The use of canopy sensors to manage nitrogen (N) fertilizer is well-suited to irrigated corn – fertilizer applied in-season can be easily irrigated into the soil if rain does not soon follow fertilization. However, sensing of crop N status can be complicated if the crop is also under water stress, as differentiation of water and N stress, or other stress for that matter, may be challenging. This presentation will focus on research to simultaneously measure N and water status of a crop, and accurately apply rates of N to optimize profit in irrigated environments.