Cover crop mixtures enhance multiple ecosystem functions: A global meta-analysis

Cover crop mixtures have been increasingly adopted across agroecosystems worldwide due to their potential to improve soil health and ecosystem functioning. However, it is not clear whether and how cover crop mixtures vs. single cover crops might influence different ecosystem functions. Here, we selected 1895 paired data from 61 studies worldwide to evaluate the role of cover crop mixtures in affecting biomass production, soil properties and subsequent main crop yields in comparison with single cover crops. We also assessed whether the number of plant species in cover crop mixtures, crop field types and cover crop combinations could affect ecosystem functioning. Multi-species mixtures increased cover crop above-ground biomass by 21.7%, carbon and nutrient accumulation (C: +27.7%, N: +27.7%, P: +22.8%, K: +24.1%), and subsequent crop yields by 4.9% compared to single cover crops. These benefits were most pronounced in paddy fields (e.g. a 35.3% increase in biomass), as well as in specific species combinations such as milk vetch-rapeseed (32.8%) and milk vetch-ryegrass (36.0%). Also, multi-species cover crop mixtures increased subsequent soil moisture content (+1.5%), soil total nitrogen (+5.8%), soil microbial carbon (+37.8%), soil microbial nitrogen (+37.6%), Chao1 index of fungi (+12.6%), decreased soil bulk density (-7.0%), soil electrical conductivity (-9.5%) and polyphenol oxidase activity (-7.0%). However, effects on soil pH, organic matter, and most nutrients were neutral unless specific combinations. Synthesis and applications. Multi-species cover crop mixtures significantly enhance agroecosystem productivity and soil health, particularly in paddy systems and when combining functionally complementary species (e.g. legumes with Cruciferae, legumes with Gramineae). Farmers and policymakers should prioritize tailored mixtures over monocultures to optimize biomass production, nutrient cycling and yield resilience. For maximum impact, mixtures should align with local conditions-such as using milk vetch-rapeseed or milk vetch-ryegrass in humid regions-to advance sustainable agriculture and climate adaptation goals globally.