Use the Correct Nitrogen ‘Stabilizer’ to fit your Needs (05/19/22)
I dislike the term ‘stabilizer’ to define an additive intended to change the susceptibility of nitrogen fertilizers to loss. Originally it was used to help market N-Serve™ (originally Dow, now Corteva Agriscience) in the 1970’s when it was introduced. Now it appears that people throw the term around to describe any effect of product on nitrogen dynamics. The following is a brief description of use of different classes of nitrogen additive, amendments. For a far more detailed description, see the NDSU circular Nitrogen Extenders and Additives https://www.ndsu.edu/fileadmin/soils.del/pdfs/Nitrogen_Extenders_and_Additive_for_Field_Crops_2017.pdf
Nitrification inhibitors-
Nitrification inhibitors are mostly used in the fall with urea and anhydrous ammonia to keep the ammonia-based fertilizer in the ammonium form longer in the soil, and reduce the rate of conversion to nitrate, which is subject to leaching and denitrification. Two proven chemistries act to delay and reduce the rate of nitrification. One is nitrapyrin (N-Serve, Instinct™ (Corteva Agrisciences), others). The other chemistry for delay and reduction of nitrification is DCD (dicyandiamide). These chemistries do not stop nitrification. They only delay and reduce the rate of conversion.
Urease inhibitors-
The oldest and most researched urease inhibitor is NBPT, which was the active ingredient in the original Agrotain™. Now, NBPT is present in many products, but for use to be effective it should be used at the same rate of product to urea, or product to UAN (urea ammonium nitrate solution) as Agrotain Ultra™ (Koch Industries, Wichita, KS). The active ingredient NBPT, if used at the proper rate, is completely effective for about 10 days in stopping the conversion of urea to ammonium/carbon dioxide by soil-active enzyme urease. If the temperature is hot, this effectiveness may be for a shorter time, and will be for a longer time under cooler conditions.
This spring, when field season begins in earnest, everyone will want fertilizer applied the same day. It is not possible. Likely most acres will receive a urea application after planting. Under those circumstances, application of urea treated with NBPT will be necessary to prevent ammonia volatilization, especially when there is surface residue present and/or the soil pH is greater than 7. When soil pH is under 6, ammonia loss is less likely. However, unless a grower knows through zone sampling a field that soil pH is all acidic, there is a strong possibility that a major portion of any field has pH greater than 7.
Use the nitrogen additive that will be of greatest benefit to your situation.
Extension Soil Specialist
701-799-2565
