Tuber Yield and Quality of Potatoes As Affected By Cover Crops and Nitrogen Fertilizer.

Nitrogen is a plant nutrient that contributes to growth and development of potatoes. Often, growers over-apply N fertilizer in potato production, an action which could affect tuber yield and quality of potato negatively. Suitable cover crop and N management could result in reducing N fertilizer requirement and enhance sustainable potato production. This research addresses N fertilization and the use of cover crops to improve soil fertility. An experiment was conducted at the research farm of the University of Massachusetts during the 2011-2012 growing season on a sandy loam soil. The treatments were arranged in a replicated factorial-split plot design in which four cover crops (no cover crop, daikon, peas, or rye) were combined with four N fertilizer applications (0,75,150, or 225 kg N ha^-1) and with Dark Red Norland and Superior potatoes as sub plots. Presence of cover crops significantly improved yield of potatoes compared with no cover crops.  Nitrogen fertilizer increased yield relative to no fertilization regardless of cover crop presence; however, application of 225 kg N /ha suppressed the yield. Dark Red Norland had a higher yield than Superior. Cover crops increased some nutrient concentrations in potato tubers compared with no cover crop, and Dark Red Norland accumulated a higher concentration of nutrients than Superior. In conclusion, a soil fertility practice that involves application of cover crops and 75 to 150 kg N/ha results in improved potato tuber yield and quality and reduces nitrogen fertilizer application, hence achieving sustainability.