In areas across the country that are experiencing delayed planting due to weather conditions, growers whose normal practice includes applying anhydrous pre-plant likely won’t want to wait too long to get into the field. The question then becomes how soon can corn be planted after applying anhydrous pre-plant without causing injury?
When anhydrous is applied, it forms into a band about 5-6? in diameter. If there is a lot of moisture, the band could be slightly smaller, but in drier, coarse-textured soil the band could also be larger.
Ideally, it’s best to wait at least a few days to a week after applying anhydrous before planting, but considering the recent weather conditions, that might not be realistic.
Here are some considerations for minimizing the impact of injury from anhydrous: [factoid]Ideally, wait a few days to a week after applying NH3 before planting, but this might not always be realistic.[/factoid]
1. Depth of injection. This is probably the most important factor to keep in mind. Make sure you inject at least seven inches deep to keep that band as far away from young seedling roots as possible.
2. Apply at an angle. This minimizes the intersect of the corn row with the anhydrous injection band.
3. Ensure good closure. Make sure you get good closure behind the knife to minimize the expansion of the anhydrous band.
4. Reduce your rate. Cut your rate to 100 lbs or less. You can always come back and side dress with 360 Y-DROP® Sidedress or another method.
5. Ensure proper calibration. Make sure you know that each knife is injecting the right rate. Don’t assume your application equipment is applying the same rate to every row.
The longer the delay, the more tempting it becomes to plant as quickly as possible. If this desire comes close after applying anhydrous, in can increase the risk of injury to the crops. In a perfect world it is still best to wait a few days or more to plant after application but implementing these few simple practices can help minimize the risk.