The 2024 growing season will go down as one that produced good corn yields in many locations. Despite its fits and starts, if you avoided extremely late spring planting delays and summer flooding, yields should be on the high side. So far, prospects look favorable for high yield in the Corn Commentary field in central Indiana.

Two veteran agronomists from two large corn-growing states, Indiana and Illinois, share observations after reviewing USDA August estimates for state and national corn yields for 2024. Can these projected yields still be explained by following the longtime trend yield concept, or is something different happening? Here is a closer look.

Illinois corn yield

On Aug. 12, USDA projected average Illinois corn yield for 2024 at 225 bushels per acre. Emerson Nafzger, retired Extension crop specialist, expresses his thoughts in the Illinois Bulletin, published online by the University of Illinois on Aug. 19, in an article titled “Can Illinois corn yields really be that high?”

“I noticed some years ago that in each of the last three years that end with 4 — 1994, 2004 and 2014 — Illinois corn yields reached a new record high,” Nafziger says. “Each of these record yields exceeded the one from the decade before by about 22 bushels per acre.

Related:How to estimate your corn yields

“Early in 2024, in an exercise that I thought would illustrate the folly of making projections with such numbers, I graphed Illinois corn yields over the years from 1990 through 2023, and ran a separate line through annual yields and also through the three record-high ‘on the 4s’ yields, to project what yield might be in 2024. The August estimate for 2024 is actually 1.9 bushels higher than the yield projected for 2024 by my graphing.”

The normal trend line based on annual yield increases over the long term projects 206 bushels per acre for 2024 for Illinois. The Aug. 12 estimate is 19 bushels above trend line.

“We’ll have to wait to see if Illinois corn yield in 2024 actually reaches the August estimate,” Nafziger says. “If the final number is 225, then including 2024, the slope of the high-yield line I graphed, at 2.27 bushels per acre per year, would project a yield of 247 bushels per acre in 2034.

“It might seem foolish to project such a yield 10 years from now, but most of us would have thought the same thing about projecting the 2024 yield 10 years ago.”

Want to boggle your mind some more? Nafziger did some more figuring based on data, and determined that by 2056, average corn yield in Illinois could reach 297 bushels per acre.

Indiana corn yield

The projected corn yield based on the USDA August estimate for Indiana is a record 207 bushels per acre, up from 203 bushels per acre in 2023. Bob Nielsen, retired Purdue Extension corn specialist, looks at these projections a bit differently. He still sees them as strong yields, but believes they fall very near to expected ranges based on existing trend yields. When you create a trend line based on historical top yields, you are really looking at current ceilings to yield, and judging whether future yields can break through those ceilings, he explains.

“This gives us an idea of what the future record-high yields may be when growing conditions are extremely favorable,” Nielsen says. “However, it is clear that trend lines based on record-high yields do not accurately predict year-to-year grain yields because ‘extremely favorable growing conditions’ do not occur every year.

“That is one reason why I do not believe yield trend lines have shifted significantly and consistently. There have only been two major shifts in history — in the mid-1930s when hybrid corn came on board, and around 1956 when nitrogen fertilizer and other advancements occurred. Since then, the trend line has averaged just under 2 bushels per year rather consistently.”

The August USDA forecast for Indiana came in at about 11.6% above prediction using the historical trend line beginning with the 1956 yield data, Nielsen says.

“That’s pretty impressive, but it does not represent a record departure from trend line yield,” he says. “The greatest positive departures from trend yields in recent years are 1992 [14.9%], 2004 [12.4%] and 2014 [12.2%]. While not a record-high departure, the estimate for 2024 still represents good corn.”

Across the rows:
What others say about 2024 corn yields

Here are some reports figuring in from elsewhere across the Midwest:

In Michigan. Louis Wierenga, who farms just shy of 1,000 acres in the mid-Michigan town of Hastings, is cautiously optimistic about this year’s crop, noting how healthy his fields look. “But there’s a lot of season yet to go,” he says.

During four weeks from the end of June and the first part of July, his corn, soybeans, wheat and alfalfa received 10 inches of rain. Crops were wet and shot up quickly. Wierenga only got a portion of his 26% liquid fertilizer down on his corn. “We had to go very slow because we were bending corn,” he says. The rest he contracted with a high-cropper application.

No tar spot has been found on corn after aerial fungicide applications were applied July 18 and Aug. 7. — compiled by Jennifer Kiel, editor of Michigan Farmer

LOTS OF PROMISE: Louis Wierenga, Hastings, Mich., is cautiously optimistic about this year’s harvest. (Jennifer Kiel)

In Ohio. Even though crops got in late because of spring rain in parts of northwest Ohio, seventh-generation farmer Gary Wilson of Jenera says they are progressing nicely — unlike a good portion of southeast Ohio that is experiencing drought. Sporadic rains in the last couple of weeks have eased that situation, but yields will be impacted, he says.

Plain City grower Fred Yoder applied fungicides using drones on both corn and soybeans. “We’re considering using drones to plant a cover crop into corn about a couple weeks before harvest,” he says. “It’s one less drain on our time during harvest.”

Top of mind for Yoder, who did two postemergence herbicide applications on soybeans, is an outbreak of waterhemp on his farm, unlike any he’s seen before. “We put on a heavy rate of Liberty, and I think we just ticked them off,” he says. “But we’re hoping to stunt it enough so it doesn’t make it to seed.” — compiled by Jennifer Kiel, editor of Ohio Farmer

In Nebraska. Corn condition rated 3% very poor, 8% poor, 20% fair, 45% good and 24% excellent as of Aug. 16. Corn in the dough stage was 63%, near the 62% mark of last year and 61% for the five-year average. Corn in the dented stage was 26%, ahead of 16% last year and 12% average. 

Based on Aug. 1 conditions, Nebraska’s 2024 corn production is forecast at 1.88 billion bushels, up 9% from last year, according to USDA’s National Agricultural Statistics Service. This would be a record, if realized. Acreage harvested for grain is estimated at 9.7 million acres, up 2% from a year ago. Average yield is forecast at 194 bushels per acre, up 12 bushels from last year, and would tie the record high. — USDA NASS

In Iowa. Iowa’s corn production for 2024 is estimated to be 2.62 billion bushels, which is a 6% increase from the previous year. The yield is expected to be 203 bushels per acre, which is a 3-bushel increase from 2022. Estimates are that Iowa producers planted 13.4 million acres of corn for all purposes in 2024, which is the same as 2023 but 300,000 acres more than their March intentions. Of that, 12.9 million acres are expected to be harvested for grain. — USDA NASS