Assessing how cover crops close the soil health gap in on-farm experiments

Assessing the success of cover crops (CCs) as a way to promote soil health at the farm scale remains a challenge. At four on-farm CC experiments in Nebraska, we quantified soil health relative to a reference soil. We examined physical, chemical, and biological properties in near-surface soil. Cover crops reduced the soil health gap between bare (no-CC) and reference soil in the short (3-yr) timescale, but the magnitude of responses depended on cropland management history and ecological dynamics of reference site plant communities. Increases in soil health relative to reference soils showed some relationship to increases in soybean [Glycine max (L.) Merr.] and corn (Zea mays L.) yields. Clear discrimination of reference from bare soils was most influenced by organic matter and infiltration measurements conducted under the highest sampling intensity. Framing soil metrics relative to reference soils and ensuring appropriate sampling intensity are important to quantify the effects of CC on farm landscapes.