FARMERS HAVE a new tool to help deal with the recent sharp increases in nitrogen prices. New nitrogen rate guidelines for Illinois corn growers help them apply economics to the decision on nitrogen rates. The guidelines allow growers to apply nitrogen on corn within a defined range of rates that is based on calculations using research data from more than 250 nitrogen rate trials in Illinois. Recommended ranges change when the price ratio between nitrogen and corn changes.

For more information, contact Emerson Nafziger, U of I Extension crop scientist, at 217/333-4424.

Iowa corn producers can calculate the economic return to nitrogen application using a new regional Web-based tool located at the Iowa State University Extension agronomy Web site. The Corn Nitrogen Rate Calculator follows a newly developed regional approach for determining corn nitrogen rate guidelines. The Web site includes an animated demonstration of the calculator.

The site calculates the new economic return to nitrogen application and finds the maximum return to nitrogen rate directly from recent research data. The site includes nitrogen rate trial data for Iowa, Illinois, Minnesota and Wisconsin that had an adequate number of research trials available for corn following soybean and corn following corn. These trials were conducted with spring, sidedress or split preplant/sidedress-applied nitrogen, and the sites were not irrigated.

Using the online calculator, producers can calculate returns for one set of nitrogen fertilizer and corn grain prices, or multiple prices for the state and rotation in which they are interested. Visit extension.agron.iastate.edu/soilfertility/nrate.aspx.