AGRO-RECLAMATION TECHNIQUES AFFECTING SOIL WATER PERMEABILITY AND RICE PRODUCTIVITY UNDER SPRINKLING IN THE LOWER VOLGA REGION

Purpose: to substantiate scientifically the use of agricultural reclamation techniques in rice cultivation under sprinkling in combination with certain irrigation and plant nutrition regimes in light chestnut heavy loamy soils. Materials and methods. The studies were conducted on a site in Volgograd region from 2022 to 2024, with the tested variety Stalingrad 1. The studies were based on three factors: A (soil water regime) – two options were used; B (soil tillage) – three options were used; C (fertilizer rates) – two options were used. Standard research methods were used. Results. The highest water permeability was recorded during autumn plowing in combination with deep loosening carried out before rice sowing (В₃), amounting to 51.2 mm/h during the first hour of observations. The lowest absorption value was recorded with autumn plowing (В₁), where the rate was 32.8 mm/h. Under soil water regime А₁ together with В₁ and С₁, the minimum grain yield was obtained – 4.69 t/ha. In the moistening variant А₂, the highest yield was 6.95 t/ha with a combination of В₃ and С₂. The highest evapotranspiration was observed when cultivating soil В₁, varying from 6028 to 6402 cub. m/ha with an irrigation rate of 5100–5490 cub. m/ha. Conclusions. Cultivation of heavy loamy light chestnut soils, including autumn plowing to 0.25–0.27 m and before sowing aerobic rice to 0.40 m, compared to autumn plowing increases the soil water absorption rate by 18 mm/h after rice sowing. Maintaining an irrigation regime of 80 % HB at a depth of up to 0.4 m until the end of the tillering phase with a further increase to 0.6 m, with the addition of fertilizers at a dose of N₁₃₇P₇₄K₉₀ (7 t/ha) contributes to an yield increase to 6.95 t/ha and a decrease in irrigation rate by 600 cubic meters/ha.