Cover crops should be polycultures (online)

First-of-kind study suggests cover crop mixtures increase agroecosystem services

  

Planting a multi-species mixture of cover crops — rather than a monoculture — between cash crops, provides increased agroecosystem services according to US researchers. That was the conclusion drawn from a two-year study of 18 cover-crop treatments, ranging in diversity from one to eight plant species. Cover crops were grown preceding a corn crop, with species including oats, canola, sunn hemp, soybean, barley, perennial ryegrass, forage radish, cereal rye, millet, sudangrass, red clover and hairy vetch. Five benefits of cover crops were measured, including weed suppression and nitrogen retention, cover-crop above ground biomass, inorganic nitrogen supply during the subsequent cash-crop season and subsequent corn yield. The research is published in the September 2016 issue of the Journal of Applied Ecology.