N Inhibitors tips
If you want to use nitrification inhibitors, set realistic expectations. Here's how.
Since nitrogen (N) keys corn production, it’s important to keep your fall- and spring-applied N in the root zone and avoid as much loss as possible. Nitrification inhibitors can be a tool to help you do that by slowing the conversion of ammonium to nitrate, keeping N available to the crop longer. Here are three factors that Extension specialists recommend if you are using or considering using a nitrification inhibitor.
1. View Inhibitors as insurance.
Nitrification inhibitors don’t guarantee an increase in yield, says Dave Franzen, North Dakota State University Extension soil specialist. Instead, view inhibitors as insurance against excess water.
“It’s an insurance policy, so the loss doesn’t occur,” he says. “It’s not a guarantee you’ll get a yield increase. It’s just going to slow the nitrification process so losses are not as great or don’t occur as readily.”
Research shows nitrification inhibitors do as intended, says Franzen. “You aren’t eliminating the nitrification, but you are ensuring you’ll have more (N) available for your crop,” he says.
Fabian Fernandez, University of Illinois Extension soil specialist, recommends you consider using nitrification inhibitors for fall applications. There’s a greater chance of seeing a benefit from the inhibitor because the N fertilizer is applied before the plant will use it.
Fernandez encourages you to view the application in terms of risk. You may not see a difference if the inhibitor is used in applications close to planting. He does not recommend the use of inhibitors with sidedress applications. N applied in the fall or early spring has higher potential for N loss than late-spring applications.
“With spring applications, you are closer to planting, so you may or may not see the benefit; it’s a risk-management strategy,” says Fernandez.
2. Factor in the weather.
Results from nitrification inhibitors are largely reliant on Mother Nature. Yield increases may not occur in a dry year when N loss risks are low.
“In springs where the conditions aren’t favorable for N loss, we haven’t seen much of a difference,” says Fernandez.
However, in years favorable for N loss and when N is applied early, you’ll see more results from using inhibitors.
“In studies where there has been significant water and losses due to leaching, there have been yield increases in those situations,” Franzen says.
The purpose of nitrification inhibitors is to reduce the amount of nitrification occurring. However, nitrification itself isn’t the problem, explains Fernandez, because plants use nitrate.
N loss can occur through either denitrification or leaching (when soils are saturated with water). “Either way, we lose nitrogen. That’s why we see the benefit with N-Serve. It reduces the amount of nitrification that occurs,” says Fernandez.