Thousands of acres of Delaware County crop land inundated over the weekend when the Lake Delhi dam burst may be difficult to harvest even if some crops survive.

Delaware County District Conservationist Keith Krause said the best estimate Monday was that 2,000 acres of crop land and 2,000 acres of pasture were covered by flooding along the Maquoketa River.

While some of the crops may recover, Krause said much of the pasture will basically be lost for this year because it will be too covered with silt and mud to grow forage.

“A lot of the mud and silt came out of Lake Delhi itself,” Krause said. “Some of the soybean fields will be a total loss.”

Just harvesting the surviving crops may pose a considerable hardship for farmers, Krause said, because of all the debris from Lake Delhi that made its way into fields.

“They’ve got trees, tin, wood from the docks, fuel barrels, and all kinds of debris swept down from Lake Delhi,” said Krause, of the U.S. Natural Resources Conservation Service.

The extent of soil erosion isn’t entirely clear, Krause said, because crop foliage makes it difficult to see the gulleys that have formed on the ground.

 While the Maquoketa River was falling in Delaware and Jones counties, the Wapsipinicon River in Jones County  hadn’t crested early Monday, July 26.

Rough preliminary estimates are that about 4,000 acres of cropland may have flooded in Jones County, according to Joe Wagner, district conservationist for the Natural Resource Conservation Service. He said it’s still extremely difficult to tell.

For either county, the amount of flooded crop land may exceed the impact of the 2008 floods, which affected the Iowa and Cedar rivers more heavily than the Maquoketa and Wapsipinicon.

Crops were much closer to maturity when they were flooded this year than in the June 2008 floods, according to Virgil Schmitt, extension field agronomist for Iowa State University.

Schmitt said it’s too late now for farmers to replant lost crops, whereas in 2008 farmers who lost crops could sometimes replant.

“We’re going to see more crop losses than we do in a normal flood year, particularly along the Maquoketa,” Schmitt said.

About one third of the corn acres planted in Mark Miller’s farming operations north of Maquoketa were covered by flood waters, or roughly 200 acres.

“Some that I can see is still standing,” Miller said. He nevertheless fears some heavy losses, however, and says crop insurance won’t make the loss whole because it averages the loss over his entire crop.

Miller said the recently-tassled corn is covered with mud and he’s not sure how it will respond to the flood because he’s never had crops flooded at this stage in their development.

“It’s quite a feeling to go to bed at night, hear those storms, and check the radar to see what’s coming down from the north,” Miller said.

Overall, Schmitt said the 2010 crops had been promising for farmers before the floods. Now, many of the farmers who planted in low-lying areas “are going to take it in the shorts.”

“We’re going to have some good crops and some zeros,” Schmitt said. “Hopefully, we’re going to have enough good crops to balance out the zeros.”

How fast the river levels fall will have a big effect on crop losses.

 ”If the crops are under water less than two days, they have a pretty good chance of surviving unless they are covered with mud or torn out by the roots,” Schmitt said.

A strong rain after floodwaters recede might actually help the crops, Schmitt said, by washing the mud off of leaves.

Crop consultant Skott Gent of Monmouth said that even when farmers have harvested crops from fields that were inunidated, their worries may not be over.

“One big unknown is that mold could form down in the ears (of corn) that were underwater,” Gent said. “The corn could still be unmarketable and unfeedable.”

Gent said many soybean plants that were underwater will probably be destroyed, because they are shorter plants and will be underwater longer.

“They’re still trying to flower and set pods,”  said Gent, Jackson County’s Farm Bureau president. “To do that through a heckuva thick layer of mud would be almost impossible.”

Gent said Delaware County farmers had just spent millions of dollars on conservation work to restore damage from the June 2008 floods.

 Miller said his crops were insured, but the help will be limited because the crop insurance program averages the yields over his entire crop instead of covering entirely the loss of just the fields that flooded.

Gent said farmers will be pretty much on their own paying for the additional erosion and sand deposition caused by the weekend floods.