. The upper 0–10- centimetre layer of soil (the number of microorganisms decreases with depth and the predominance of microbiological activity in the 10–20-centimetre layer is possible only in dry periods) is characterised by the highest microbiological activity. The microbiocenosis undergoes the greatest transformations in the conditions of intensive system of crop farming upon mixing and turn of a layer. This is expressed in a significant decrease in microbiological activity in the 0–10-centimetre layer and vice versa — an increase in the layers of 10–20 and 20–30 cm. Agrogenic soils have higher parameters of total microbiological activity compared to the fallow area. The most positive influence on biogenesity was reported in the variants of the organic system of crop farming, especially with the use of green manures. The data on the directions of development of soil biological processes of the studied variants by the analysis of oligotrophic coefficients, mineralization-immobilization and mobilization of nitrogen stock are provided. Mathematical analysis of the data showed a significant influence of the depth of sampling on the number of all studied microorganisms, while the crop farming system significantly affected the number of microscopic fungi, actinomycetes and amylolytic microbiota. Conclusion. Agrogenic use of chernozems reduces the number of microscopic fungi. In the variants of organic crop farming, a significant increase in the number of actinomycetes and amylolytic microbiota was reported. Under the intensive system of crop farming, there is a decreased number of representatives of all studied ecological and trophic groups of microorganisms. And vice verse, variants of the organic crop farming system, especially under the use of green manure, have a higher number of most functional groups of microorganisms. Cultivated soils are characterized by a higher coefficient of mineralization and immobilization compared to fallow.