Alterations in the absorption capacity of soils depending on the elements of the relief of the ravine catchments of the Central Black Earth Region

Abstract

The article studies the features of the composition of the soil adsorption complex (SAC) with regard to the erosion and accumulation processes. It demonstrates that the adsorption capacity of soils differs depending on the relief of the ravine catchments. The dependency between the amount of absorbed soil bases and the content of silt fraction was determined. The article studies the composition of the soil adsorption complex depending on the relief of the ravine catchment. The purpose of the study was to determine the dependence of the SAC on the degree of development and nature of water erosion and accumulation. To achieve this goal, the following tasks were performed: conducting a soil-erosion survey of a ravine catchment area; determining the physical and physicochemical properties of soils using GOST and generally accepted methods; performing a comparative analysis of the soil absorption properties depending on the elements of the relief of the ravine catchment. The relevance of the study of the absorption properties of soils subject to washout and deposition is determined by the high degree of erosion of the territory. The object of the study was the soil of the catchment area of the «Log Repny» ravine. According to the soil-erosion zoning of the Voronezh Region, the object of the study is located in the Semiluksky-Nizhnedevitsk District. The entire soil profile of the watershed slopes and the bank of the ravine was deteriorated by silt fraction due to the influence of soil erosion and denudation. At the bottom of the ravine, the upper part of the soil profile was enriched with silt fraction, which was caused by the accumulation of soil material washed away from the slopes above. The absorption capacity of soils of various elements of the relief of the «Log Repny» catchment area can be characterized by the amount of the absorbed bases. The largest amount of absorbed bases was observed on the inland plateau (15.73 mmol/100 g of soil). On the bank of the ravine, the amount of absorbed bases was 2.5 times lower, which is accounted for by the denudation process. At the bottom of the ravine, in the zone of primary accumulation of soil material washed off the slopes, the amount of absorbed bases was 1.4 times lower than on the watershed. This happens due to the different content of silt fraction in these soils. Thus, in the soils of watersheds, the silt fraction was 24.8%, on the bank of the ravine its content was 2.5 times lower, and at the bottom of the ravine it grew back to 22.4%. The dependence of the amount of absorbed soil bases on the redistribution of silt fraction under the influence of soil erosion and accumulation was established.