THE EFFECT OF PREPREVIOUS AND PRESUSPENDED INOCULATION OF SEEDS BY AZOTOBACTER VINELANDII 12M ON MAIZE PRODUCTIVITY AND ACTIVITY OF NITROGEN FIXATION PROCESS

Recent years in Ukraine are characterized by an increase in acreage under maize. The attention of agricultural producers is focused on the application of the latest technologies and intensification of production, which will allow not only to increase the yield, but also to improve the quality of grain. Traditional maize cultivation technology involves the introduction of high doses of mineral fertilizers and chemical plant protection products. However, breaches of technology, neglect of recommendations and insufficient scientific justification can cause dangerous environmental impacts for agroecosystems. Therefore, more and more often in modern technologies of cultivation of agricultural crops it is possible to find ecologically safe elements based on the use of biological preparations. The effect of different types of precursors and pre-sowing seed inoculation of Azotobacter vinelandii 12M strain on nitrogen fixation activity and maize productivity was determined in the interim field experiment. It was found that the conditions formed in the chernozem typical after growing legumes are favorable for the functioning of the native nitrogenfixing microbiota and the survival of the introduced strain Azotobacter vinelandii 12M. In the rhizosphere of maize plants the level of nitrogen fixation activity was higher by 3% in the variant where the clover was predecessor and by 17% where the peas were, compared with the same variants, but without inoculation. The complex of properties possessed by the strain Azotobacter vinelandii 12M, namely the ability to absorb inert molecular nitrogen, the production of phytohormones and the manifestation of antagonism against phytopathogens, made it possible to obtain maize grain yields of 6.79 and 6.88 t/ha, respectively. clover respectively. Protein content increased by 0.3–0.5%, fat (by 0.2%) and starch (by 2–3%). In the rhizosphere of maize plants grown after winter wheat, the activity of the nitrogen fixation process was half that of the leguminous precursors. The yield and quality of the obtained grain in the variants of constant cultivation of maize and cultivation after winter wheat were lower by 0.1–1% than after leguminous precursors.