When we hear talk about cover crops, most of us think of row crop agriculture. But annual cover crop species can be used for more than cover in rotations with agricultural crops. A U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) Plant Materials Center in Missouri recently completed an evaluation of annual covers to suppress weeds during the establishment of woody seedlings in comparison to traditional weed suppression practices.
Three commonly produced woody species; ninebark (Physocarpos opulifolius), pin oak (Quercus palustris) and swamp white oak (Quercus bicolor); were used in the study. All three of these species are native to much of the eastern U.S. Seedlings were planted and grown with seven different cool season vegetative treatments that were selected based on their biomass production and ability to suppress weeds.
Results from the two-year study note all of the species evaluated provided both short- and long-term weed suppression with minimal-to-no effect on woody plant growth and survival. For sites where weed pressure was high, annual covers may be very useful for suppressing weeds during the establishment year. But for the longer term, perennial grass covers may be more beneficial.
For more information on results of this NRCS study, click here.