This web-based decision support tool is designed to help farmers and farm advisors understand the risks and benefits of using post-planting nitrogen (N) application for corn production. The Corn Split N tool combines historical weather and fieldwork data with economic considerations to determine the feasibility and profitability of completing a second (split) N application within a user-specified time period. The tool is currently available with local weeky observed historical data for Illinois, Indiana, Iowa, Kansas, and Missouri, and with estimated weekly values in Michigan, Minnesota, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin.

This tool may help users with decisions that:

• Increase corn yield,
• Reduce nitrogen costs,
• Reduce nitrogen losses to the environment, and
• Affect the likelihood of completing in-season fieldwork.

With the Corn Split N tool, users can quantify the costs and benefits of post-planting nitrogen applications for their farming operation to help both the bottom line and the environment.

The tool is an intregal part of the Useful to Usable (U2U) Crop Decision Dashboard, an online resource focused on informing agricultural decisions in the midwest.

Why Split Apply Nitrogen?

Farmers traditionally apply nitrogen to the soil in a single pass during either the fall or in the spring before planting. However, early nitrogen application can result in significant losses due to weather factors (e.g., warm, moist soils). Research has shown that a split application of nitrogen—one application in the fall or around the time of planting and a second application after planting when there is the greatest demand for N from the crop—can reduce total nitrogen use (savings to the farmer) and/or reduce nitrogen loss to the environment (savings to society).

There are some risks involved with a split nitrogen application strategy. Greater costs are incurred because two passes through the field are required. Additionally, the second application (if conducted using ground application equipment) may be hindered due to weather conditions. If soils are too wet during the time when a second application of nitrogen is needed, insufficient nitrogen may result in lower yields. With the Corn Split N tool farmers now have a way of quantifying the costs and benefits of post-planting nitrogen applications.