Effectiveness of bioactive preparations as an element of ecologization of soybean cultivation

Topicality. In the world, the biologicalization of agriculture is determined not only by environmental and social, but also economic problems. Therefore, it is urgent to find and implement effective energy-saving and environmentally safe elements of crop cultivation technologies, in particular, the application of physiologically active preparations, such as plant growth stimulators and microelements. Issues. The effectiveness of stimulants, macro- and microelements depends on doses, forms, application terms and methods, environmental factors. Bioactive preparations require study, economic and ecological justification, adapt to the soil and climatic conditions of a specific ecological and geographical zone. Aim. To determine the optimal variants of mineral fertilizers application in combination with foliar dressing as well as treatment of seeds and plants of soybean varieties with bioactive preparations for 15–20 % productivity increase and biologicalization of crop cultivation. Methods. The field method was used to investigate the interaction of the studied factors on the plant growth and development and productivity of soybean; quantitative-weight method – to determine the yield structure; laboratory method – to determine the soil moisture content, mathematical and statistical method - to analyse and establish the reliability of the obtained results. Results. The research results showed that the indicators of productivity, energy assessment and moisture consumption for yield formation depend on influence of macro- and microfertilizers, treatment of soybean seeds and plants with Vympel stimulant and Oracle microfertilizer on different nutrition backgrounds. It was determined that the studied methods of seed treatment and foliar dressing ensured an increase in the soybean seed yield of Diadema Podillia variety by 0.09–0.67 t/ha, and of Samorodok variety by 0.12–0.65 t/ha depending on the level of mineral nutrition. At the same time, application of N10P26K26 resulted in an increase in soybean seed yield of Diadema Podillia variety compared to the control (without fertilizer) by 0.45–0.88 t/ha, the Samorodok variety – 0.36–0.46 t/ha; and when applying N20P52K52, the increase was 0.78–0.85 and 0.64–0.71 t/ha, respectively., 0.78–0.85 and 0.64–0.71 t/ha. Among all the studied variants, the highest seed yield of Diadema Podillya variety (2.93 t/ha) and Samorodok variety (2.80 t/ha) was obtained when pre-sowing seed treatment with Vympel-K, Oracul seeds, Oracul colofermin molybdenum was combined with treatment of plants in 2–3 true leaves stage with Vympel, and in the beginning of budding stage with Vympel, Oracul multicomplex, Oracul colofermin molybdenum, Oracul colofermin boron on the background of N20P52K52. The increase to absolute control (0.79 and 0.85 t/ha or 30.8 and 43.6 %, respectively) was obtained with the lowest moisture consumption for yield formation. In the same variant, but on the background of N10P26K26, the most energy efficiency ratio was 2.10 standard units (Samorodok variety) and up to 2.27 standard units (Diadema Podillia variety). The moisture consumption required to form 1 ton of soybean seeds was decreased for Samorodok variety by 27–36 %, and Diadema Podillya variety by 22–31 % compared to the control due to application of mineral fertilizers. The lowest moisture consumption was observed when the mineral fertilizers in the rate of N20P52K52, seed treatment and two foliar dressing was applied in the complex, and equalled 2452 m3 (Samorodok variety) and 2443 m3 (Diadema Podillia variety), which is less than control by 52 and 46 % respectively. Conclusions. The Vympel stimulators and Oracul microfertilizers increase the productivity of soybeans, reduce moisture consumption per unit of crop and increase the energy efficiency ratio. Key words: soybean, yield, bioactive preparations, mineral fertilizers, microelements, energy efficiency, water consumption.