Optimizing the conditions for the formation of soybean productivity under different cultivations in agrocenosis

Goal. To study the influence of different systems of main tillage and background nutrition on the growth, development, and formation of productivity of soybeans on podzolized chornozem in the Central Forest-Steppe zone. Methods. Field (to determine the interaction of the object of research with biotic and abiotic factors), measuring and weighing (to determine biometric indicators of plant growth and development, as well as the level of yield, and to establish the parameters of the crop structure), mathematical and statistical (to process experimental data). Results. Optimum technological methods of soil cultivation were determined, which ensured favorable agrophysical conditions of podzolized chornozem (2021–2023) and the greatest increases in grain productivity of soybeans of the Muza variety. The most favorable conditions for soil compaction in a layer of 0–30 cm were created during traditional plowing with density indicators within the optimal values of 1.05–1.16 g/cm3 with total porosity of 53.18–61.20% and porosity of aeration of 28.32– 48.41%. Traditional plowing and surface tillage on average provided the highest yield indicators — 2.23–3.12 and 2.2–3.10 t/ha and a significant increase in additional yield — 0.48–0.89 t/ha, or 21,5–39.9% and 0.50–0.90 t/ha, or 22.7–40.9% in versions with and without fertilizers. Application of fertilizers in a dose of N45P45K45 in a complex with 2-time foliar top dressing with an organo-mineral fertilizer based on potassium humate with a balanced content of macro- and microelements was effective, contributed to optimizing the nutrition of soybean plants and provided the highest increase according to the experiment — 0.72–0.90 t/ha (29.9–40.9%). Conclusions. The results of 3-year studies indicated the same effectiveness of traditional plowing (by 20–22 cm) and surface long-term cultivation (by 8 cm) against the background of the optimal dose of fertilizers (N45P45K45) in combination with foliar top dressing with potassium humate in the stages of organogenesis of VVSN 11–13 and VVSN 61–62. These options ensured the formation of the largest number of beans on 1 plant — 47.8 and 47.6 pcs.; seeds — 110.4 and 110.9 pcs.; seed mass — 22.0 and 22.2 g; 1000 seed weight — 199.3 and 198.4 g, and the maximum level of soybean yield — 3.12 and 3.10 t/ha with a significantly higher increase in additional yield depending on the nutritional background — 0.89 and 0.90 t/ha, or 39.9 and 40.9%.