ADEL, Iowa – In mid-December you may think a lot of fieldwork has wrapped up. That might be true in a more typical year with more snow cover, and although forecasts this week are below freezing statewide, one central Iowa farmer was racing on Friday to save time next spring.
Anyhdrous ammonia is a common agricultural chemical, applied as a gas beneath the soil, where it bonds to soil moisture. There, bacteria convert it into nitrates that plants can use.
To prevent that conversion from happening in the fall, the soil should be between 50 and 32 degrees when anhydrous ammonia is applied, like Lowell Garrett of Garett Farms in Adel did on Friday. He says when it comes to fall fertilizer, timing is everything.
“We like to do as much as we can in the fall to eliminate compaction, and the time factor in the spring,” Garrett explains. “That way we don’t have to do this in the spring, we can do it now, in the fall. So it’s a big bonus, you might say, if you can get her done in the fall.”
When ammonia is converted into nitrates, it becomes more likely to contaminate groundwater, if it’s displaced before plants can make use of it. Garrett says the goal, in the fall, is to avoid that.
“20 years ago, it was $250 a ton,” he says, “and today, it’s from $700-$800 a ton. So, it’s a big thing. I mean, we sure don’t want to waste any of it.”
Nitrification inhibitors are one type of nitrogen stabilizer, which stop bacteria from converting anhydrous ammonia into plant-ready nitrates. At the cost of $13 per acre, Garrett also applied a nitrification inhibitor to his field, and says the price tag on fertilizing this fall has some farmers rethinking their planting intentions for next year.
“It will affect some planting decisions,” says Garrett. “There will be less corn-on-corn, just because of the financial part of it, with corn being in the $3 area. It’s greatly going to reduce that, I would think.”
To hear more about applying anhydrous ammonia in the fall, click the audio player above this story.
