Soil ecologists have debated the relative importance of dispersal limitation (“everything” is not “everywhere”) and ecological factors in determining the structure of soil microbial communities. The relative explanatory power of spatial and ecological factors, including plant species identity and even plant relatedness, for different fractions of the soil microbial community (i.e. bacterial and fungal communities) is poorly understood. In a new study published in AoB PLANTS, Burns et al. sampled field soils in a northern California field site to ask whether factors such as plant species, soil chemistry, spatial location, and plant relatedness influence rhizosphere community composition. They found that soil microbial community variation correlates most strongly with plant species identity, followed by soil chemistry, spatial location and plant genus.