SOIL COVER AND AGROCHEMICAL PROPERTIES OF THE SOILS OF THE MAIN REMEDY OF THE RAVINE PROTECTION SYSTEM "FAN OF THE CITY CHEBOKSARY"
In July-August 2017soil-agrochemical studies were conducted on the territory of the “Veerny (Fan)” ravine system located in the “New city” district of Cheboksary. The territory of the ravine system is located on the steep right-bank slope of the Volga River (a watershed slope), where the height difference is more than 88 m. The slopes and the ravine slopes are mostly extremely steep and steep. The soil-forming rocks of the ravine slopes in its upper part are loess-like Pleistocene carbonate loams, in the middle - Middle Jurassic sediments of the Callovian layer (gray and greenish-gray clays), in the lower part - Upper Permian deposits (sandy-colored aleurites with red-brown clay,)and diluvium as well. The soils of the studied gully system are of the type of thin, shallow and underdeveloped gray forest, formed on landslides, scree and slopes. Low-power light forest soils with the humus horizon (A1 + A1A2) with thickness of less than 20 cm are found near the ravine edge and on flat elevations in its valley. Small forest soils occur on less steep ravine slopes (31-45 degrees) and have an incompletely developed profile with capacity less than 50 cm, characterized by a complete set of genetic horizons, characteristic of gray forest, but poorly developed soils. Underdeveloped forest soils have a primitive soil profile characteristic of the first stages of soil formation: a thin humus horizon, often 3-5 cm thick, lies on the surface of the forest floor. Below the soil-forming rock "C" lies. In microgloves of a ravine system there are thin and shallow forest gley soils. As a result of the research, a soil map was drawn up and the agrochemical properties of the soils of the main ravine of the “Fan” ravine system were studied. The humus content in the soils of the ravine slopes is 1-4%; mobile phosphorus and exchangeable potassium - increased and high, heavy metals and radionuclides - within the MPC (maximum permissible concentrations). Hydrolytic acidity is low - 1.0-1.9 mg-eq / 100 g, the amount of exchange bases varies from 8.6 to 14.6 mg-eq / 100 g. The quality of the current state of the soil complies with the sanitary-epidemiological requirements. The research results clearly indicate the ecological well-being of the territory of the “Fan” ravine system.