Determination of the Effect of Nutrient Management Plans on Nitrate Concentrations in the Soil and Water Below the Root Zone in Commercial Potato Production.

Abstract

Nitrate leaching from research and commercial potato rotations was evaluated using stainless steel zero tension lysimeters, tile drainage and soil samples. The effect of nutrient management versus conventional fertility on marketable potato yield was also investigated. Neither the lysimeters nor the tile lines were able to detect a significant treatment effect on the concentration of NO3--N in collected water samples. However, trends in the NO3--N concentration conformed to nutrient application. Soil samples detected similar trends in soil NO3--N at the research site. Nutrient management fertility had no significant effect on marketable potato yield or soil NO3--N at the commercial sites. A significant crop effect on soil NO3--N was detected. Fall soil samples indicated excess NO3--N in the soil following potato harvest suggesting an overuse of nitrogen fertilizer.