Corn on Corn Requires Careful Nitrogen Management

Since the immobilization of nitrogen is a potential hurdle, continuous corn is more subject to nitrogen stress than corn in a rotation with soybean. “Soil microbes use nitrogen as an energy source to break down residue,” says Mark Licht, Ph.D., an assistant professor and cropping systems specialist with Iowa State University Extension. “Continuous corn often requires 30 to 50 pounds per acre more nitrogen than corn following soybeans.”

Applying more nitrogen requires careful management. “It’s important to feed your corn crop at key points during the growing season,” says Andy Heggenstaller, head of agronomy at Syngenta Seeds.

“Continuous corn often requires 30 to 50 pounds per acre more nitrogen than corn following soybeans.”

The process can start with stabilized nitrogen applied during the fall, says Blake Miller, a Syngenta agronomic service representative in Illinois. Nitrogen applied preplant and then side-dressed during the growing season also helps increase plants’ nitrogen-use efficiency in a continuous corn system. “That’s what helps you beat yield drag,” Miller adds.