Effects of coinoculation of Azospirillum brasilense and Bradyrhizobium spp. in soybean and inoculation of Azospirillum brasilense in corn

Soybean and corn are widely cultivated crops in Brazil and worldwide, and are raw materials for several industrial products. This work aimed to evaluate the co-inoculation of Azopirillum brasilense and Bradyrhizobium japonicum in soybean crops, as well as the inoculation of A. brasilense in corn in diferent locations of Goiás. Four field trials with soybean and four with corn were conducted in the 2023/24 summer harvest. All trials were installed in a completely randomized block design, with six treatments and four replicates. The treatments in the soybean trials were: control (without fertilizer and inoculation), non-inoculated control, standard inoculation (Rhizotrop 1), standard co-inoculation (Rhizotrop 1+Azotrop), co-inoculation Rhizotrop 1 + Nodofix AZP (formulation A) and co-inoculation Rhizotrop 1 + Nodofix AZP (formulation B). In the corn trials, the treatments were: control (without fertilizer and inoculation), 100% Urea, 75% Urea, 50% Urea and Azotrop TS standard, 75% Urea and Nodofix AZP TS (formulation A) and 75% Urea and Nodofix AZP TS (formulation B). In soybean, co-inoculation of B. japonicum and A. brasilense is more effective than inoculation with B. japonicum alone. Formulations A and B of soybean seed co-inoculation treatments similarly favor soybean nutrition, growth and yield. For corn, inoculation with A. brasilense is effective and reduces the demand for nitrogen fertilizer around 25%. Formulation A and B of the inoculation treatments of A. brasilense in corn seeds similarly favor the nutrition, growth and yield of this crop.