The nature of alkalinity in virgin and agrogenic soils of solonetzic complexes in Volgograd oblast.

摘要

The nature of alkalinity in virgin and agrogenic soils of solonetzic complexes [central Solonetz, light-chestnut solonetzic, solonetzic agrozem, and carbonate-accumulative agrozem] was studied. It is shown that virgin soils are characterized by distinct differentiation of the profile with respect to the pH of pastes. In ameliorated soils, this differentiation is not well pronounced, because of a rise in pH of pastes in the surface calcareous horizon. It is found that the soils studied are characterized by a high percentage of organic alkalinity in the total alkalinity. High indices of saturation with respect to calcite in calcareous horizons of both virgin and ameliorated soils attest to the fact that some part of calcium from carbonates is easily released into the solution, so that Ca-saturated and supersaturated solutions are formed.