BIOLOGICAL PROPERTIES OF SOILS OF VOLGA DELTA HILLY LANDSCAPES

Firsova Ksenia Strgeevna  -  Master's degree in Soil Science, Federal State Budgetary Educational Institution of Higher Education “Astrakhan State University name after V.N. Tatishchev”, Russia, 414000, Astrakhan, Shaumyana Sq., 1,

Yakovleva Lyudmila V.  -  D. Sc. (Biology), Associate Professor, Head of the Department of biotechnology, aquaculture, soil science and land management, Federal State Budgetary Educational Institution of Higher Education “Astrakhan State University name after V.N. Tatishchev”, Russia, 414000, Astrakhan, Shaumyana Sq., 1, yakovleva_lyudmi@mail.ru

The article presents the results of a study of the biological properties of brown arid soils of Baer knolls with varying degrees of degradation in the central part of the Volga River Delta. Physicochemical parameters determining soil biological activity (soil density, field moisture, soil reaction, and humus content) were analyzed. It was established that the profile of the studied soils is characterized by a slightly alkaline to alkaline reaction, a thin humus horizon in which the humus content does not exceed 0.9% and exhibits pronounced differentiation in density and the presence of carbonate, salt, and gypsum inclusions. Maximum values of catalase activity (up to 5.25 ml O2/g) were recorded at the base of the Baer knolls. The alkaline environment of the soil solution determines the bacterial type of the microbial community. At the tops of the knolls, biological activity is suppressed due to deflation, intense mineralization, and high alkalinity.

Key words: brown arid soils, enzymatic activity, microbiota, Volga Delta, environmental monitoring.