Effect of Mobile Potassium Content in Soils on Grain Crop Yields and Potash Fertilizer Costs on Its Formation

The influence of the content of mobile potassium in various soils on the yield of grain crops and the effectiveness of the use of potash fertilizers for them is shown. The results of the study showed that an increase in the content of mobile potassium in the studied soils contributes to an increase in the yield of grain crops and at the same time reduces the effect of potash fertilizers. Despite this, the total yield obtained due to an increase in the potash level of soils and an increase in yield from the application of potash fertilizers far exceeded all variants of potassium doses on soils with low K₂O. The increase in yield from the application of potash fertilizers was 29–46%, depending on the crop, while the total yield increased by more than 2 times. At the same time, the costs of potash fertilizers for the formation of grain yields decreased. The consumption of potassium fertilizers for obtaining 1 ton of winter wheat grain on sod-podzolic soils when applying K30–60 decreased from 19–36 to 10–19 kg/t, on gray forest soils – from 12–23 to 10–20 kg/t, spring wheat – from 25‒47 to 15–31 kg/t on gray forest soils and from 23–43 to 15–30 kg/t – on leached chernozems.