Soil Enzyme Activity in Natural and Plowed Catenas as Parameters of Physiological State of Microbial Communities.

The study of soil microbial biomass and enzymatic activity of natural and anthropogenically transformed ecosystems was carried out. The catenas of virgin luvisols and chernozems of the Belogorye Natural Reserve and the catenas of arable soils were studied under similar geomorphological and lithological conditions. The activities of enzymes involved in the cycles of carbon (β-glucosidase and xylosidase), nitrogen (chitinase), and phosphorus (acid and alkaline phosphatase) was studied. It has been established that a decrease in soil microbial biomass as a result of plowing is not accompanied by an equivalent decrease in the enzymatic activity of the soil. Differences in the enzymatic activity of different soils types were revealed, which indicates differences in the structure of the microbial community and the type of phytocenoses. Patterns of changes in the enzymatic activity of soils in watershed areas, in the transit and accumulative parts of catenas, have been established. The values of specific activities of enzymes (enzymatic activities per unit of microbial biomass) were calculated. The obtained patterns of changes in the specific enzymatic activity of arable soils indicate that, despite the loss of organic matter and a decrease in microbial biomass as a result of plowing, the physiological efficiency of the microbial community of agrochernozem is higher than in virgin soil. High specific enzymatic activity in arable soils is associated with higher rate of enzyme production by soil microorganisms due to land use changes. [ABSTRACT FROM AUTHOR]