SOIL MANAGEMENT IN AGROECOSYSTEMS - IMPACT ON THE СATION-ANION COMPOSITION IN THE AERATION ZONE OF SOILS

The research aimed to analyze the cation-anion composition of the soil solution in dark-grey podzolized soil under the influence of long-term anthropogenic factors. Over the extended application of both mineral and organic fertilizers, changes in the cation-anion composition of the soil were observed, depending on the dosage of mineral fertilizers and their distribution within the soil profile. When the amount of mineral fertilizers was increased from 265 kg NPK per hectare to 397 kg per hectare, a noticeable decrease in soil solution pH was observed, with pH levels dropping to 6.1 and 6.0, as compared to the control variant without any fertilizer application, which exhibited a pH of 6.3. The application of mineral fertilizers and manure additionally enriched the soil with ions of organic and inorganic acids, what became the reason for the redistribution between mobile and immobile forms of calcium and magnesium in the direction of increase of their mobility beyond the soil profile. The greatest accumulation of sulphate was observed at a depth of 160–280 cm due to the migration of their water-soluble forms. The main quantity of chlorine was moved and accumulated in the soil layer of 120–280 cm, and the increase of mineral fertilizers increased the content of chlorine in the aeration zone.