Anisotropy of the properties of some anthropogenically transformed soils of podzolic type

Abstract

It is shown that the horizons and profiles of anthropogenically transformed soils of podzolic type—light typical agrozems, typical texture-differentiated soils developed from glaciolacustrine loamy sands and clays and from noncalcareous mantle loams, agrosoddy deeply podzolic soils developed from noncalcareous mantle loams, and agrosoddy shallow-podzolic soils developed from noncalcareous mantle loams and from calcareous loams underlain by ancient glaciolacustrine loams and clays—are characterized by some anisotropy of most of their properties. The highest anisotropy is typical of the field water content, bulk density, and total porosity. The coefficients of anisotropy (gradients) calculated for the separate horizons as the ratios between the values of the properties measured in the horizontal and vertical directions (k = Phoriz/Pvertic) of these properties are much higher than those of other soil properties. The coefficient of anisotropy of the soil profile (K) is suggested as the coefficient of correlation between the values of a given property determined in the horizontal and vertical soil sections. For the considered properties, K varies from 0.4 to 0.6. For other soils properties, such as the solid phase density, the electrical resistance determined in a laboratory and in the field, and the organic carbon content, the coefficients of anisotropy are close to 1.0. The clay content has an intermediate anisotropy. The values of anisotropy and its direction (gradient) should be taken into account upon the assessment of the soil physical properties and the processes controlling them; this is particularly important in the study of soil transformation. The revealed regularities of the soil anisotropy make it possible to suggest a new interpretation of the data on the distribution of water and energy in soil profiles.