Spatial heterogeneity of agrophysical properties of gray forest soils of the Northern Trans-Urals

The article presents the results of many years of research by the Department of Soil Science and Agrochemistry of the State Agrarian University of the Northern Trans-Urals. The purpose of the research is to study and evaluate the spatial heterogeneity of the agrophysical properties of virgin gray forest soils. A total of 111 full profile sections were made and described, and soil samples were taken for laboratory analysis. The results obtained were processed using the Descriptive Statistics tool in MS Excel. The tendency of natural compaction of the humus horizon (A1) was established: the density of soil structure averages 1.26 ± 0.10 g/cm3. In the Northern Trans-Urals, gray forest soils predominate with an above-average density in the upper part of the profile. The coefficient of variation is 8%, which corresponds to an insignificant degree of spatial heterogeneity. Down the profile, the density of soil structure increases to 1.39±0.07 g/cm3 in the humus-eluvial horizon (A1A2) and 1.52±0.09 g/cm3 in the illuvial horizon (B). The average values of the density of the solid phase along the profile vary in the range from 2.45 to 2.54 g/cm3, with a maximum manifestation in the A1A2 horizon. The variability is negligible. The porosity of the humus horizon (A1) of gray forest soils is 48% on average for the sample, which corresponds to an unsatisfactory state. Porosity decreases deep into the soil profile to 45% in the A1A2 horizon and 39% in the B horizon. When gray forest soils are involved in agricultural use, it is necessary to take into account the presence of an overcompacted layer in the illuvial horizon, which can impede the movement of water and lead to surface waterlogging.