Using Aerial Imagery in Conjuction with Nitrogen Calibration Blocks for Continuous Monitoring and of Nitrogen Stress.

Nitrogen (N) fertilizer  is often the most limiting nutrient in corn production. Often N is all applied before planting, which can be very inefficient due to various loss processes. Previous research has shown the benefits of delayed application of N with rates determined through the use of active crop canopy sensors. These sensors have the ability to detect nitrogen stress in a corn crop that is undetectable to the human eye. Methods have been developed to fertilize later in the season with a variable rate application. This normally is one-time application with no ability to correct for later growing conditions. These methods also require physically driving through the field to acquire data. Nitrogen rate calibration treatment blocks were set up in a cooperating producer’s field in Pierce County, Nebraska. Blocks consisted of differing rates of N applied at different growth stages to simulate a variable rate application. Using aerial imagery, differences in response to N were measured. This method allowed for continuous monitoring of  treatments throughout the time of highest N demand by the crop. Results from the first year of study will have been analyzed and reported.