Ecological features of urease activity distribution in technogenically altered soils of the Nikopol manganese ore basin

Abstract

The challenge of degradation of natural ecosystems because of human activity is considered by the world community to the most serious problems facing mankind. As a result of mineral extraction, man-made landscapes and environmentally ruined areas replace natural habitats and agroecosystems; a whole spectrum of man-made processes are typical for such landscapes, which leads to a decrease in species richness and biological diversity within such areas. Degraded territories formed in the process of coal mining are often partially restored through remediation measures. During the implementation of the technical stage of remediation, substrates with different potential fertility having different environmental properties and quality are used. Specific features of distribution total, available nitrogen concentrations and levels of urease enzymatic activity at the layers of artificial soil, sod-lithogenic soils onto gray-green and red-brown clays and on loess-like loams in the Nikopol manganese ore basin are established. It is presented general assessment of technosol status by concentration of general easily hydrolysed nitrogen enzyme activity of urease and this enzyme enriches the soil with mineral nitrogen in the process of mineralization of organic substances.  The level of activity of urease,  investigated soils, determines the intensity of the direction of biochemical processes that affect soil fertility.High correlation between concentrations of soluble nitrogen and urease activity values by layers of artificial soil (r = 0.81), sod-lithogenic soils onto gray-green (r = 0.98), red-brown clays (r = 0.72) and onto loess-like loam (r = 0.85) were found. Tendency of decreasing hydrolytic enzyme activity, urease, with depth in all types of artificial soil studied was established. It has been established that biochemical diagnostics of technozem processes beyond the level of activity of the hydrolytic enzyme urease makes it possible to estimate the direction of changes at the layers of artificial soil, sod-lithogenic soils onto gray-green and red-brown clays and on loess-like loams. The recultivated soil has some what lower fertility and greater salimity at the lower horizons, but is capable of performing ecological functions and can not only be used for economic purposes, but also perform ecological functions.