Nitrification inhibitors slow the microbial conversion of ammonium-nitrogen to nitrate-N (nitrification), reducing the risk of loss through leaching or denitrification. This nitrification inhibitor practice specifically includes only nitrapyrin, the active ingredient in N-Serve, and applied with fall anhydrous ammonia. For this practice, anhydrous should be applied when soil temperatures are 50°F and cooling, and used with other best practices for applying anhydrous ammonia. (There is no water quality data on other nitrification inhibitor products, but the science assessment recognized the need for such information.)
Research shows a corn yield increase of approximately 6%, plus a nitrate-N loss decrease when using nitrapyrin with fall-applied anhydrous ammonia.