Site: Kellogg Biological Station LTER

A KBS LTER graduate student collects soil cores in a prairie strip on the Main Cropping Systems Experiment.
Credit: Kurt Stepnitz

Twenty-plus years of nitrogen fertilization have caused rhizobia in soybeans to evolve toward reduced nitrogen fixation. These evolutionary changes have ecological consequences, as the evolution of reduced cooperation alters soil nitrogen availability. Directed changes to the microbial community, through plant-soil management or added bioinoculants, represents an important frontier for improving cropping system resilience.