Determining the most economically optimal N rate can be done using an N rate calculator. Keep in mind this does not account for carryover N, he adds. With this year's wet spring, it's unlikely that much N will be carried over. Consider applying only a portion of the total nitrogen needed in the fall and the rest in the spring.


"Because more acres are planted to cornfollowing corn, there is increased interest in corn residuemanagement," Fernandez says. "Don't apply N to increase residue breakdown. Research has shown no benefit in this."


When making N application decisions, consider the risks and benefits of fall N application. Overall, research on N application timing has shown that application in the spring, close to the time of rapid N uptake, maximizes yield because there is less chance for leaching or denitrification. However, late-fall application of some N sources is adequate, especially for medium- to fine-textured soils where cold winter temperatures prevail and early springs are not excessively wet and warm.


"If you don't like taking big risks, but a fall application makes sense, it may be better to apply part of the N in the fall and wait until spring to apply the rest," Fernandez says. "This approach is like buying an insurance policy. It gives peace of mind but costs money, and you can never be certain whether the investment will pay off."