Soybean Crop Response Treated With Different Multifunctional Inoculants Under Field Conditions

Soybean is the main crop in Brazilian agribusiness, but its production is limited by low soil phosphorus availability. An alternative to mitigate this constraint is the use of plant growth-promoting bacteria capable of solubilising phosphorus and producing phytohormones. This study aimed to evaluate soybean performance in response to different multifunctional inoculants under field conditions. Experiments were carried out in the 2021/22 and 2022/23 seasons in Santo Antônio de Goiás and in 2021/22 in Ceres, Brazil. The experimental design was a randomized block with 20 treatments and five replications. Treatments consisted of seed inoculation of DonMario 68i69 IPRO and NS 6906 IPRO cultivars with phosphate-solubilising bacteria (BRM 063573, BRM 67205, BRM 67207), auxin-producing bacteria (BRM 063574, BRM 36549, BRM 67206) and their pairwise combinations, plus five controls (Ab-V5, BiomaPhos, T0, T50, T100). Data were analysed using multivariate analysis in R and variance analysis (F test) at a 5% significance level, followed by Scott-Knott test. The combination BRM 67207 (Bacillus subtilis) + BRM 67206 (Bacillus pumilus) showed the best results across all experiments, enhancing pods per plant, grain yield, root biomass, total root length and root volume. This combination stands out as a promising bioinput for soybean production.