Technologies are currently available and are being further developed to determine the nitrogen (N) nutritional status of corn (Zea mays L.) for in-season applications of N fertilizer. The objective of this multi-year study was to compare relative leaf chlorophyll content (RC) using the SPAD meter with normalized difference vegetative index (NDVI) using the GreenSeeker sensor for determining in-season N recommendations for corn.  Four studies were conducted on Nicollet clay loam and Port Byron silt loam soils in southern Minnesota.  Treatments consisted of varying rates of N fertilizer applied for corn grown following corn and following soybean [Glycine max (L.) Merr.].  Corn grain yields responded to fertilizer N at all sites.  Regression analysis indicated relative chlorophyll content at V8 through R1 accounted for 64 to 96% of the variation in corn grain yield response to varying rates of N fertilizer for corn following corn, whereas NDVI at V7 through V9 accounted for 40 to 85%.  Leaf chlorophyll and NDVI were not as effective at predicting N status in corn following soybean.