Nitrogen inhibitors, often referred to as stabilizers, are increasingly used by farmers looking to protect their fertilizer investments and maintain yields amid increasingly erratic weather.
There are two primary types of nitrogen inhibitors in the marketplace today: urease inhibitors and nitrification inhibitors.
Nitrification inhibitors such as nitrapyrin, DCD, and pronitridine have been developed to delay the conversion of nitrogen fertilizers into nitrate, according to Fabian Fernandez, University of Minnesota Extension nutrient management specialist.
“The reason we want to delay transformation to nitrate is that nitrate can leach below the root zone or be denitrified if there is excessive precipitation,” Fernandez reports.
Urease inhibitors such as NBPT and NPPT delay the conversion of urea into ammonia. “We want to prevent nitrogen transformation to ammonia as this too will end up in the environment and not available to the crop. In this case, though, the loss happens as ammonia goes off as a gas to the atmosphere,” he says.
As the 2026 season gets underway, here are two key reasons to consider using a nitrogen inhibitor:
1. Maximize Nitrogen Efficiency
Inhibitors delay the conversion of ammonium-N to nitrate-N, which reduces nitrogen loss via leaching and denitrification, increasing N availability for crops and boosting yields by 5% to 12%, according to Bob Nielsen, Purdue University agronomist and professor emeritus.
Furthermore, because inhibitors slow down the nitrogen conversion process the nutrients stay in the root zone and available to crops longer – up to eight weeks depending on the product used, according to Corteva Agriscience.
2. Keep Nitrogen In The Field
Early in the season, heavy rains and warming soil temperatures can contribute to significant nitrogen loss. With spring applications, research shows soil can lose more than 20% of its total nitrogen after just one or two rain events, according to Heather Vosburgh, nitrogen stabilizer strategic account manager, Corteva Agriscience.
The concern for potential N runoff is why Tyler Wiltfang, a fourth-generation farmer, near Oregon, Ill., says he uses an inhibitor in early spring, prior to planting corn.
“Some of our fields are very close to a creek, and we don’t want that [nitrogen] going other places,” says Wiltfang, who grows corn and soybeans on the same land his great grandfather bought in 1929.
“It’s important to be thinking about the environmental impact, because we have to take care of the ground to grow our crop,” Wiltfang adds. “If the soil isn’t up to par, and we’re not doing our part, we’re not going to have a good crop using a nitrogen stabilizer, such as Instinct.”
With meteorologists predicting an active weather pattern across the Eastern Corn Belt this spring delivering excess moisture that could delay early planting, farmers in those areas might want to be prepared to use an inhibitor.
When To Pass On Using An Inhibitor?
There’s at least one scenario when you don’t need to use a urease inhibitor — when you make a broadcast application of urea that is immediately incorporated by tillage at least 2” in the soil, Fernandez reports in this online video and article.
“If you were concerned about nitrogen loss from a pre-plant application, I would not use urea-ammonium nitrate (UAN) and include a nitrification inhibitor to protect the investment,” he says. “While the nitrification inhibitor will provide protection, 25% of the application is already nitrate in this fertilizer source and the inhibitor will do nothing to protect nitrate from leaching or denitrification loss. It would be a much better idea to use the inhibitor with a urea application.”
On the other hand, Fernandez says using a urease inhibitor when urea is surface-applied in a high crop-residue field, or a nitrification inhibitor or polymer-coated urea in fields or portions of fields that tend to be wet, is most likely to increase the chance that you see a benefit from your investment.
Agronomic specialists like Fernandez emphasize that nitrogen stabilizers are not stand-alone solutions. They are most effective when integrated into a broader nitrogen management strategy that includes realistic yield goals, soil testing, attention to soil type and drainage, and thoughtful decisions on application rate and timing.
