See more from this Session: Site Specific Nutrient Management: I
Wednesday, October 19, 2011: 10:35 AM
Henry Gonzalez Convention Center, Room 211, Concourse Level
Optimal nitrogen (N) fertilizer rate for corn can vary substantially within and among fields. Crop reflectance sensors offer the potential to diagnose crop N need and control N application rates at a fine spatial scale. Our objective was to evaluate the performance of sensor-based variable-rate N applications relative to a constant N rate chosen by the producer. Fifty-five on-farm demonstrations were conducted from 2004 to 2008. Sensors were installed on the producer’s nitrogen application equipment and used to direct variable-rate sidedress nitrogen applications to corn at growth stages ranging from V6 to V16. A fixed N rate chosen by the cooperating producer was also applied. Relative to the producer’s N rate, sensors increased partial profit and yield while reducing N use. Our results confirm that sensors can choose N rates for corn that perform better than rates chosen by producers.