Agrogenic transformation of the main properties of the clear-gray forest surface clay soil of the Western Forest-Steppe

Goal. In the conditions of the classical stationary experiment, to study the influence of long-term (55 years) use of various fertilizer systems and periodic liming on the dynamics of physico-chemical and agrochemical properties of clear-gray forest surface clay soil. Methods. Field (long-term stationary experiment), laboratory-analytical (determination of physicochemical and agrochemical parameters of the soil), calculation-comparative (identification of similarities and differences between the obtained values), mathematical-statistical (justification of the reliability of the obtained data). Results. The study was carried out in a long stationary experiment, laid down in 1965 at the Institute of Agriculture of the Carpathian Region of NAAS. With an intensive mineral fertilizer system during five 7-field rotations, along with the accumulation of nutrients, pHKCl decreased by 3.8 units, Ng rose to 6.43 mg × eq./100 g of soil, the content of mobile aluminum compounds increased to 132.0 mg/kg of soil. With the replacement of the 7-field rotation with a 4-field rotation, the hydrolytic acidity for four rotations decreased to 4.49 mg × eq./100 g of soil, the content of mobile aluminum compounds was 59.9 mg/kg in the control without fertilizers. Conclusions. Based on the obtained results, it was found that the replacement of a 7-field crop rotation with a 4-field crop rotation, avoiding intensive crops (potatoes and sugar beets), contributed to a decrease in excessive mineralization associated with the intensity of crops and the cultivation factor. Suspension of application of high doses of mineral fertilizers against the background of a significant amount of residual phosphates and potassium, together with the plowing of the 2nd hay crop of the meadow clover, played an important role in the cultivation of soils: the acidity of the soil solution and the content of mobile aluminum compounds were reduced, the processes of humus formation were intensified, the nutrition mode was improved and favorable conditions for the functioning of soil ecosystems were created.