Nitrogen (N) is typically one of the largest corn fertilization expenses. Nitrogen application is critical because it significantly improves corn yield in many crop rotations. When choosing N rates, producers need to carefully consider both achieving most profitable economic return and advancing environmental stewardship.

In 2004, university agronomists from the Corn Belt states began discussions regarding N rate use for corn production. The reasons for the discussions centered on apparent differences in methods for determining N rates across states, misperceptions regarding N rate guidelines, and concerns about application rates as corn yields have climbed to historic levels. An outcome of those discussions was an effort with the objectives to:

▪ develop N rate guidelines that could be applicable on a regional basis and

▪ identify the most profitable fertilizer N rates for corn production across the Corn Belt.

This publication provides an overview of corn N fertilization in regard to rate of application, investigates concepts for determining economic application rates, and describes a suggested regional approach for developing corn N rate guidelines directly from recent research data.