Variable weather conditions make it difficult to predict the nitrogen (N) requirements for a crop at planting. It may be advantageous, therefore, to reduce N application at planting and provide supplemental N in-season as needed. RapidEye's new satellite constellation might make it practical to regularly monitor the N-status of wheat from space throughout the season, because in addition to traditional spectral bands it will have a broad band (690-730 nm) in the red edge region, which has been shown to be particularly sensitive to leaf nitrogen. For this study, images of 30 wheat and barley fields were acquired at six occasions during a single growing season with an aircraft mounted specially built DuncanTech sensor that included a red edge band. One of the most promising algorithms to assess spatial variability of N-status was: [y = (NIR-Red Edge) / WDVI], where NIR and Red Edge stand for reflectance in the respective bands and WDVI for weighted difference vegetation index. In order to be able to detect an upcoming N deficiency at an early stage, N ramps with four to six N levels were put in place in the fields. Most fields were affected by the extremely dry weather conditions in late June and July, and N demand was therefore limited. It was possible, however, to reduce N rates by up to 50 kg N/ha in some fields.