Crop yields reveal impact of drought, derecho in parts of I states

A combine and grain carts make quick work of a Carroll County cornfield. As of Oct. 11, 45% of Illinois corn had been harvested with 68% of the crop rating good to excellent by the National Agricultural Statistics Service. (Photo by Catrina Rawson)

USDA adjusted its corn and soybean production estimates lower for the second time in a row earlier this month.

And many believe that trend could continue in the months ahead as the impact of various weather challenges, including drought and the Aug. 10 derecho, come to light throughout harvest.

USDA’s current crop production estimates stand at 14.72 billion bushels of corn, down from 15.3 billion bushels in August, and 4.27 billion bushels of soybeans, down from 4.42 billion bushels in its initial forecast of the season.

The national yield estimates slipped from 181.1 bushels per acre of corn and 53.3 bushels of beans in August to current projections of 178.4 and 51.9 bushels, respectively.

“The general perception of the market is yields for corn and soybeans will likely get adjusted lower the next couple of months,” Aaron Curtis, commodity risk consultant for MID-CO Commodities, said heading into this month’s report.

One of the areas contributing to the lower yield adjustments covers parts of the I states devastated by a combination of abnormal dryness/drought and the powerful Aug. 10 derecho that produced wind speeds in excess of 100 mph in parts of Iowa.

The number of acres farmers are unable to harvest in Iowa this season grew from an estimate of 550,000 in August to 850,000 acres this month.

Meanwhile, the statewide average corn yield estimates plunged from 202 bushels an acre in August to 186 bushels this month in Iowa and from 207 to 200 bushels in Illinois during the same stretch.

Soybean yield estimates in the two states also dropped, mostly as a result of drought and other issues.

“They were disappointing,” Lee County Farm Bureau president Don Meyer said, of soybean yields after finishing harvest of that crop on his farm in northwest Illinois this month. “We were probably headed for a great crop, but (weather challenges) probably knocked 10 to 20% off yields. We had no rain in August.”

A lack of rainfall during key crop growth periods in August also trimmed yield potential on the eastern side of Illinois.

“August led to a lot of variation in yield,” said Ron Haase, FarmWeek CropWatcher from Iroquois County. “Right now, our soybeans are running 10% below average.”

USDA pegged average soybean yields this month at 60 bushels per acre in Illinois (down 4 bushels from the August estimate), 56 bushels in Iowa (down 2 bushels) and 60 bushels in Indiana (down 1 bushel).

Illinois farmers remain on pace, though, to increase overall crop production this year compared to 2019 due to increased acres compared to last season’s historic prevented plantings. USDA currently estimates statewide production of 2.24 billion bushels of corn (up 21% from last year) and 615 million bushels of beans (up 16%) despite the recent downward adjustments in yields.