Purpose. To determine and scientifically substantiate the optimal combinations of regimes for regulating soil moisture by irrigation and the use of biological plant-protecting agents at various stages of their growth and development, ensuring the minimization of anthropogenic impact on the environment. Materials and methods. The studies were conducted in 2021–2022 on the experimental site of the All-Russia Research Institute of Irrigated Agriculture near the village Vodny, Sovetsky raion, Volgograd oblast, in plantings of the Gulliver potato variety in a two-factor field experiment. Factor A: A1 was the moisture content of the soil layer 0.4 m deep throughout the entire potato-growing season was maintained at a level not lower than 70% of the minimum moisture capacity; A2 was the same, only at 80% of the minimum moisture capacity. Factor B: B1 was biological system of potato plant protection; B2 was integrated protection system; B3 was chemical protection system (control). The experiment was carried out on light chestnut, heavy loamy, low-humic, nonsaline soils. In terms of precipitation, the years of research are characterized as: average wet in 2021 and average in 2022. Results. In the first option of the irrigation regime, the irrigation rate of 2720 and 3060 cubic m/ha was provided with eight and nine irrigations. The second irrigation regime was maintained with almost twice as many irrigations, up to 15–17, but the watering rate decreased to 230 cubic m/ha and the irrigation rate increased to 3450–3910 cubic m/ha at the same time. In the option of the moisture regime of 80% of the minimum moisture capacity in a horizon of 0.4 m, in conjunction with a plant-protection system based on the use of biological preparations, the largest green matter of 385 g/plant, which is 98 g/plant more than control, was obtained. The maximum mass of tubers in the nest was also obtained in this combinable option; it was 660 g/plant, which is 30% higher than the option with chemical protection. Conclusions. On low-fertility light chestnut soils of the Lower Volga region, potatoes are best cultivated at a moisture regime in which humidity does not fall below 80% of the minimum moisture capacity in a soil horizon of 0.4 m, in conjunction with a plant-protection system based on the use of biological preparations, which provides favorable conditions for obtaining a tuber yield of 32.4 t/ha.
Rodin et al. (Mon,) studied this question.