In a recent PEI study of cover crops for weed suppression, researchers compared 19 single species cover crops from four taxonomic groups (brassica, forb, grass, and legume) with 19 mixtures of varying species. They found that regardless of species diversity, the more biomass the cover crop produced, the less weed biomass was present. Highly productive species such as buckwheat and sorghum-sudangrass worked well alone and in mixtures underlining the importance of species selection in cover crop mixture design.
