Seasonal changes in the moisture of dark gray podzolized soil in conditions of different exposure of the relief of the Kharkov region

Abstract

Goal. To assess the seasonal dynamics of soil moisture on the relief elements of the slope system of the beam — the north-western and south-eastern slopes, its bottom, and on the adjacent plain territory in the conditions of the Forest-Steppe zone. Methods. Field — for soil sampling; instrumental — for measuring soil temperature; laboratory — to determine the moisture content of the soil; office calculation of the amount of precipitation using a measuring cup; abstract — to formulate theoretical conclusions; mathematical and statistical — for processing and analysis of the data received. Results. The study was conducted (in the spring of 2023 — summer 2025) within the boundaries of the Forest-Steppe zone in the Kharkiv region near the village Korotych on 4 landforms formed as a result of the action of river and beam systems. The soil on the slopes and plane was dark-gray podzolized, in the beam — meadow podzolized. It was proved that the seasonal dynamics of soil moisture were determined by weather conditions and the type of relief, forming a classic cycle of winter-spring accumulation, summer drying, and autumn replenishment, but with different quantitative values; the difference was 20–55 mm of productive moisture. Soils of the north-western slopes stably accumulated moisture in spring and autumn, partially preserving it in summer. The rapid drying of the upper soil layers on the south-eastern slopes was confirmed due to increased insolation and heating, which led to a contrast in the moisture content along the profile. It was found that the soils of the plain and the bottom of the beam had significant profile heterogeneity with low moisture in the summer during the period of extreme drought. Conclusions. The location of soils in the relief determines their differentiation by humidity parameters. The maximum expression of these differences is characteristic of the 2nd part of the warm period, the range of productive moisture reaches 55 mm. The soils of the north-western exposition are distinguished by high moisture content in seasons, and the soils of the south-eastern exposition are reduced. The podzolized soils on the plain and in the bottom of the beam are characterized by an unstable water regime.