Assessment of the state of soils of uncultivated agricultural lands by indicators of enzymatic activity, humus and heavy metals

Studies were conducted to determine such indicators as humus, heavy metals, and enzymatic activity in the soils of uncultivated farmlands of the Vladimir region located in the Klyazma river basin. In the course of field research in 2018, soil samples were selected at 13 points representing various landscape areas belonging to the Klyazma river basin. According to the results of research, a positive relationship between the activity of soil enzymes and the content of humus was established. In the soils of uncultivated farmland, where there is a high concentration of soil enzymes, a high percentage of humus was found – from 2.88% to 3.96%. The dependence between the indicators of activity of soil enzymes and anthropogenic impact was revealed. Thus, the transition from deposits to the meadow, i.e. reduce anthropogenic impact on the soil, there is a sharp increase in the activity of soil invertase, catalase and dehydrogenase, an active process of humification of soil. The detected concentrations of heavy metals in soil samples of uncultivated farmland do not exceed the standards set for the approximate permissible concentrations, but their quantitative content has increased significantly over the past decade, their accumulation occurs and there is a potential danger in the case of secondary input of these soils into agricultural use.