Hritsyuk Y. Optimization of soybean yield formation processes in cultivation technology in the Right-Bank Forest-Steppe

The dissertation is devoted to the optimization of soybean cultivation technology of Muse variety in the Right-Bank Forest-Steppe of Ukraine by improving plant nutrition and activating growth and development processes by combining such technological methods as mineral fertilization and plant nutrition during critical periods of growth with pre-sowing seed treatment with mycorrhizal biological product and seed treatment agent, which is important in increasing plant resistance to environmental stress factors, maximizing the genetic potential and obtaining high yields. It has been determined that in the context of climate change, the optimal soybean cultivation technology is considered to be the one that involves the application of mineral fertilizers, sowing with seeds treated with a mycorrhizal biological product (Mycofriend) in combination with a disinfectant (Weibrans), as well as foliar feeding of plants with an organic-mineral microfertilizer (Helprost Soya) during critical periods of its growth and development, which stimulates plant growth, growth of aboveground mass and accumulation of dry mass by plants. The dependence of soybean seed yield on weather elements was established: July (r = -0.931) is closely correlated with the average monthly air temperature, and May (r = -0.875), June (r = 0.720) and August (r = -0.950) with the amount of precipitation per month. The largest joint effect of average daily air temperature and precipitation was found during the third decade of June (r = -0.938 and 0.996) and August (r = 0.976 and -0.999). Based on the established close correlations, curvilinear models of soybean seed yields relative to the parameters of agrometeorological conditions in the third decade of June and August were built, which allow for an accurate forecast of soybean yields in the Right-Bank Forest-Steppe of Ukraine. On average, in 2021-2023, the highest crude protein yields of 1.34 and 1.35 t/ha and crude protein accumulation rates in soybean seeds of 12.18 and 12.27 kg/ha per day were obtained for soybean cultivation with seed treatment with mycorrhizal agent and seed dressing and foliar feeding of plants with Helprost Soya fertilizer in the budding phase against the background of N15P45K60+N30 and N45P45K60 application. The highest rates of oil harvest of 0.81 and 0.82 t/ha and the intensity of oil accumulation in soybean seeds of 7.37 and 7.45 kg/ha per day on average over the years of research were obtained for soybean cultivation on the background of N15P45K60+N30 application with seed treatment with mycorrhizal agent and dressing and foliar feeding of plants with Helprost Soya fertilizer in the phase of branching and budding. In terms of the total intensity of protein and oil accumulation in seeds, the highest values were obtained for soybean cultivation on the background of N15P45K60+N30 application with seed treatment with mycorrhizal agent and seed dressing and foliar feeding of plants with Helprost Soybean fertilizer in the phase of branching and budding. Foliar feeding in the branching phase with the introduction of N15P45K60+N30 increases the intensity of the total accumulation of protein and oil in the seeds by 22.0%, in the budding phase - by 23.6%, which increases the indicator to 19.37 and 19.63 kg/ha per day, respectively, with its value in the absolute control of 15.88 kg/ha per day.The results of calculations of the economic and bioenergy efficiency of the studied agricultural measures showed that the cultivation of soybean variety Muse on the background of fertilizer N15P45K60+N30 with pre-sowing seed treatment with mycorrhizal preparation Mycofriend in combination with Weibrans disinfectant and foliar feeding with organic-mineral fertilizer Helprost Soya in the budding phase is an economically viable and energy-efficient agricultural measure, It ensures an increase in production profitability by 13.3%, profit by 19.4%, the cost of the grown crop by 15.4% and a decrease in the cost of 1 ton of seeds by 8.8%, an increase in energy accumulation in the crop by 13.4-15.4% and a KEE of 3.93.