Adapt-n for efficiency
Choosing a nitrogen rate for corn ahead of the growing season is like planning a Fourth of July picnic in January. There is no way of knowing if the weather will ruin your plans.
Harold van Es, a soil scientist and professor at Cornell University in New York, believes weather holds the key to managing nitrogen (N).
That belief led him and colleagues at Cornell to develop a new Web-based tool called Adapt-N that accounts for field-to-field and year-to-year variability in the availability of nitrogen in the soil. It's a form of adaptive management that enables growers to adjust rates from year to year based on local conditions, especially weather conditions.
“Corn N fertilizer needs cannot be predicted accurately at the beginning of the growing season due to weather variability during the critical period in spring,” says van Es. “Excessive precipitation causes soil N losses through leaching and denitrification, resulting in higher supplemental N fertilizer needs and increased pollution.”
Research shows the amount of nitrogen needed by a corn crop can vary by 100 pounds per acre or more from one year to the next.
Jeff Melkonian is a senior research associate at Cornell and a member of the team who developed the Adapt-N tool. He says, “In warm weather, nitrogen mineralizes faster from organic matter in the soil to become available to the corn, while the opposite is true in colder weather. In a drier spring, nitrogen mineralizes and remains in the root zone where the corn can take it up, while in a wetter year, the nutrient may leach out of reach of the crop roots.”
A third team member is Bianca Moebius-Clune, an Extension associate at Cornell. She says, “The Adapt-N tool provides growers with more precise, field-specific nitrogen recommendations based on the impact of early-season weather.”
It was beta-tested on a few farms in New York and Iowa in 2010 and 2011, and it will be used in additional states in the Northeast and Midwest this year.
“The Adapt-N tool represents a new approach in decision management by combining the use of the precision nitrogen management (PNM) model with the most up-to-date high-resolution climate data,” says Melkonian. “It involves advanced computational methods that can be employed through a relatively simple Web interface.”
The Adapt-N tool provides in-season nitrogen recommendations based on model simulations of soil N dynamics and corn nitrogen uptake. It was developed as part of the Computational Agriculture Initiative, supported by a special grant from USDA-NIFA.
Adapt-N is a Web-based decision tool that links to daily high-resolution climate data (on a 3-mile grid) made available by the Northeast Regional Climate Center. It was designed to account for daily weather influences and expected economic yield to calculate sidedress N recommendations for individual fields.