Granulometric composition of the finite moraine ridge soils of the Upper Volga postglacial region (East European plain, Tver region)

Abstract

At the experimental field of VNIIMZ (Tver region, village Emmauss) laid a series of 8 soil sections. The first three sections of the southern slope are confined to the transit-accumulative, transit and eluvial-transit microlandscape with a complex of gleevate and gleev soils, which changes to an eluvial-accumulative flat-topped section and similar microlandscapes of the northern slope with slightly bent and gleevate sod-podzolic light loamy soils. In samples taken every 10 cm, the particle size distribution of soils was determined by laser diffraction and sieve (>0.25 mm) methods. The differential distribution curves of soil particles are dominated by fractions of fine sand with a maximum content of diameters of 100–150 µm and silt (1–50 µm). Three granulometrically homogeneous layers are distinguished in the soil profile: the upper one with an arable horizon (0–40 cm), medium (up to 70–80 cm) and super-moraine (up to 120 cm). In the middle part of the soil profile of the northern slope, silty fractions prevail; and in the soils of the southern part of the landscape, a relatively high content of the sandy fraction is observed (the fraction of fine sand, 50–250 µm, dominates, and followed by the coarse silt fraction, 10–50 µm), which, apparently associated with the historical processes of profiles development on binary deposits, erosion, and, possibly, with modern agrotechnological processes.