The effectiveness of the use of trace elements in foliar feeding of soybeans in the conditions of the Western Forest Steppe

Abstract

Goal. To determine the effect of the use of micronutrients in the form of highly concentrated liquid fertilizers in foliar feeding on the dynamics of the formation of the leaf surface area, photosynthetic and symbiotic potential, indicators of individual productivity and yield of soybean seeds. Methods. Field, laboratory, quantitative, comparative calculation, mathematical and statistical. Results. Weather conditions during the years of research (2021–2022) were marked by significant deviations from the average long-term values according to the indicator “average daily air temperature” — in the direction of excess, according to the amount of precipitation — a deficit of precipitation was observed in some months, in some - their excessive amount, which had a significant impact on the growth and development of soybean plants, the formation of the seed yield of its researched varieties. The effect of microelements on the mentioned indicators varied significantly over the years of research. On average, over the years of research, 2-time treatment of crops in the phases of 4–5 trifoliate leaves and the beginning of flowering with trace elements ensured an increase in the leaf surface area of the Siverka variety by 3.9–21.7%, the Pallada variety — by 3.7–20.6%, photosynthetic potential — by 2.4–15.3 and 2.7–16.0%, respectively, total symbiotic potential — by 32.1–74.3% and 22.6–59.3% compared to the control. The number of beans per 1 plant of the Siverka variety increased compared to the control by 6.5–21.2%, the number of seeds from 1 plant — by 13.8–31.0%, the weight of seeds from 1 plant — by 11.1–27, 8%, the mass of 1000 seeds — by 1.8–6.3%. In the Pallada variety, the number of beans and seeds per 1 plant increased by 5.9–29.0 and 8.4–30.5%, the weight of seeds from 1 plant and 1000 seeds increased by 7.5–41.8 and 2.1 –9.0%, respectively. The seed yield increased in the Siverka variety from 2.73 t/ha in the control to 2.79–2.98 t/ha in the tested variants, in the Pallada variety — from 2.57 to 2.62–2.81 t/ha, or respectively by 2.2–9.2 and 1.9–9.3%. Conclusions. The use of trace elements in the form of highly concentrated liquid fertilizers for foliar feeding of soybeans in phases of 4–5 leaves and the beginning of flowering had a positive effect on the formation of the leaf surface area, indicators of photosynthetic and symbiotic potential, individual productivity and seed yield. Among the investigated options, the most effective for foliar fertilization was the use of highly concentrated liquid fertilizer Khimik Bor, the least effective was the use of Khimik Manganese or Khimik Copper.