FUNCTIONING OF SOYBEAN-RHIZOBIA SYMBIOSIS AFTER VARIOUS METHODS APPLYING TRACE ELEMENTS COMPLEX

Abstract

Objective. Investigate the effect of inoculation of soybean seeds with an active strain of nodule bacteria Bradyrhizobium japonicum T21-2 and treatment of seed or vegetative plants with a complex of trace elements Avatar-2 on the functioning of the symbiotic apparatus and grain productivity. Methods. Physiological, microbiological, gas chromatographic, vegetation experiment, statistical. Results. As a result of joint treatment of seeds with nodule bacteria and Avatar-2, inhibition of nodulation activity of nitrogen-fixing microorganisms in the stage of three true leaves was revealed in comparison with symbiotic systems formed as a result of standard inoculation of seed with rhizobia of Bradyrhizobium japonicum T21-2 strain. In the stage of budding / beginning of flowering and bean formation on the soybean roots of this variant, the number of nodules exceeded the corresponding figure in plants, bacterized without the use of trace elements by 16.6 % and 24.1 %, respectively. The combination of inoculation of seeds and feeding of plants during the vegetation with Avatar-2 did not have a significant effect on the activity of symbiotic systems in the stage of three true leaves and budding / beginning of flowering. However, in the stage of bean formation, a 38 % increase in nitrogen-fixing activity was detected compared to plants grown from seeds of rhizobia inoculated with Bradyrhizobium japonicum T21-2 strain (without the use of trace elements). Activation of soybean growth processes at all stages of plant development when exposed of seed bacterization and use of Avatar-2 by different methods was noted. Inoculation of seeds and using microfertilizers, both as separate elements of soybean cultivation technology and complex treatments in the conditions of vegetation experiment, resulted in a decrease in grain content of copper, zinc, iron and nickel. It was found that pre-sowing treatment of soybean seeds with a complex of chelated nutrients without bacterization caused an increase in grain weight per plant by 17.8 %, and when feeding non-inoculated growing plants with this fertilizer — by 27.5 % compared to the control. The combination of both factors — inoculation of seeds with a bacterial preparation and different using of trace element complex also had a positive effect on individual productivity of soybean plants, as evidenced by an increase of 14.4 % and 30.2 % compared to plants whose seeds were treated with rhizobia only. Conclusion. The combination of intensification factors in soybean cultivation technology through the use of different methods of complex microfertilizer and seed treatment with highly active strain of nodule bacteria has a significant impact on plant growth, content of individual trace elements in grain and creates a significant reserve of grain productivity of this crop.