•The survival model of generic E. coliin soil exhibited biphasic properties.•Soils containing buckwheat suppressed E. coligrowth by more than 1-log CFU/g.•E. coliwas not detectable after 30 days for soils with buckwheat/mustard greens.•The E. colipopulation of control soils was greater than 2-log CFU/g after 40 days.•Cover crops may improve on-farm agricultural soil management practices.