Water-soluble components of soils on calcareous rocks in the Polar Urals

Abstract

A comparative analysis of the chemical composition and features of the water-soluble part of soils on calcareous rocks in the Northern part of the Bolshoi Paipudynskii Ridge (Polar Urals) was carried out. In the studied soils, significant differences in the content of water-soluble forms of organic carbon (5-80 g/kg), nitrogen (0.2-3.7 g/kg) and the amount of cations of readily soluble salts (1.5-32 g/kg) are largely determined by the phytocenotic factor (composition and structure of plant communities) and the influence of relief (steepness of slopes, nature of moistening). The surface horizons of soils that consist of the plants’ remains from the fall of previous years largely inherit the specific features of aboveground biomass. Moreover, they are characterized by minimal pHH2O values, accumulation of soluble organic forms C and N, and readily soluble salts. The concentration of cations in the composition of soluble compounds decreases significantly with depth. Regardless of the soil genesis, calcium cations (80-90%) and alkalinity-determining ions (80-97%) dominate in extracts from mineral horizons. Obtained data can be used to predict the behavior of elements in the soil and landscape, as well as for the balance calculation of carbon and nitrogen cycles.