Symbiotic effectiveness of Bradyrhizobium japonicum in acid soils can be predicted from their sensitivity to acid soil stress factors in acidic agar media

► Selected Bradyrhizobium japonicum strains tolerant of acid, Al, Mn stresses in agar. ► Symbiotic effectiveness on soybean in acid soils greater than acid-sensitive strain. ► Laboratory prescreening can select strains symbiotically competent in low pH soils.