Impact of Fungicide Application on Nitrogen Use Efficiency on a Continuous Corn System with and without Fall Manure Application

Jason Louks

Traditionally in a continuous corn rotation a nitrogen use efficiency (NUE) of between 1.0-1.2 pounds of nitrogen is considered standard. Prior to using PSNT to determine sidedress nitrogen rates this was the NUE observed on this farm. Once soil nitrate testing was implemented into the nitrogen program, an improvement to approximately 0.9-1.0 pounds of nitrogen per bushel produced. Once the investment was made to gain the ability to apply the sidedress using variable rate technology the farm NUE improved to an average of 0.7-0.85 pounds of nitrogen per bushel while still being on a com on corn rotation.

While improvements in the nitrogen management program used on the farm have been observed, there remains room for continued improvement. While V5 fungicide application has been used on this farm, it has always been applied broadcast. By applying fungicide broadcast, much of the product is lost due it not hitting the plant. By applying the fungicide in a spray band with the sidedress toolbar, Central Advantage has shown that with less off target movement fungicide rates can be decreased while still showing a yield response. Fungicides are widely used on many crops to cure or protect the plant from disease. The focus of this project is to see if a healthier com plant, one with fungicide applied, utilizes nitrogen more efficiently than a plant with none applied. This will be tested on ground with and without fall manure applied.