Under Cover: Secrets to Using Companion Crops in Establishment of M. x Giganteus.

Miscanthus x giganteus is of interest for bioenergy because of its high biomass yields and low input requirements. The deep-rooted perennial grass has garnered attention for potential to build soil organic matter and sequester atmospheric carbon, particularly on marginal lands. There is a risk however, that M. x giganteus establishment can degrade sensitive or highly erodible land because current planting practice leaves much of the soil surface exposed for 1-2 years. One way to mitigate this risk might be to plant M. x giganteus with a companion crop that can provide soil cover and reduce erosion during the establishment period. We are evaluating the potential of nine companion crops to 1) facilitate growth and overwinter survival of M. x giganteus and 2) compete for water and light resources. Early results suggest that companion crops can reduce M. x giganteus  biomass yield by 80%% in the first year, but do not negatively impact crop survival during the critical first winter. Growth in the second year indicates good opportunity to select companion crops for M. x giganteus that improve ecosystem service with minimal impact on biomass yield.