Cover crop residue and organic mulches provide weed control during limited-input no-till collard production

Conservation tillage is an effective means to suppress weeds, improve soil quality, and thus enhance food security. However, limited-input producers are reluctant to adopt these practices because of inadequate weed suppression without herbicide use. The purpose of this study was to demonstrate that effective weed control and stable collard yields can be achieved through high-biomass producing cover crops with organic mulches. This system was employed for three consecutive years (2005 - 2008) using forage soybean summer cover crop and mimosa, lespedeza, wheat straw, and a no-mulch control. Mulch use was successful in suppressing broadleaf and sedge weeds over the course of the experiment and demonstrated grass weed suppression after three years. Collard yields were not affected by mulch use and averaged 17,863 kg/ha. The results of this study strongly suggest that limited-input producers may incorporate mulch use in conservation tillage systems without affecting crop yields.