Factors such as price and availability come into play when deciding on a nitrogen source, but anhydrous ammonia is favored. Anhydrous nitrifies more slowly than other products such as urea or UAN solution, so it’s preferred, especially in soils that are prone to nitrogen loss in wet conditions.
When it comes to planting after an anhydrous application, there is no exact “safe wait time” before planting. Your goal should be to make sure that the seed or root does not come into contact with the ammonia zone. If not applied at proper depths, anhydrous can potentially damage not just your corn seed, but also the roots and plant itself. Though most anhydrous disperses in the soil within 24 hours of application, it has a high pH and it takes very little free ammonia to cause corn seed injury. Shallow spring anhydrous applications near the seed have the highest chance of corn injury. Risk of anhydrous ammonia injury to your corn can still increase, even if you delay planting after application.
- If application is made in wet soils that then become dry, ammonia may become free to move up the injection track and closer to the root zone.
- If clay soils are wet at application, ammonia may move toward the soil surface at application due to sidewall smearing or lack of soil seal.
- If application is made in dry or coarse soils, a larger and more concentrated ammonia band may form.
Here is a checklist of recommended management practices to follow before making an anhydrous application:
- Make sure the soil is “fit” at application.
- Your anhydrous ammonia injection depth is 6” to 7”.
- Try waiting several days after an anhydrous ammonia application to plant.
- Apply the anhydrous ammonia at an angle to reduce the amount of corn that could be injured.
- Use your GPS guidance system and offset your anhydrous application from your future corn rows. Make sure that your equipment is working properly; nitrogen-burned corn has been found as a result of improper calibration.
Contact your local
Golden Harvest Seed Advisor with questions or for additional agronomic insights.
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