ECOLOGICAL SIGNIFICANCE OF LIMING FOR PRESERVING GRAY FOREST SOIL FERTILITY WITH MINERAL FERTILIZER APPLICATION

摘要

It is shown that with the systematic use of mineral fertilizers and liming on gray forest soil, the acidity indices, calcium content, mobility and fractional composition of mineral phosphates and mobile forms of heavy metals as well as the yield of crops in rotation change substantially. Gray forest soils in the Orel Oblast occupy 46.3% of all farmlands and 52.7% of plowlands, of which 43% belong to strongly and moderately acid, more than 80% needs liming. The unfavorable physicochemical properties of these soils for growth of crop plants are due to depletion of the plow layer in bases under conditions of periodic flushing regimes and negative calcium balance due to a decrease in the volume of liming [1, 2]. According to the data of studies [3], theuptake of radionuclides and heavy metals into plants is determined by the regime of formation of the reaction of the medium, by ecological functions of the transformation of calcium and magnesium salts. Under conditions of the Orel Oblast, cultivation of early varieties of sunflower and corn makes it possible to obtain high (2.0-2.5 tons/ha) yields of oil seeds and 6-8 tons/ha of corn grain. However, there is no information about the effect of liming on the physiological characteristics of these crops.