As harvest is starting to wrap up in Iowa and the cooling temperatures are making their appearance right in time for fall activities, it’s time to think of our next field operation, anhydrous ammonia. Anhydrous ammonia is an effective nitrogen fertilizer for Iowa corn production, but successful application takes more than an open field and available equipment.

If you feel behind this fall, you are not alone. Just under half of Iowa's corn is harvested, 4-inch soils are still in the upper 50s, and a very strong El Niño is likely to keep them warm well into November.

For fall anhydrous ammonia, the message is simple: it's not time yet. The recommendations haven't changed. What has changed is when the window is likely to open, and how much patience it will take to wait for it.

The Iowa State University (ISU) Crops Team has announced its 2026–2027 winter programming schedule and opened sponsorship opportunities for industry partners to support agronomic, conservation, and farm profitability education reaching thousands of stakeholders across Iowa and in other states. Sponsorships support programs that deliver research-based information to the agricultural community.

Significant engagement and proven impact from the 2025–2026 season include: 

There is a point every fall when manure management starts to feel less like agronomy and more like logistics, or, in a few years, panic. The crop is ready, or at least getting ready, to come out. The manure pit keeps getting fuller. The forecast has another chance of rain in it. You look across the field and wonder whether it is actually dry enough to get a tractor through without leaving tracks that will still be there next spring. And then you look at the pit again.

Iowa State University recommends that fall manure and anhydrous ammonia application not occur until the soil temperature at 4” is fifty and falling. What's changing this year is when that date is likely to arrive.