Nitrogen application rate is an important environmental concern due to the propensity of nitrate to move, thus increasing surface and ground water vulnerability to water quality impairment. A multi-year project was conducted in cooperation with producers to test in-season N management strategies as a means for improving application rates in Iowa cornfields. Our approach used low and agronomic pre N rates, in-season corn plant sensing with a Minolta SPAD chlorophyll meter to detect potential N stress, and providing farmers with an adjusted as-needed in-season N rate. Nitrogen treatments for corn following soybean were; 0 (control), 60 (reduced rate), 60+ (plus in-season N), 120 (agronomic rate), 120+ (plus in-season N), and 240 lb N/acre (reference) in replicated field-length strips at ten sites. Corn plants were sensed from V10 to R1 growth stages to determine N stress. In order to determine in-season N application, a previously determined calibration equation was used that related relative (normalized) SPAD readings to economic N rate. In-season N was applied with high clearance equipment close to the R1 growth stage. First year results (2004) demonstrated that N stress sensing successfully documented detection of N need and full yield recovery with the agronomic 120+ strategy (2 sites required in-season N); however, full yield recovery was not achieved with the 60+ strategy (8 sites required in-season N). The pre application rate of 120 lb N/acre, with confirmation of additional N need by plant sensing, appears to be a more desirable strategy than using a lower pre N rate. However, this requires further documentation with more years and sites.