EVALUATION OF BIOLOGICAL EFFICIENCY OF HUMIC GROWTH STIMULATOR IN SOYBEAN CULTIVATION

The research was conducted to determine the effectiveness of the use of a multifunctional humic growth stimulator potassium lignohumate brand "AM" with a high content of fulvic acids on soybean productivity in irrigated conditions. The work was carried out in 2021-2023 on a pilot irrigated area in the north of the Astrakhan region. The soil of the experimental area is light chestnut, brackish. The humus content in the arable layer was 0.9%, mobile phosphorus and potassium (according to Machigin) - 24.3 and 441.5 mg/kg of soil, respectively, the granulometric composition is medium loamy. The scheme of the field experiment included the following options: without treatment (control); potassium lignohumate of the AM variety in doses of 30, 50 and 70 g/ha. Over the years of research, the average daily air temperature ranged from +16.5 to +26.9 °C. July and August were quite hot, with maximum temperatures ranging from +34.1 to +38.7 °C. The relative humidity ranged from 41.6 to 47.7%. The average amount of precipitation during the growing season ranged from 12.0 to 22.7 mm. The soil temperature at a depth of 0.05 to 0.15 m ranged from 24.3 to 26.8 °C. The maximum number of grains per plant (138.3 pcs.), the mass of grains per plant (22.3 g) and the mass of 1000 seeds (212.3 g) were noted in the variant with a dose of 50 g/ha. Based on the results of a three-year study of productivity, variants with doses of 50 and 70 g/ha with a yield of 4.5 t/ha were identified.