Soybean inoculation techniques for the region of Tangará da Serra - MT, Brazil

The use of inoculated microorganisms on seeds has increased in Brazil, as they help on the fixation and use of nutrients by plants, promoting increasing yields, mainly due to the reduction in the application of nitrogen fertilizers. The aim of this study was to evaluate the influence of single inoculation and co-inoculation of Azospirillum brasilense and Bradyrhizobium japonicum bacteria on seeds and foliar inoculation on soybean, in the region of Tangara da Serra – MT, Brazil. The experimental design used was a randomized block with 9 treatments and 4 replicates. The treatments were composed by using B. japonicum and A. brasilense bacteria in different combinations and times of application on seeds and sprayed on the leaves. The use of A. brasilense together with B. japonicum significantly improved the agronomic characteristics of the evaluated soybean cultivar. There was an increase in yield with the use of A. brasilense through the co-inoculation technique when compared to the single use of Bradyrhizobium. The use of co-inoculation at V3 soybean stage promoted higher nodulation and yield than the standard inoculation performed in the seeds, ensuring better results of nodulation and yield besides increasing the size of the soybean root system, when there and co-inoculation techniques were implemented.