Changes in the properties of cultivated gray forest soils after their abandoning

Changes in the physical, physicochemical, and biological properties of cultivated gray forest soils after their abandoning and overgrowing with meadow and forest vegetation for 8–10 years are clearly seen in the upper part of the former plow layer. The organic matter content and the content of available forms of phosphorus and potassium increase; a significant increase in the root biomass and in the soil biological activity is observed. Changes in the physical properties—an increase in the degree of soil aggregation and a decrease in the bulk density values—are seen in the upper and middle parts of the former plow layer. The biological factor is the major factor of transformation of formerly cultivated gray forest soils upon their abandoning and overgrowing with meadow and forest vegetation. At the same time, a significant role in the improvement of the structural state of the soils belongs to the physical shrink-swell and freezing-thawing processes.