Effect of Controlled-Release N Fertilizer on Corn Grain Yield

We are continuing to look for technology that will enable us to manage nitrogen (N) fertilizer efficiently. Past research has studied the effect of nitrification inhibitors, sulfur coating, and time of application on N-use efficiency. Recently a controlled-release polymer-coated urea material (ESN) has become available. Evaluation of the material in terms of efficiency of use on corn is necessary to help crop producers decide if the extra cost of ESN can be recovered either by applying less material or by producing higher yields at current N rates. The objective of this study is to evaluate the effect of spring applications of ESN and urea on a corn-soybean cropping system