In 2001, N fertilizer prices nearly doubled as a result of increased losses due to surface runoff range between 1 and 13%natural gas prices. This was further troubling when considering that
the world N use efficiency (NUE) in cereal grain production averages only 33%. Methods to improve NUE in winter wheat (Triticum aestvum L.) have not included high spatial-resolution management based on sensed plant growth properties nor on midseason prediction of grain yield. Our objective was to determine the validity of using in season estimates of grain yield (INSEY) and a response index (RI) to modulate N at 1-m2 spatial resolution.