Supplementary data: Integrated use of consortia-based microbial inoculants and nutrient complex stimulates the rhizosphere microbiome and soybean productivity

The data represent the impact of microbial consortia consisting of different combinations of Bradyrhizobium japonicum, Bacillus megaterium, Bacillus subtilis, and Azotobacter chroococcum with or without nutrient complex (S, Mg, Mn, Fe, Zn, Cu, B, and Mo) on the abundance and activity of microorganisms in the rhizosphere, soybean growth and development, as well as the quantity and quality of seed yield under field conditions.

A field experiment was performed to evaluate the responses of the rhizomicrobiome and soybean to seed treatments with multiple bacterial strains (Bradyrhizobium japonicum, Bacillus subtilis, Bacillus megaterium, and Azotobacter chroococcum), applied individually or in consortia, with and without nutrient complex (S, Mg, Mn, Fe, Zn, Cu, B, and Mo). Seed treatments with microbial consortia of Br. japonicum, B. subtilis/B. megaterium, A. chroococcum strains and nutrients had the highest effect on the abundance of total bacteria, azotobacters, nitrogen-fixing bacteria, actinomycetes, and activity of dehidrogenase in soybean rhizosphere. The highest effect on plant height, plant weight, pod number, pod weight, seed number, and seed weight was obtained from treatment with Br. japonicum strains with nutrients, followed by co-inoculation with B. megaterium and A. chroococcum. In comparison with the control and Bradyrhizobium single inoculation, a statistically significant increase in the seed yield was recorded in treatment with Br. japonicum, B. megaterium, A. chroococcum, and nutrients, reflecting the highest increase in protein and oil yield. The interactive effects of microbial consortia and nutrients could be used as promising seed technology for sustainable soybean cropping.