Dynamics of soil fertility in agricultural lands of the forest-steppe of the south of Western Siberia

The paper presents the results of research on the dynamics of soil fertility indicators in the forest-steppe in the Lyubinsky district of the Omsk region. Soil surveys were carried out in 1987-2022 by FSBI Agrochemical Service Center “Omskijˮ. Meadow-chernozem soils are located on a slightly undulating plain, which occupy 11 044 hectares, which is 50.4% of the land area of the rural settlement of 21925 hectares (soil map of 1988), of which 8884 hectares are arable. On the low plain, meadow soils account for 920 hectares or 4.18% of the area, of which 230 hectares are arable. In the upland depressions, solonetzes are 3415 hectares or 15.54% of the area, of which 551 hectares are arable. In swamp depressions, meadow-marsh soils - 83 hectares or 0.38% of the area. Swamp soils - 190 hectares or 0.87% of the area. Salt marshes - 10 hectares or 0.04%. In the hollows of malt there are 5886 hectares or 26.87% of the area, of which 38 hectares are arable. Other soils - 377 ha or 1.72%. A decrease in the amount of mineral and organic fertilizers applied annually has affected the change in the agrochemical properties of the soil. The decrease in the amount of mineral and organic fertilizers applied annually affected the change in the agrochemical properties of the soil of the forest-steppe zone of Western Siberia. The survey of the studied territory showed that the weighted average humus content in arable soils decreased from 5.9% in 1987 to 5.57% in 2022. The weighted average content of mobile phosphorus also decreased from 95 to 69 mg/kg of soil. The area with an increased and high content of it decreases and increases with a low one. The content of mobile potassium is consistently high. The acidity of the soils has not changed. According to the results of the survey, there is a decrease in some indicators of soil fertility. Due to the negative changes in a number of indicators of soil fertility in part of the land-use area, measures are needed to stabilize them.