Comparison of Ground-Based Active and Aerial Passive Sensors for in-Season Nitrogen Management.

Crop canopy sensors are one tool to help calculate an in-season nitrogen application rate in corn. When using crop canopy sensors corn growers have to decide between using an active crop canopy sensor and passive crop canopy sensor. The objective of this study were to determine the correlation between nitrogen management by remote sensing using a passive sensor and nitrogen management using proximal sensing with an active sensors, determine the effects of using a passive sensor or active sensor for in-season nitrogen management compared to a growers preferred nitrogen management in corn, and to increase awareness of tools available for nitrogen management. This study was conducted over 4 fields in central Nebraska during 2017. Treatments were arranged as field length strips in a randomized complete block design with 5 replication. Nitrogen was applied on the grower treatment strips by the grower using their preferred management strategy, on the active sensor strips with a high clearance applicator using Ag Leader OptRx^TM sensors, and the passive sensor strips with a high clearance applicator directed by multispectral imagery from an eBee SQ. Applications controlled via sensors were applied from V10 to V12 growth stage. Imagery from the eBee SQ was collected periodically throughout the season to monitor all treatments. Reflectance data was collected by the optRx^TM sensors during the side-dress application. The imagery and reflectance data will be compared as well as the nitrogen rates applied by the different methods. Yield data will be collected after harvest to further analyze the effectiveness of in-season nitrogen management with crop canopy sensors.