Microorganism co-inoculation associated with potassium silicate doses on nutrition, production components, and yield of soybean

Soybean is a crop of significant economic importance, with its grains serving various purposes. In a scenario of increasing demand for food and environmental challenges, bioinputs emerge as effective alternatives to achieve sustainability. Thus, this study aimed to evaluate the co-inoculation of Bradyrhizobium japonicum and Bacillus aryabhattai, associated with potassium silicate doses in soybean cultivation. The experiment was conducted under field conditions using a randomized block design arranged in a 2 × 5 factorial scheme with four replications. The first factor consisted of microorganism inoculation (Bradyrhizobium japonicum and B. japonicum + Bacillus aryabhattai), and the second factor comprised foliar potassium silicate doses (0, 1.50, 2.50, 3.50, and 4.50 L ha⁻¹), applied in two growth stages (R2 and R3). A total of ten treatments were evaluated. The experimental plots consisted of eight rows, each five meters long, with a distance of 0.5 m between rows. The observational area of the plot comprised the four central rows, excluding one meter from the ends of the rows. Co-inoculation of B. japonicum and B. aryabhattai resulted in increased plant height but decreased the number of reproductive nodes compared to inoculation with B. japonicum alone. Inoculation with B. japonicum significantly increased the number of pods per plant and 100-grain weight. Co-inoculation with B. japonicum and B. aryabhattai and foliar application of potassium silicate doses did not influence K and Si contents in straw and grains and soybean grain yield.