Site-specific distribution and competitive ability of indigenous bean-nodulating rhizobia isolated from organic fields in Minnesota

•First report on the diversity of indigenous dry bean-nodulating rhizobia obtained from organic farms.•Most sampling sites in the southern part of Minnesota lacked large numbers of indigenous dry bean-rhizobia.•Organic fields in Minnesota harbor highly diverse and site-specific strains of indigenous dry bean-rhizobia.•One of the indigenous dry bean Rhizobium strains, orgK9, has potential for use as a novel organic inoculant due to its efficient N2-fixation potential and competitive ability.