Wheat yield population response to variable rate N fertilization strategies using active NDVI sensors

The goal of precision agriculture is to vary inputs to match the spatial yield potential of a site, thus minimizing input cost while maximizing economic return to the producer. Historically, the scale of precision fertilization has been limited to the size of the applicator, but innovations have made it possible to variably apply fertilizer on a 0.56 m² basis using field size equipment and active, realtime NDVI sensors. An experiment was conducted in Kentucky, USA to evaluate the effect of different nitrogen fertilization strategies on wheat (cv. Declaration) yield and yield population across a variable landscape. There were four treatments with four replications. Nitrogen fertilizer application was varied on a 0.56 m² grid based on canopy NDVI for two of the treatments, while uniform applications of two rates were the other two treatments. Results indicated that the imposed treatments did not only affect the average yield, but also affected the characteristics of the yield populations and the spatial N use efficiency.