Biological soil health indicators respond to tillage intensity: A US meta-analysis

•Tillage intensity can affect biological soil health indicators in many ways.•Reducing tillage intensity improves SOC, biological activity, and labile C and N fractions of SOM.•Reduced tillage effects are more expressive in the topsoil and when managed with complementary conservation practices.•Perennial systems are the best strategy for increasing biological soil health.•Biological indicators are sensitive to management practices, being useful for soil health assessment.