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Free Online Tool Helps Farmers With Nitrogen Application Decisions

Free Online Tool Helps Farmers With Nitrogen Application Decisions
New decision tool helps farmers and crop advisors manage N for maximum yield, minimal environmental damage.

At the annual Integrated Crop Management Conference last week at Iowa State University, Chad Hart gave an interesting presentation on the "Usable to Usable" or U2U climate initiative. An Iowa State associate professor of economics and Extension grain marketing specialist, Hart is the Iowa project coordinator for the Corn Split N tool.

CORN SPLIT N: The "Useful to Usable" or U2U climate initiative has launched a new online decision support tool called Corn Split N. Farmers and crop consultants can use it to manage application of in-field nitrogen for maximum yield, efficient use of N and minimal effect on water quality.

A federally funded climate initiative, which includes Iowa State University, the U2U project has launched several new online support tools to help farmers cope with weather and climate variability. One of these new tools is a computer program to help farmers, agronomists and crop consultants manage the application of in-field nitrogen for maximizing crop yields and minimizing the effects on the environment.

The free tool, called "Corn Split N," is available for use in Iowa, Illinois, Indiana, Missouri and Kansas. 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.

U2U project team includes nine north-north central universities
The tool was developed as part of "Useful to Usable," or U2U, a USDA-funded research and Extension project designed to improve the resilience and profitability of farms in the Corn Belt amid a variable and changing climate. The project team includes 50 faculty, staff and students from 9 north-central universities with expertise in applied climatology, crop modeling, agronomy, cybertechnology, ag economics and other social sciences.

"Traditionally, farmers have applied nitrogen to the soil in a single pass either in the fall or in spring before planting," Hart notes. "However, research has shown that by splitting the nitrogen over two intervals, applying it once in the fall or spring when the soil is not saturated and the temperature is between 50 and 32 degrees Fahrenheit, and then a second time when the plants are in the ground and in most need of the N, this split application will ultimately lead to better results. Less fertilizer will be needed overall and not as much will be lost in runoff."


Less N will need to be applied, and runoff loss will be reduced
Nitrogen management of corn includes many factors. One is the timing of the application, which varies depending on weather and soil conditions. The Corn Split N tool's historical climate data is designed to assist farmers in pinpointing when nitrogen should be applied for best results.

Because the post-planting application must be done before the corn gets too tall, estimates of corn development stages based on location, selected planting date and accumulated corn growing degree days for the year also are factored into the tool. Growing degree day accumulations and associated corn growth beyond the current day are estimated based on the historical 30-year (1981 to 2010) average degree day accumulation for a location.

Hart says the Corn Split N tool helps farmers quantify the costs and benefits under average, worst and best case scenarios when doing a post-planting nitrogen application, even taking into account two passes of ground equipment in the fields.

Get results based on your planting and fertilization schedule
Farmers get customized results based on their planting and fertilization schedule, local costs and available equipment. A summarized fieldwork table and crop calendar which comes with this tool allows farmers to see how schedule adjustments might affect their ability to fertilize on time.

In 2015, the Corn Split N tool will be expanded to seven additional north-central states: Wisconsin, Minnesota, South Dakota, North Dakota, Nebraska, Ohio and Michigan.

To learn more, click here  or visit the U2U homepage.

Several new tools created to help cope with variable weather
U2U project partners are Purdue University, Iowa State, Michigan State University, South Dakota State University, University of Illinois, University of Michigan, University of Missouri, University of Nebraska, University of Wisconsin, High Plains and Midwestern NOAA Regional Climate Centers and the National Drought Mitigation Center. Linda Stalker Prokopy at Purdue is the U2U project director.


Corn Split N is part of the U2U suite of tools created to help farmers and ag advisors 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.

Other U2U decision support tools include:      
AgClimate View provides convenient access to customized historical climate and crop yield data for the U.S. Corn Belt. Users can view graphs of monthly temperature and precipitation, plot corn and soybean yield trends, and compare climate and yields over the past 30 years.

Corn Growing Degree Day allows users to track real-time and historical accumulations, assess spring and fall frost risk and guide decisions related to planting, harvest and seed selection. This innovative tool integrates corn development stages with weather and climate data for location-specific decision support tailored specifically to agricultural production.

Climate Patterns Viewer helps farmers and agricultural advisers assess how climate patterns in other parts of the world can influence local climate conditions and corn yields across the Corn Belt. The tool can help growers make more informed farm management decisions during different phases of the El Niño Southern Oscillation and Arctic Oscillation by relating historical events to associated precipitation and temperature impacts over the course of a year.

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