Managing Global Resources for a Secure Future

The use of multi-species cover crop cocktails is being recommended by the Natural Resources Conservation Service (NRCS) to producers for the suite of potential benefits they provide agricultural systems. However, given the unpredictability in precipitation patterns, it is important to identify cover crop species that perform well under altered moisture conditions if producers are to adopt this practice. Identifying the most robust species may also maximize those intended benefits species are selected for. Currently, NRCS classifies cover crops under four primary functional groups: warm-season grasses, warm-season broadleaves, cool-season grass, and cool-season broadleaves. This study expanded those functional groups to six: warm-season grasses, warm-season non-leguminous broadleaves, warm-season leguminous broadleaves, cool-season grasses, cool-season non-leguminous broadleaves, and cool-season leguminous broadleaves. A two-phase study was conducted to help identify individual species and cover crop mixtures that exhibit resiliency under variable precipitation. The first phase consisted of a greenhouse screening of several cover crop species within each functional group. After selecting the best performing species, as measured by growth rates and total aboveground biomass production, cover crop monocultures were compared to mixtures varying in number of species and functional group types under a controlled environment. Findings from both phases will be presented.