Four fertilizer management systems for irrigated potatoes were compared in terms of their effects on yield, shallow groundwater and soil nitrate-N (NO3). Preliminary results from the first two years of a four year study are reported here. The high N treatment (300) did not increase yield relative to the three other treatments. These treatments applied the recommended rate as a single application (200), a split application (SPLIT) and a split application with supplementary N supplied through fertigation (FERT). The water table under all treatments rose while potatoes were growing and the NO3 content of shallow groundwater also increased. Under the 300 treatment, NO3 in shallow groundwater continued to increase in the year following potato production when canola was grown. Nitrate accumulated in the soil profile in all plots during potato production but profile NO3 decreased under canola.