Influence of Anthropogenic Impact on Alteration in the Alluvial Soil Fertility Indicators

The article presents studies on establishing the influence of anthropogenic impacts on alluvial soils of agricultural lands. To solve the problem set, tasks were determined to estimate the degree of damage caused to soils of agricultural lands as a result of the soil humus layer loss or closure. These tasks included establishing the degree of alteration in soil fertility indicators for agricultural lands in regard to pH volume; organic matter content; degree of provision with K2O and P2O5 accessible forms as a result of violating technology of the damaged land stripping and reclamation. Nature of changes in granulometric (grain) and micro-aggregate soil composition is demonstrated. Study objects included agricultural land territories with soil samples of alluvial granular soil taken at the depth of 0-5 cm and 5-20 cm. Necessity is demonstrated to study in detail the agroecological assessment of land use systems and the development of differentiated measures ensuring reproduction of soil fertility, crop growth and territory ecological sustainability. Negative processes are manifested to a varying degree on agricultural land in most administrative regions of Russia including agricultural land in the Orel Region, which requires creation of the ecologically sustainable land use system. Since transformation of compounds entering the ecological system primarily occurs in the soil, which acts as a filter and as the factor of transformation and accumulation of the entering substances, agrobiological features of soil composition and properties make it extremely sensitive to anthropogenic impact. As a result of scientific research, it was revealed that the studied area experienced a decrease in soil fertility main indicators of the alluvial soils and destruction (deterioration) of the fertile soil layer as a result of exposure to anthropogenic influence. Rates of decrease in the organic matter content in soil layer as a result of the soil humus layer damage are shown. Significant fluctuations in the amount of exchangeable potassium in the soils of anthropogenically damaged agricultural lands are established. Degree of decrease in the amount of available phosphorus in soils without humus layer is revealed. Significant alteration in the granulometric (grain) composition of the damaged land soil is proved.