Recent flooding along the Mississippi and Ohio rivers left some western Kentucky crops in low lying fields underwater. As flooded tributaries in the north flow into the rivers, more may be at risk.

Depending on the length of the flood, some crops may be able to survive, but some may need to be replanted, said Chad Lee, University of Kentucky College of Agriculture Extension grain crops specialist.

"Plants can survive about 48 hours under water if the water temperature is above 70 degrees," he said.

It is not uncommon for river bottoms to flood along either the Mississippi or Ohio rivers. In fact, some farmers deal with flooding every year.

Soybeans normally are planted in these areas because their late planting date allows them to be planted after the rivers recede from spring rains. However, the exceptionally wet spring and rains in the Midwest have prolonged flooding, delayed planting and forced replanting.

"We have some corn and beans planted, but with the wet spring that we've had, some acres have not been planted yet," said Carla Harper, UK agriculture and natural resources Extension agent in Carlisle County.

Soybeans planted after June 10 risk lower yield potential. With that date past, that's a risk farmers wanting to replant have to take.

As flood waters from the north make their way south down the Mississippi River, the chance for flooding exists in Kentucky counties bordering the river. It was expected to crest at 44 feet on June 22 at Cairo, Ill. Flood stage is 40 feet.

If the river crests at 44 feet, it could be an issue for farmers in Ballard County, which is just across the river from Cairo. While soybeans are planted in river bottoms, some farmers planted corn behind the levy.

"At 44 feet, it would be over the levy here," said Tom Miller, Ballard County agriculture and natural resource Extension agent.

Flooding occurred along the Ohio River in Union County a couple of weeks ago when the river crested at 35 feet, said Rankin Powell, the county's agriculture and natural resources Extension agent.

When the water recedes, farmers should wait about five or six days before determining crop loss. To check for crop loss in soybeans, farmers need to inspect the main stem of the plant to see if it looks healthy.

"If it looks healthy, everything should be fine," Lee said. "If it does not look healthy, but there are leaves coming off it, there is still the chance it could develop additional branches and be okay."

Miller said even though the Mississippi was expected to crest on June 22, it could take the river until July 1 to recede. Typically the last date for planting soybeans is around July 4. Although it's a risky measure, Miller said he's known farmers who have successfully planted past that date.

"I know people who have gone to July 10 or July 20, but it's totally a crapshoot at that point," he said.

Lee said farmers on the fence about replanting should consider the size of the damaged field and if they have enough materials to replace the damaged crop. They should check the herbicide levels to make sure they can replant the field with soybeans.

Farmers should plant soybeans in narrow rows — no more than 15 inches apart — to bump up the population and get 160,000 plants per acre.

If the Ohio River stays below flood stage and crests at 29 feet, farmers along that river could begin to get back to work relatively soon.

Powell said if the weather stays clear this week, he expects double-crop farmers in Union County to begin harvesting wheat as early as the end of the week and begin planting soybeans shortly thereafter. The double-crop soybean harvest still is relatively on schedule as double-crop farmers normally begin planting soybeans around June 15.

"This means the first crop for some farmers will be planted as late as or later than double-crop beans," he said.