Investigating in-season cover crops for reducing nitrate loss to groundwater below potatoes

In agricultural production, nitrogen fertilizers and other nutrient sources (e.g., manure, bio-solids, and legume credits) are valued for their ability to increase crop yields. However, some nitrogen leaches to groundwater as nitrate; at which point it becomes a drinking water contaminant for municipal and private water systems and increases nutrient export to freshwater ecosystems. Potatoes are particularly challenging for groundwater quality since they have high nitrogen fertilizer rate recommendations and are commonly grown on excessively drained soils where water and nitrate can easily leach past the root zone of plants. Even when following recommended rates, concentrations above the drinking water standard for nitrate are expected. Cover crops are increasingly being investigated for the potential to help improve water quality and soil health. Studies have been performed investigating the impact of cover crops grown prior to or following potato; however little research has been performed that investigates water quality benefits or yield effects when cover crops were inter-seeded while growing potatoes. This proposal seeks to investigate the feasibility of utilizing in-season cover crops in potato production to reduce nitrate leaching losses to groundwater. The objectives are to quantify the potential water quality benefits of cover crops inter-seeded with potato to reduce nitrate losses to groundwater and investigate positive and/or negative interactions of cover crops on potato yield, quality, and harvestability.