Nutrient loading to freshwater systems is a key environmental issue concerning agriculture in the Upper Mississippi Watershed (UMW). In Illinois, EPA suggested nutrient reductions are being met by wastewater treatment and industrial facilities, but not by agricultural producers. Solutions are needed to reduce nutrient losses from agricultural fields. In the tile drained systems of the UMW, edge-of-field practices are not sufficient to meet nutrient reduction goals. In-field practices such winter cover crops are a promising tool for agriculture to meet nutrient reduction targets. Pennycress, a new winter cash crop being domesticated for biofuel and animal feed purposes, may help meet nutrient reduction goals while also providing economic incentive to producers. Our objective is to quantify how pennycress may help the UMW meet nutrient reduction targets as a winter cash crop. Using replicated and independently drained 0.8ha plots we assessed the potential for pennycress to immobilize nutrients in-field and in subsurface drainage systems. Our results demonstrate that pennycress is an effective short-term, winter to spring nutrient sink. Pennycress use resulted in up to 5-fold reductions in soil porewater nitrate-nitrogen relative to fallow conditions and significant reductions in soil nitrate-nitrogen relative to fallow conditions. Additionally, pennycress reduced subsurface discharge, resulting in near zero nutrient export to freshwater systems. We show that by utilizing in-field nutrients pennycress may effectively eliminate nutrient export to freshwater systems during the winter fallow period of the UMW. The use of pennycress as a short-term nutrient sink will assist the UMW in meeting EPA nutrient reduction goals.