SOIL MOISTURE RESERVES IN SOY-MAIZE CROP ROTATIONS IN THE CONDITIONS OF THE FOREST-STEPPE OF THE RIGHT-BANK

Abstract

To investigate the influence of the system of protection against harmful organisms on moisture and reserves of productive moisture in the soil in short-rotational crop rotations with different ratios of soybeans and corn in the conditions of the Right-Bank Forest-Steppe on gray forest soils. In the conditions of 2023–2024 years on gray forest soils in the phase of full germination of soybeans and corn, soil moisture in the arable layer (0–20 and 20–40 cm) was 18–20%, productive moisture reserves were 31–34 mm. During the growing season, both soil moisture and productive moisture reserves decreased due to the need of soybeans and corn for the formation of productivity. In the phase of the beginning of flowering of soybeans, soil moisture was 14–17%, in the phase of 12 leaves of corn – 13–17%, reserves of productive moisture, respectively, 18–25 and 18.5–28 mm. At the end of the growing season of soybeans and corn, these indicators were the lowest: in the phase of complete pouring of soybean seeds, they were: soil moisture 8–11%, reserves of productive moisture 5.8–11 mm; in the phase of milk-wax maturity of corn, respectively, 9–10% and 5.5–9 mm. A similar dependence on productive moisture reserves was noted in the 0–50 and 0–100 cm soil layers. The influence of the disease protection system on moisture and productive moisture reserves in the soil in soybean and corn crops was noted. The use of the disease protection system slightly reduced these indicators in the soil layer of 0–40 cm in soybean crops in the flowering phase by 0.2–1.0%, in the phase of full seed filling – by 0.2–0.6%. A similar dependence was noted regarding the impact of the disease protection system on soil moisture in corn crops. The influence of the ratio of soybeans and corn in short-rotation crop rotations on moisture and reserves of productive moisture in the soil was also noted. The highest soil moisture and reserves of productive moisture in the arable layer in the phase of the beginning of flowering of soybeans, respectively, 15.0–17.3% and 20.96–25.89 mm, were noted in unchanged sowing, in crop rotation with a ratio of crops, they were lower by 0.7–0.8% and 1.89–2.06 mm, in crop rotation with a ratio of 1:2 – by 0.8–1.4% and 2.07–3.29 mm, in crop rotation with a ratio of 1:3 – by 0.9–1.7% and 1.79–4.39 mm. The same trend was noted in corn crops.