Blog

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.

Harvest is a busy time of year, but it's also when farming is front and center. We'd love to hear from the farmers who know it best!

Are you a farmer? Have 10 minutes to share your thoughts? Five participants will be selected to win a $200 gift card.

https://www.surveymonkey.com/r/ISA_26

When questions arise regarding what to charge or pay for custom work done on Iowa farms, many look to the ISU Custom Rate Survey for guidance. However, the range in age of equipment, size, and custom services being provided across the state is vast. The survey encompasses a range of custom operators, from producers who provide a small amount of custom work as it fits their labor and machinery capacity to full-time custom operators who do nothing but custom work for others.

Palmer amaranth was first identified in Iowa in Harrison County in 2013, shortly afterwards isolated infestations were found in Fremont and Page Counties. In subsequent years I visited these sites and made casual assessments as to whether the population was increasing or decreasing and looked for evidence it was spreading outside of the initial areas. My last tour was in 2021, and I thought I had moved on to other things.

The Hodgson lab regularly scouts for field crop insect pests during the summer, which includes monitoring the distribution of new pests. Sometimes this effort is part of a regional grant, but occasionally it is for our own interest. This article shares the updated distribution maps for soybean gall midge and soybean tentiform leafminer in Iowa with detections from the 2026 growing season.

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.

It has been nearly 10 years since the first discovery of Asian copperleaf (Acalypha australis) in an Iowa crop field. Since that time, the species has been identified in crop fields in 12 Iowa counties and two other states. While we’re still developing management recommendations, now through crop harvest is an ideal time to discover it in crop fields.