Hydrophysical soil features under mixed age plant formation in reclaimed agrolandscape

The paper presents the results of long-term monitoring of the water-physical properties of the soils of the reclaimed agrolandscape of the finite-moraine ridge typical of the conditions of the Non-Black Earth Zone of Russia. The studies were conducted from 1997 to 2014 at a special agro-ecological test site, which includes all the main micropositions of the moraine hill. At regular sampling points, the density and humidity of the soil under uneven grass stands were determined, and their porosity and aeration porosity were calculated. The results of the observations were processed by the method of three-factor analysis of variance. It is revealed that grass sowing is an effective method of regulating the water-air properties of the soils of the agrolandscape. About 43% of the spatial variability of indicators of water-physical properties of the soils of the moraine hill agroland are due to the characteristics of grass stands growing within it. As grass stands grow older, soil density increases as it reaches equilibrium values, their moisture increases as a result of a decrease in evaporative intensity, and the porosity and porosity of aeration decrease, but the effect of grasses on the physical properties of the soil increases. Young grass stands (1 and 2 years of life) determine one-third of the spatial variability of indicators of water-physical properties of landfill sites, and the older ones - half. The plant component of the agrolandscape has the maximum effect on spatial variability of density (62.3%) and porosity (51.5%) of soils. The spatial variability of other parameters of the soil water-air regime mainly depends on the peculiarities of the agrolandscape — vegetation determines 36% of the variability of soil moisture and 22% of the variability of aeration porosity. It is possible to form the following series in descending order of the influence of landscape factors on the spatial variability of the water-physical properties of soils under the grounds: individual properties of agromicrolandscapes within specific slopes, determining about 20% of the variability of their indicators; general features of moisture migration in the soil profile - about 18% of variability; the cumulative effect of the properties of all structural elements of the agrolandscape is about 10% of the variability; slope exposure — about 5%; soil specific features of different hydromorphism within specific AML — about 3%; soil hydromorphism — 0.4%.