Soil sterilization leads to re-colonization of a healthier rhizosphere microbiome

Soil sterilization is often applied in cropping systems to remove soil-borne pathogens and nematodes. In an effort to better understand the role of sterilization on natural microbial communities and resultant plant growth, we examined the interaction between soil sterilization and the growth of three different crops (one native crop, peach; and two non-native crops, corn and tomato) in a soil known to have peach replant disease. Soil sterilization significantly increased plant growth in all crop species. The recovery of the microbial communities following sterilization was dependent upon the presence of a living plant and the final community structure differed between crop species. In all crops grown in the sterilized soil, there were common plant-beneficial microbial functions that were promoted after sterilization: N fixation, P solubilization, biological control, or root growth promotion. Despite the well documented effect of soil sterilization to remove pathogens, it is also a potential means to promote rapid changes in soil microbial communities and the apparent promotion of beneficial microbes as well as a healthier soil microbiome.