The Purdue University-led Useful to Usable climate initiative is offering a new online tool to help farmers and farm advisers better manage the application of nitrogen fertilizer for maximum crop yields and minimum environmental damage.

The free tool, called Corn Split N, combines historical weather data and fieldwork conditions with economic considerations to determine the feasibility and profitability of completing a post-planting nitrogen application for corn production. Now available for use in Illinois, Iowa, Indiana, Missouri and Kansas, it will be expanded in 2015 to include seven North-Central states – Wisconsin, Minnesota, South Dakota, North Dakota, Nebraska, Ohio and Michigan.

Farmers traditionally have applied nitrogen fertilizer to the soil in a single pass, either in the fall or in the spring before planting. But Ben Gramig, Corn Split N project team member and Purdue associate professor of agricultural economics, said agronomic recommendations are to “split-apply” the nitrogen twice – once in the spring at planting and then a second time after the corn plants have emerged from the ground so that they can use the fertilizer most effectively.

“This timing of fertilizer application requires less fertilizer, can improve yields and limit fertilizer losses due to leaching and runoff,” Gramig said.

He explained that nitrogen management of corn includes the timing of the application, which is limited by weather and soil conditions. Corn Split N uses historical climate data and days suitable for fieldwork to assist farmers in evaluating when nitrogen can be applied for best results.

Farmers get customized results based on their planting and fertilization schedule, costs and available equipment. In addition, a summarized fieldwork table and crop calendar make it easy to see how schedule adjustments might affect their ability to fertilize on time.

Corn Split N is part of the suite of tools of Useful to Usable, or U2U, created to help farmers and agricultural advisers manage increasingly variable weather and climate conditions across the Corn Belt. The tools incorporate historical climate data to help inform purchasing, marketing and activity planning throughout the growing cycle. Data in all tools are updated on a regular basis, even daily in some cases.