As you assess your needs and plan your fall nitrogen application program, especially those applications using anhydrous ammonia and UAN, keep these tips in mind to maximize yield and minimize loss.
1. Apply at the Right Time
Nitrification is the conversion of ammonium to nitrate, making nitrogen more vulnerable to loss. The goal is to keep nitrogen in the ammonium form as long as possible. Nitrification is a microbiological process that slows at lower soil temperatures, but does not completely stop, even in cold temperatures.
Delaying fall applications until the 4-inch soil temperature has fallen below 50 °F can help keep nitrogen in the ammonium form longer to minimize loss. This is called the safe anhydrous date and is a reference point at which the soil would remain below 50 °F. This date can vary based on seasonal characteristics of a location.
2. Select the Right Nitrogen Source
Anhydrous ammonia is a good fertilizer source for fall applications on acres that will be planted the following spring. While anhydrous is an ideal nitrogen source, there is still a risk of nitrogen loss, so it is best practice to utilize a nitrification inhibitor. A nitrification inhibitor can help slow the conversion of ammonium to nitrate, which is key to preventing nitrogen loss — ammonium will bind to the soil whereas nitrate can move with water and is prone to loss through leaching and denitrification.
3. Choose the Right Protection
A fall application can help save time, allow for flexibility in the spring and is more economical — but it also carries an increased risk of nitrogen loss. To protect a nutrient investment and boost efficiency, growers should utilize enhanced efficiency fertilizer (EEF) products such as CENTURO®, a next-generation nitrification inhibitor for anhydrous ammonia and UAN.
Featuring a patented active ingredient, CENTURO offers highly effective below-ground nitrogen protection and unequaled flexibility in an easy-to-handle solution that is noncorrosive to the metals used in UAN and anhydrous ammonia equipment.
4. Split Applications
Fall applications of nitrogen can help take pressure off spring field work, allowing for more timely planting. However, fall applications are subject to greater risk of loss due to abnormal weather. In addition to using EEFs, splitting the nitrogen application between fall and spring can also help reduce this risk of loss. Consider applying 25-40 percent of the total nitrogen after crop emergence, when the crop is actively using nitrogen to drive rapid growth.
When it comes time to apply, remember that a sound nitrogen management system will lead to increased efficiency and profitability.
To learn more about managing nitrogen this fall, contact your KAS representative today.
*Caution should be taken when applying on frozen ground or snow-covered soils where there is a heightened risk of nitrogen losses.
Always read and follow label instructions. CENTURO is not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state.