VEGETATION PERIOD OF SOY VARIETIES OF DIFFERENT MATURITY GROUPS DEPENDING ON INOCULATION AND EXTRA-ROOT NUTRIENTS UNDER CLIMATE CHANGE

Abstract

The article presents the results of studies of the influence of inoculation and foliar fertilization with multicomponent chelated microfertilizers on plant height, leaf surface area, and duration of interphase periods of mid-early and mid-ripe soybean varieties. We used biological preparations that do not harm the environment and meet all environmental standards. The medium-early variety of the Canadian selection Amadeus and the medium-ripening variety of the Ukrainian selection Samorodok were studied. It has been established that inoculation of seeds with bio-inoculants «Rizolain+Rhizosave», as well as foliar feeding with chelated microfertilizers in a complex with trace elements (bioactivator «Azotophyt-r» and growth stimulator «Organic-balance» in a complex with trace elements «HelpRost soybean» and «HelpRost boron» contributes to an increase in the leaf surface area by 3.2 thousand m2/ha in the Samorodok variety compared to the control. A slightly higher indicator was noted in the Amadeus variety, the leaf surface area in the same variants of the experiment increased by 3.4 thousand m2/ha compared to with control. In the soil and climatic conditions of 2022, a complex combination of pre-sowing seed treatment and foliar fertilization led to an increase in the height of plants of the investigated varieties by 10-23% compared to the control (from 1 cm in the phase of 2-3 true leaves to 14 cm in the phase of full maturity) . The increase in plant height of the investigated soybean varieties was associated with the extension of subsequent phenological phases of growth and development in connection with inoculation and foliar feeding. The use of high-quality inoculants with a high content of nitrogen-fixing bacteria for the treatment of leguminous seeds and biological preparations for feeding is now a necessity, as it allows to fully realize the genetic potential of modern varieties, and therefore to ensure the highest yields, which is especially important for organic cultivation. Obtaining a high-quality soybean crop with high profitability can be ensured due to the rational use of inoculants that have a positive effect on the accumulation of nitrogen in the soil. In this way, soybean plants are supplied with nitrogen and conditions are created for the accumulation of nitrogen for subsequent crops in the crop rotation.