Efficiency of using new Rhizobium strains on legume crops

During significant time, the use of bean-rhizobial systems and development of effective, competitive microbial preparations have been an integral part of organic farming. Also, in intensive technologies, only due to such ones, it is possible without reducing the achieved level of agricultural production to reduce its cost, harmful effects on the environment and at the same time to achieve ecological purity of products selection of highly effective strains that have adapted to local soil and climatic conditions and acquired resistance to nutrients and plant protection is the most promising strategy to increase the effectiveness of microbial inoculants. The aim of this work was to select highly effective strains that have adapted to local soil and climatic conditions and have become resistant to nutrients and plant protection and are the most promising for improving the effectiveness of microbial inoculants. Field researches were conducted in the research fields of the Skvyra Research Station of Organic Production of the Institute of Agroecology and Environmental Management of NAAS (Ukraine, Kyiv region, Skvyra) during 2020–2021. Nitrogen-fixing activity of root nodules was determined by acetylene method. The gas mixture was analyzed on an «Agilent 6850 chromatograph». The paper presents the results of research to establish the effectiveness of new strains of inoculants on crops of legumes: soybean of Moravia variety and peas of Starter variety in the Kyiv region, Skvyra Research Station of Organic Production of the Institute of Agroecology and Environmental Management of NAAS. The significant effect of new rhizobia strains for inoculation of legumes on phenological indicators and yield of these crops in the conditions of intensive technologies was shown. The competitiveness of strains is controlled by both internal determinants — genotype of the microorganism, and external factors such as symbiont plant physiology, exposure to abiotic factors, tolerance to pesticides and agrochemicals used in crop production technologies. It has been shown that the use for inoculation of soybean strain B. japonicum EL 35 and for inoculation of peas strain R. leguminosarum bv. viciae PS 12 stimulate the development of plants during their growing season and allow to obtain symbiotic systems with a high level of nitrogen fixation, as a result of which we can increase the yield of legumes from 16 to 20%.