Online Tools

Nitrogen Calculator

The Split Application MRTN (Maximum Return to Nitrogen) creates a Nitrogen Management System based upon University of Illinois research and guidelines. It provides a reliable, responsible, and defensible nitrogen recommendation that minimizes environmental impact of nitrogen use by optimizing harvest yields and maximizing nitrogen utilization, minimizing residual N that may escape from the site of application.

Nitrogen Rate Calculator (MRTN)

This web site provides a process to calculate economic return to N application with different nitrogen and corn prices and to find profitable N rates directly from recent N rate research data. The method used follows a newly developed regional approach for determining corn N rate guidelines that is being implemented in several Corn Belt states.

Late Season Nitrogen Test

Nitrogen Fertilizer Recommendations for Corn in Iowa - PDF

This pamphlet replaces all earlier guidelines for using the late-spring test for soil nitrate and all previous nitrogen fertilizer recommendations based on corn yield goals and credits for N supplied by legumes and animal manures.