The effect of crop rotations and mineral fertilizers on the fertility of chestnut soil

Abstract

Relevance. The task of preserving and increasing soil fertility is urgent, since it is closely related to crop yields.Methods. The research was carried out in the arid zone of the Stavropol Territory at the Prikumskaya experimental breeding station in four 6-pole crop rotations from 1969 to 2022.The purpose of the research is to study the effect of saturation of grain crop rotations with pure steam on various nutrition backgrounds on the fertility of chestnut soil in the conditions of the Eastern Caucasus.Results. Over 53 years of research, the content and reserves of humus in the arable soil layer in grain-steam crop rotations decreased by 0.18–0.22% and 4.7–5.8 t/ha at the control, on a fertilized background — 0.04–0.08% and 1.0–2.0 t/ha, and in crop rotation without pure steam, on the contrary, increased, respectively, by 0.05% and 1.3 t/ha and 0.21% and 5.5 t/ha. On a natural background, the mineralization of organic matter took place much more intensively than on the variants with the introduction of fertilizers. Nitrate nitrogen reserves in crop rotations with 50.0% and 33.3% of pure steam decreased by 7.6 kg/ha and 1.3 kg/ha at the control, and on a fertilized background in crop rotation with 50.0% of pure steam — by 3.5 kg/ha. In other variants of the experiment, the amount of nitrogen increased. The maximum content of this element on all food backgrounds was noted in the crop rotation without pure steam. In all variants of the experiment, the content of mobile phosphorus and exchangeable potassium increased at the control by 0.7–2.5 and 31–62 mg/kg, and on a fertilized background by 7.2–20.0 and 12–38 mg/kg of soil. The application of mineral fertilizers contributed to an increase in phosphorus reserves by 13.6–44.6 kg/ha and a decrease in potassium by 20–63 kg/ha compared to the control.