Cover crops alter soil physicochemical properties: A global meta-analysis

Cover crops are widely recognized for their potential to enhance soil health, but their effects on soil physicochemical properties under diverse conditions remain poorly understood. We conducted a global meta-analysis of 225 studies to quantify the impacts of cover crops on 15 key soil properties. Across all studies, cover crops significantly reduced soil bulk density by 3.2 % and penetration resistance by 11.8 %. They also increased water stable aggregates by 15.9 %, total porosity by 6.1 %, and water infiltration by 37.2 %. No significant changes were observed for soil air permeability, saturated hydraulic conductivity, soil pH, electrical conductivity, and cation exchange capacity. The effects of cover crops were influenced by climatic factors, management practices, and soil texture. Specifically, the mean annual temperature was positively correlated with reductions in bulk density and increases in soil water content, while mean annual precipitation correlated positively with changes in water infiltration and aggregate stability. Management practices, such as cover crop type, residue placement, and conservation tillage, further enhanced outcomes, with mixed and Poaceae cover crops showing the greatest improvements. Additionally, soil texture and initial soil pH influenced these effects, with fine- and medium-textured soils showing notable benefits. Relationships among soil parameters revealed synergistic improvements in porosity, infiltration, and aggregate stability, emphasizing the diverse benefits of cover crops to soil structure. These findings emphasize the significant potential of cover crops to enhance soil physical properties and water dynamics, establishing them as an essential component of sustainable agriculture in the context of climate change.