Assessment of meadow soil resistance of the Azov Sea Region to pollution with heavy metals and oil

摘要

Since meadow soils are little used in agriculture and are often distant from chemical contamination sites, there are few studies on the effect of chemical pollution on the state of these soils. At the same time, due to the increase in traffic flow to theCrimea through the Kerch Strait, the risk of contamination of meadow soils of the Azov Sea Region with heavy metals, oil and oil products is growing. The study assesses the resistance of meadow soils of the Azov Sea Region to pollution by oil, chrome, copper, nickel and lead by biological indicators. As a rule, upon contamination of meadow soils of the Azov Sea Region, there has been observed a significant decrease in the total bacterial count, in the activity of catalase and dehydrogenase, cellulolytic activity, in abundance of the Azotobacter genus bacteria, and in the radish germination intensity. The degree of reduction depended on the nature of the pollutant and its concentration in the soil. As a rule, there has been observed the direct relationship between the concentration of the pollutant and the degree of deterioration of the soil properties under study. According to the degree of ecotoxicity the HMs (heavy metals) form the following series for meadow soils of the Azov Sea Region: Cr>Cu>Ni>Pb. A comparative assessment of the resistance of the Azov Sea Region soils has shown that meadow soils are less resistant than chernozems, but are more resistant than sor and marsh solonchaks, meadow-marsh and rice soils. The quantitative guidelines have been defined for the development of regional standards for the maximum allowable content of chromium, copper, lead, nickel and oil in meadow soils of the Azov Sea Region, determined by the violation of the ecological functions of soils.