Enzymatic activity of soil microbiota under different fertilizer systems

Abstract

Soil enzymes are mostly synthesized by microorganisms and play an essential role in metabolism since they are biological catalysts for the transformation of organic residues. The activity of enzymes is affected by many factors, for instance, the number and activity of soil microbiota, the physicochemical properties of soil, organic matter content, weather conditions during the growing season, incorporation of organic residues into the soil, and the farming system. Among the various groups of soil enzymes, catalase and proteases deserve special attention. Catalase activity associated with the content of organic carbon in the soil is used as an indicator of soil fertility. Soil proteases play a significant role in nitrogen mineralization. The goal of our study was to compare soil enzyme activity in short crop rotation under different fertilizer systems. Methods. Soil catalase activity was determined by gasometrical method. Soil protease activity was determined by the Romeiko method. Results. |Soil protease activity increased from the beginning to the end of vegetation, with the maximum catalase activity being observed approximately in the middle of the growing season of the studied crops. Protease and catalase activities of rhizosphere soils were higher than those of the bulk soil, probably due to higher activity of root-associated microbial communities. The highest indicators of enzymatic activity were recorded under biological fertilizer system. Conclusion. The biological system of crops fertilization of a short crop rotation ensures optimal conditions for the course of enzymatic processes, which, obviously, is a consequence of the activation of soil microbial communities