What is in this article?:
- Yields from N forms are very similar, studies show, although anhydrous ammonia is the most stable form. Apply your chosen form as close to plant uptake as your operation allows.
- Preplant spring anhydrous ammonia is the best bet for reducing N loss.
- Manure showed the highest economic gain over any other N form.
- Sidedressing as a primary fertilizer source has big advantages in wet years when it’s questionable whether a crop will be planted.
Your choice of nitrogen (N) comes down to when you apply, your equipment, handling preferences, availability and costs. And the weather wild card often determines whether you’re happy with your choice in any given year.
Your N-loss risk hinges on timing, source and rainfall, says Peter Kyveryga, senior research associate with the Iowa Soybean Association (ISA) On-Farm Network. Anhydrous ammonia is the most stable form, since it takes longer to convert to nitrate, he says. “Some sources, like liquid N, already contain nitrate, which can be lost quickly in heavy rains after application. But extended wet soil conditions hasten N loss in any form. The closer you can apply N to the time of maximum corn uptake, the better.”
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