Urbanization causes rapid biodiversity loss. Reports also show impacts on bacterial microbiota in urban soil communities. However, it is unclear how urbanization affects the legume-rhizobia symbiosis. To investigate the effects of urbanization on this symbiosis, we developed a field study focusing on Trifolium ripens, collected 381 samples from rural and urban populations, and constructed linear mixed-effects models to determine which parameters explain above- and below-ground growth. The best-fit models, respectively, include the number of nodules and a coupled term including environment type as significant factors. Plant above-ground mass from urban environments was greater than that of rural plants given the same root mass, and urban plants had more nodules than rural plants given the same root mass. These findings suggest that urbanization impacts the legume-rhizobia symbiosis. We hypothesize that this is because differences in soil chemistry properties due to atmospheric deposition in urban areas or differences in soil rhizobia. We will characterize soil-inhabiting microbiota and evaluate abiotic factors that could explain differences in nodulation between urban and rural plants.