Beyond species richness: disentangling contributions of cover crop traits to weed suppression in mixtures

Ecological theory suggests that diverse plant communities should be more resistant to plant invasion; however, empirical studies with cover crops often fail to show greater weed suppression in species-rich mixtures compared to that observed in the most weed-suppressive cover crop grown in monoculture. Our objective was to examine how the traits of cover crop species grown in mixtures influence weed suppression and to develop new metrics for assessing the relative performance of mixtures with regard to weed suppression and effects on subsequent cash crops. We conducted a two-year field experiment in southeast New Hampshire, USA. Treatments were mixtures and monocultures of annual broadleaf, …