THE INFLUENCE OF AGROTECHNICAL MEASURES AND LONG-TERM IRRIGATION ON THE CHARACTERISTICS OF DARK CHESTNUT SOILS

Abstract

Agrotechnical measures and irrigation have a significant impact on the natural processes of soil formation and their characteristics. The intensity of anthropogenic impact is a key factor determining the scale of these transformations. The purpose of the study is to evaluate the transformation of the properties of dark chestnut soil as a result of agricultural development and long-term irrigation. The study was conducted on three types of sites with different moisture regimes: virgin, irrigated for more than 20 years, and non-irrigated. Irrigation in the study area was carried out by sprinkling using a wide-scope sprinkler machine. The soil in all study areas is dark chestnut, slightly saline, and medium loamy. The groundwater level in all areas was more than 4 meters from the surface. Chemical analysis of irrigation water showed the presence of calcium bicarbonate salts. For a detailed study of the morphology and physico-chemical properties of soils, soil sections were laid. The results of the study demonstrated that irrigation of dark chestnut soils contributes to the formation of a more powerful soil profile compared to areas that do not receive artificial moisture. Irrigation with bicarbonate-based water promotes salinization and has a positive effect on soil characteristics. Density analysis revealed significant differences between soil horizons. In natural conditions, the equilibrium density of the soil increases from 0.9 g/cm3 to 1.18 g/cm3 at a depth of 45 cm. In the non-irrigated, cultivated area, the density in the upper layer increased significantly to 0.92 g/cm3. In the irrigated area, the density in the same layer reached 1.14 g/cm3. In the 10-30 cm layer, the density in the non-watered area increased to 1.21 g/cm3 due to treatment, and in the third (with irrigation) to 1.39 g/cm3. Intensive farming and plowing led to a significant decrease in the humus content: in the 0-25 cm layer from 4.9% to 2.6-2.8%, and in the 25-50 cm layer from 2.95% to 1.4-1.8%. Irrigation had a positive effect on the humus content. The additional moisture stimulates the supply of organic substances, contributing to the accumulation of humus. If the irrigation water is enriched with calcium, the process of humus formation is accelerated, and the mobility of humus decreases. The optimal choice of agrotechnical techniques and irrigation technologies is a key factor in minimizing the ecological footprint of agricultural activities.