Evaluation of the effect of seed inoculation on soybean yields in Orel region

Soy is the main protein and oilseed crop of modern world agriculture. In the last decade, the area under this culture in the Orel region has increased dramatically - to 49.4 thousand hectares in 2016 and 68.7 thousand hectares in 2017. In 2001-2006, the total area occupied by this culture in the region did not exceed 0.7 thousand hectares. When legumes are introduced into new areas of cultivation, spontaneous population of rhizobia of the corresponding type is usually absent in soil. Therefore presowing inoculation of seeds with bacterial preparations based on highly active strains of rhizobia becomes an obligatory technique of cultivation. On the experimental base of the All-Union Research Institute of Leguminous and Cereal Crops (7 km from Orel) in 2011-2013 studies were carried out on the presowing treatment of soybean seeds with Lancetne and Noktin and Optimize preparations. These preparations contain living microorganisms Bradyrhizobium japonicum, which are symbiotic nitrogen fixers. A sharp activation of nitrogenase activity was established due to their application. The activity of nitrogenase in the variant with presowing inoculation of soybean seeds with the preparation Noktin increased to 36.7 μg N/plant/hour, which is 29.9 μg N/plant/hour more than in the control variant (in the control variant, nodulation occurred in account for the small populations of nodule bacteria in the soil, which is associated with low nitrogenase activity). All variants with the inoculation of soybean seeds with preparations of Noktin and Optimisms provided an excess of 11.9-13.5% over the control over the control (on average for 3 years) and a content of crude protein in seeds up to 1.8%.