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

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.