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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 ISRC will be hosting a Soybean Insights Webinar Series live via Microsoft Teams over the noon hour (CST) on the third Thursday in November through February. An opportunity for questions will follow each presentation. 

Wet weather has delayed harvest across much of Iowa, increasing the risk of grain sprouting and mold development before harvest. While sprouted grain is more common in small grains such as wheat, it can also occur in corn under the right environmental conditions, particularly when wet weather is combined with disease pressure.

Iowa has seen an extraordinary amount of rain over the last three months. Parts of central Iowa received 12 inches of rain in just two days in July, and September was one of the wettest on record, with some areas receiving more than 10 inches of precipitation and experiencing rainfall on more days than not. Beyond delaying harvests, all that water is showing up in perennial alfalfa fields as yellowing plants and bare spots, from flooding or prolonged periods of saturated soils. 

Harvest is underway across Iowa, and one of the biggest surprises this season may not be on the yield monitor. It is at the fuel pump. Diesel prices have increased sharply ahead of the 2026 harvest season, substantially increasing operating costs, making every tillage pass more expensive than budgeted for last winter. Harvest fuel costs are unavoidable; however, you may not need as much fall (or spring) tillage as you think to prepare for the 2027 growing season. 

Iowa rainfall in 2026 has arrived in “big buckets”, with above average temperatures and rainfall raising concerns about crop quality and post-harvest storage. Nearly three-quarters of Iowa’s weather stations reported at least 4 inches of rainfall or greater in September, according to ISU’s Mesonet data. As fields begin to dry out, several concerns have emerged about grain quality, both in-field and post-harvest.

Persistent rainfall across much of the Corn Belt have slowed both field operations and natural corn grain drydown this fall. As farmers evaluate harvest timing, the Iowa State University Corn Drydown Calculator can help estimate how quickly grain moisture will decline and support harvest scheduling decisions.

Farmers and landowners need a trusted advisor to help them site, fund and implement practices that protect water, soil and habitat resources. Did you know that Iowa has a conservation workforce of 70+ professionals, covering each corner of the state, who are ready to fill this need and help farmers at no cost? 

Soybean seed diseases are showing up across Iowa, which isn’t surprising considering the wet weather experienced in parts of the state over the past month (Fig 1). The rain is a double whammy for farmers this time of year as it favors continued fungal development and keeps combines from getting in the field. Some of the primary seed diseases showing up are purple seed stain and Diaporthe seed decay. 

The weather conditions over the past few weeks have certainly slowed the pace of harvest across Iowa. Conditions have also created several challenges that producers should be aware of before returning to the hustle and bustle of the fall harvest season.

Wet field conditions can create significant challenges during harvest. Temporary ponds, saturated low areas and wet spots that may look firm from the combine or tractor cab can quickly turn into places where heavy harvest equipment becomes stuck.

The following content is summarized from the What in the Weather Podcast by Dan Fillius, Justin Glisan, and Madelynn Wuestenberg. 

You can find more information about weather impacts on specialty crops and home horticulture on Dan Fillius' website and information from today's podcast on the latest newsletter. 

I have been sitting on the edge of my seat waiting to get into the field to harvest my silage research plots. In late August, I noticed so many fields being harvested for silage, but then the rain started. Now, driving across the state, there are half-harvested fields and fields that were set for silage still standing.

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: 

While corn silage and early grain harvest had begun in parts of Iowa, recent and persistent rainfall has brought fieldwork to a standstill across much of the state. In this regional crop update, ISU Extension field agronomists provide harvest progress reports and discuss emerging concerns, including corn standability, ear rots, and grain quality.

The recent rains have slowed or put a delay on harvest really getting underway across the state. When conditions allow, harvest will really ramp up. At the end of the day, the most important measure of a successful harvest is ensuring everyone returns home safely. National Farm Safety and Health Week, September 21-25, 2026, serves as an important reminder of why safety matters.  

A lot of people may be thinking about a late cutting this year, not because they planned one but because they never got their last traditional cutting off. The rain came, the fields stayed soft, and the window closed. Now there is standing forage that was supposed to be in storage weeks ago, and the question becomes whether to go after it late or write it off.

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.