Dynamics of the Typical Chernozems’ Properties in the Streletskaya Steppe National Park under the Influence of Long-Term Agrogenic Impact

Resumo

Typical chernozems of protected areas are characterized by a high humus content, a stable absorbing complex, and favorable agrochemical properties and demonstrate high number and activity of different groups of microorganisms, which is indicative of deep mineralization of plant residues and the storage of biogenic elements in microbial biomass. In the longstanding fallows, the structure of the microbial community is disturbed: the proportion of the oligotrophic groups, which are able to transform humic substances, increases. The rate of cellulose decomposition slows down, phytotoxicity increases, and dehumification develops. In the rotation, negative dynamic of these indicators is smoothed.