Evaluating Benefits of Winter Annual Cover Crop Systems for Organic Sweet Potato in North Carolina

North Carolina is the second largest producer of organic sweet potatoes in the U.S., with a rapid 42% increase in acreage transitioning to organic from 2014 to 2016. Despite a steady demand for organic sweet potatoes, marketable yield often does not reach the yield potential for this region due to challenges in weed, insect and soil fertility management. Through farmer consultation soil borne pests such a wireworm and weed proliferation were identified as two areas of concern for organic farmers in North Carolina.


The use of cover crops for weed management has been effective in no-till row crops such as soybean by rolling and crimping to create a high biomass residue cover that suppresses weeds. Using a roller-crimper modified to work on raised beds this research will assess the viability of winter cover crops seeded onto autumn formed beds and terminated in the spring as effective tools for weed control as compared to the disruptive and energy intensive typical management practice of repeated cultivation. In addition, we will determine if there is a trade-off of including cover crops in rotation by potentially providing improved overwintering conditions for wireworms and if this translates into increased root damage and marketable yield losses. Lastly, by embedding increasing rates of organic nitrogen fertilizer in each cover crop treatment we will determine if this management practice requires modification to nutrient recommendations. The findings from this systems research approach will directly address the primary challenges facing organic sweet potato farmers with innovative management options.