Changes in Agrochemical Parameters of Typical Chernozem Soils Caused by Various Cultivation Techniques, Chemization, and Biologization

This paper examines effects caused by basic soil cultivation techniques combined with the integrated application of mineral fertilizers and biopreparations amid the manure and green manure aftereffects on the agrochemical parameters in the arable (0–25 cm) and subsurface (25–50 cm) layers of typical chernozem soils. It is established that disk plowing significantly (by 2–4 times) improves all agrochemical parameters in both layers in comparison with the control soil. The aftereffect of manure increases the efficiency of disk plowing. The highest humus content (5.4% in the arable layer and 5.1% in the subsurface layer) was registered at the end of the growing season of 2020 after the application of biopreparation V417. At the beginning of the growing season of 2019, the integrated application of mineral fertilizers and the biopreparation ensured the highest content of mobile phosphorus and potassium in both layers: 36 and 290 mg/kg in the arable layer and 32 and 220 mg/kg in the subsoil layer, respectively. The highest nitrate nitrogen content was reached at the end of the growing season of 2020 as a result of the biopreparation application amid the aftereffect of spring rape green manure: 28 mg/kg in the arable layer and 21 mg/kg in the subsoil layer. In the course of the experiment, the content of humus and mobile potassium increased from the low to the medium level, while the content of nitrate nitrogen and mobile phosphorus increased to the elevated level. By its aftereffect, spring rape is a more efficient green manure culture in comparison with the mix of spring oats and forage sorghum. In 2020, the efficiency of the spring rape aftereffect was only 10% lower in comparison with manure; therefore, taking the low availability of manure, green manure can be considered a worthy alternative to it. Combined with the application of mineral fertilizers and biopreparation V417, disk plowing performed amid the green manure (spring rape) aftereffect makes it possible to preserve and restore the fertility of chernozem soils in the Chechen Republic and reduces mechanical impacts on them. Surface tillage with disk harrows combined with the use of green manure is a preferable cultivation method for arid regions featuring dry growing seasons.