CHICAGO Tracking the amount of U.S. corn and soybeans lost to the worst flooding in 15 years for the Midwest, one of the world's key food production areas, will be a daunting task, crop specialists said on Friday.
"The key word is uncertainty. We're getting close to the end of time to replant crops, but that leaves a lot of unknowns," said Bob Nielsen, extension agronomist with Purdue University in Lafayette, Indiana.
"How severe is the crop damage in those areas that survived? How stunted are they going to be? What's the true effect going to be on yield? That depends on the rest of the summer," he said. "It's a very confusing mess."
Iowa, last year's top grower of corn and soybeans, was the hardest hit as many rivers swelled beyond their banks. Governor Chet Culver declared 83 of Iowa's 99 counties disaster areas.
The Cedar River at Cedar Rapids, site of several big grain processing plants drawing from nearby fields, rose to record levels over the weekend. In the state capital of Des Moines, which is surrounded by corn and soy fields, a levee holding back rising flood waters broke and swamped the city.
Eastward, more than two dozen levees holding back the swollen Mississippi from agricultural land have overtopped, sending floodwaters into thousands of acres in Iowa, Illinois and Missouri this week.
"It's impossible to come up with a number. The flooding is going to have a huge economic impact. There are river bottoms in Iowa that won't be planted this year. There's so much moisture sitting there. It depends on how fast the water can get away," Palle Pedersen, extension agronomist at Iowa State University at Ames, said.
Iowa Farm Bureau President Craig Lang cited estimates of the state's corn and soybean losses at $3 billion.
Iowa's weekly state crop report on Monday gave the best lead so far -- reporting that 9 percent of Iowa's corn acres were flooded and 8 percent of the soybean crop was flooded.
That equates to 1.19 million corn acres and 784,000 soybean acres based on USDA's March planting intentions report.
Using Iowa's average yield of 170 bu/acre over the last three seasons, that amounts to a potential loss of 202 million bushels of corn. Using the 3-year average yield for soybeans of 51.5 bushels per acre, the potential loss is 40 million bu.
Some of those acres will be replanted. But it is too late in the season to plant corn confidently in Iowa, and nearly too late to plant beans, with any prospect of half-decent yields.
Don Rust, a farmer from Ursa, Illinois, estimated cropland 13 miles long and six miles wide was flooded in his area on the eastern side of the river across from Iowa.
"It will take three to four months for this water to recede," Rust said, looking over flooded fields. "This is a lot of good land that will be useless until next year."
Grain analysts hope that USDA's June 30 planted acreage report will give clues to the damage. But those farmer surveys were conducted during the first two weeks of June before much of the flooding and levee breaks this week.
Analytical firm Informa Economics issued its latest U.S. corn and soybean planting estimates to clients on Friday.
Traders said those estimates were based on surveys made in late May and early June -- before the extensive flooding.
They said Informa put U.S. corn acres at 87.4 million acres, up 1.4 million from USDA's current estimate, and soybeans at 73.3 million, down 1.5 million from USDA.
But they also said Informa already made adjustments on its estimates, down 900,000 planted corn acres and harvested corn acreage by 2.6 million. Soybean acreage was seen up 1.2 million from its forecast released on Friday.
(Additional reporting by Karl Plume, Lisa Shumaker, Julie Ingwersen and Nick Carey in Chicago. Writing by Christine Stebbins, Editing by Peter Bohan and Christian Wiessner)