Fig 1.

Principal-components analysis of microbial communities from six field sites with no-till and plowed soil treatments at sampling depths of 0 to 5 and 10 to 20 cm. Confidence ellipses (95% confidence) are drawn around the barycenters of treatments, including till treatment (broken line) and no-till treatment (black line). (A) General 16S rRNA bacterial communities. The two dimensions explain 33.5% of the variance. (B) Actinobacterial communities. The dimensions explain 37.6% of the variance. The numbers 1 to 6 represent the experimental fields described in Table 1.