|SCHARF, PETER - University Of Missouri|
|SHANNON, KENT - University Of Missouri|
|Sudduth, Kenneth - Ken|
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/21/2011
Publication Date: 10/16/2011
Citation: Scharf, P., Shannon, K., Sudduth, K.A., Kitchen, N.R. 2011. Sensor-based nitrogen applications out-performed producer-chosen rates for corn in on-farm demonstrations [abstract]. ASA-CSSA-SSSA Annual International Meeting, October 16-19, 2011, San Antonio, Texas. 358-10.
Technical Abstract: 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.