Harvest got underway unusually early in southwest Iowa this year, with some farmers beginning to run combines in early September despite planting later than normal. For Pat Sheldon, a farmer near Percival, Iowa, Sept. 11 marked a historic start to planting.
“This is the earliest we’ve ever started,” Sheldon says.
That jump-start to the harvest season came despite the farm planting nine days later than its federal crop insurance date.
“We started the 19th [of April], and our federal crop day is the 10th of April,” Sheldon says. “So we were surprised.”
The combination of accumulated growing degree units and a hot, sunny August helped push the crop toward maturity faster than expected.
“So the GDU is piled up and it was 110-day corn. And it got ready faster than anybody thought,” Sheldon says, as he sits in his shed on a rain delay. “So I’m glad we were ready.”
Early Harvest Reveals Wide Yield Variability
While the crop dried down quickly, yields across southwest Iowa have been far less consistent.
“There’s some really good corn, there’s some average corn, and then there’s really tough stuff,” farmer Luke Sheldon says. “Just pretty variable at this point for the farms we’ve been over.”
Pat Sheldon has already harvested a couple of his earlier corn fields, giving him an initial look at yield potential.
“We picked probably our two poorest farms and some early season stuff and we were pleasantly surprised,” he says. “For most of it, about 225 [bu. per acre].”
Those fields are on very sandy soils near the Missouri River, which can make them more vulnerable to weather extremes. In a typical year with more rainfall and less heat, those yields would be nearly 15 bu. per acre higher.
“In a normal year where we got a lot of rain, we’d probably have hit 240 out there, so we’re not too far off,” he says.
Still, Sheldon isn’t expecting 2026 corn yields to surpass last year’s crop.
“I doubt it. They might be as good, but I would doubt they would be better,” he says.
Heat and GDUs Speeds Maturity
Southwest Iowa experienced high heat through much of August, along with relatively few cloudy days.
Sheldon believes the combination helped accelerate crop maturity, but he also points to improvements in modern hybrids as a reason the crop was able to withstand the heat.
“I told my son, you know, 25, 30 years ago, we did just get under at the end of August with the heat,” Sheldon says. “The hybrids have so much more vigor now than they used to, and they’re just better built.”
The season wasn’t without challenges, however. Cool temperatures after planting slowed emergence, resulting in lower plant populations.
“So stand counts are just down from years past,” Sheldon says. “Not a tremendous amount, but, a couple thousand maybe, which makes a difference.”
The area also avoided some of the heavier summer rainfall seen elsewhere across Iowa this summer. Sheldon says timely rain around pollination helped maintain yield potential, particularly in fields that were planted later.
Rain Puts Harvest on Pause
The early harvest pace didn’t last uninterrupted. Recent rainfall moved into the area, keeping farmers out of the field for several days and forcing Sheldon to put the combine on hold.
“We’ve seen it about five days, five or six days in a row,” he says.
And now they’re seeing more rain from the remnants of Hurricane Polo. Sheldon says the rain is putting harvest on pause, and setting them back, but he’s not overly worried. Despite the wet conditions, disease pressure hasn’t been a major concern.
“No, the disease pressure’s been really light,” Sheldon says. “We’ve had scouts working all summer, and the whole area’s been real low disease this year. Both corn and soybeans. Corn and soybeans both.”
Later-planted Corn Could Surprise
Planting date may end up being one of the biggest variables in southwest Iowa cor yields this year. His later planted corn acres are what are producing the biggest yield estimates.
“Some of that corn that the estimates were high on was later planted, probably the first week or 10 days in May, so we’ll see how that turns out,” Sheldon says.
That later planting could ultimately prove beneficial by spreading out harvest maturity and helping farmers avoid taking too much corn out of the field at once.
“We kind of liked how it split things up, you know, planting it that way, as far as getting things out of the right moisture without getting it too dry,” Sheldon says. “So we’ll see what happens. We may do it again if it works out well.”
Soybean Yields Face Heat Test
While rainfall timing benefited corn around pollination, Sheldon believes August heat likely trimmed some soybean yield potential. When asked ow hot it was in August and if he thinks the soybeans took a hit, he says it definitely will have an impact. He just doesn’t know how much.
“Yeah, I think it took some of the gravy off the top of the yields,” Sheldon says. “I think we’re still going to have really good beans, but you can’t look at a field and tell until you get there at the combine.”
Soybean yields on the farm typically average in the upper 60-bushel-per-acre range, with the best years reaching about 70 bu. per acre. Sheldon believes 70 bu. per acre soybeans could still be possible in pockets this year, but he isn’t expecting that level across the entire farm.
“Probably not across the board,” he says. “We’ve got some sandy ground that’s bean ground and they won’t be that good.”
For now, harvest is providing the first real answers after a growing season marked by late planting, heat, uneven stands and highly variable field conditions. And while the first fields have offered some encouraging numbers, Sheldon says the rest of the crop will tell the bigger story as the combines move across southwest Iowa.
You can follow along and discover other yield updates across the Corn Belt with AgDay and U.S. Farm Report’s Harvest Your Independence Tour.
