Inoculation with Bradyrhizobium sp. and Azospirillum brasilense Associated with Application of Cobalt and Molybdenum on Nutrition and Soybean Yield

Abstract

Considering the main current limitations and potential of biological fixation of N 2 (BNF) in soybean crop and benefits attributed to various crops by inoculation with Azospirillum brasilense (diazotrophic bacteria with free life), with emphasis on larger development of the root system and consequently greater absorption of water and nutrients, we can infer that co-inoculation with both microorganisms of Bradyrhizobium sp. and A. brasilense can improve the crop performance in an approach that meets the current demands of agricultural, economic, and environmental sustainability. Thus, important researches are needed to evaluate the nutritional status, production components, and the soybean yield affected by cobalt and molybdenum application mode and co-inoculating seeds with bradyrhizobia and A. brasilense. We found that seed inoculated with A. brasilense and application of cobalt and molybdenum provided higher N concentration in leaf and mass of 100 grains, with a positive impact on the grain yield of soybean, with an increase of 1007 kg ha -1 of grain, equivalent to 18.4% more than the control (only inoculated with rhizobia). This research demonstrated that co-inoculation with Bradyrhizobium sp. and A. brasilense associated with the application of cobalt and molybdenum is beneficial for nutrition and soybean yields.