Effect of 25 Years of No till Management on Soil Microbial Community Structure.

Archived soil samples from three Colorado dryland sites under wheat-corn-fallow rotations were analyzed by qPCR and pyrosequencing to analyze the effect of 25-years of no tillage management of soil microbial community structure and composition.   No tillage significantly increased bacteria abundance (16S rRNA copies / g soil) at all three sites with the largest gain (ca. 24-fold) at the driest site, which also saw the largest gains in soil organic carbon and water content.  Significant changes in bacteria community composition were also associated with site and no tillage management and the associated edaphic factors driving these factors will be presented.