EFFICIENCY OF APPLICATION OF COMPLEX MICROFERTILISER ORACLE MULTICOMPLEX IN SOYBEAN CULTIVATION IN CONDITIONS OF THE CENTRAL BLACK EARTH REGION OF THE RUSSIAN FEDERATION

In the context of a significant reduction in the use of mineral fertilizers during the transition to ecological land use, domestic agriculture is interested in using alternative agricultural technologies aimed at providing plants with additional sources of mineral nutrition. The importance of microbiological preparations and microfertilizers that can increase soybean resistance to diseases and stress, compensate for the lack of nutrients in critical phases of growth and development, and increase its productivity is noted. The aim of the study was to study the effect of Rizotorfin and complex organomineral microfertilizer Oracle multicomplex on the yield and grain quality of new promising soybean varieties. In 2022-2024, the studies were carried out on the variety with a determinate type of stem growth Orleya bred by the Federal Scientific Center of Plant Breeding and the indeterminate variety Leader 10 bred by AST LLC. The positive influence of technological methods on the growth and development of new soybean varieties was noted: plant height increased by 4.15-11.41% on average for 3 years in the variety Orleya and 5.98-13.90% in the variety Leader 10. Moreover, the highest effect of 11.00 % and 14.00 % in both varieties was observed in the combined application of inoculation and Oracle multicomplex. Depending on the treatment, root length increased compared to the control in the variety Orlea by 5.74-9.72% and in the variety Leader 10 by 6.90-15.34%. The formation of plant dry mass was most effectively influenced by the application of Oracle multicomplex: the highest aboveground dry mass was 2.13 g/plant in Orlea and 2.6 g/plant in Leader 10, root dry mass was 0.42 g/plant (Orlea) and 0.52 g/plant (Leader 10). The maximum number of nodules 18.90 pcs/plant and the highest dry mass of nodules 37.00 mg/plant were formed in Orlea in the variant Rhizotorfin+Oracle multicomplex; in Leader 10 in the variant with inoculation - 18.97 pcs/plant and with foliar feeding - 48.64 mg/plant, respectively. On average for 3 years in the studied varieties the number of productive beans increased by 24.52-65.88%, the number of seeds - from 28.82% to 67.28% depending on the variant. Leader 10 in the variant Rhizotorfin+Oracle multicomplex was distinguished by the maximum number of productive beans (52.40 pieces) and seeds (112.68 pieces). The maximum yield was observed in the variety Orlea when using Rizotorfin 2.74 tonnes/ha. The variety Leader 10 had maximum crude protein content in grain 45.83-46.33% on average for 3 years A high to medium level correlation was found between nodule number and yield in 2022 r=0.85 and 2023 r=0.52, between nodule dry weight and crude protein content of soybean seeds in 2022 r=0.79, in 2023 r=0.52. In 2024, a medium level correlation was observed between nodule number and crude protein content r=0.34.