Excavation equipment is used to remove sand from a previously flooded field.
Rain is about the last thing Eddie Drewes wants to see arrive on his northwest Missouri farm this winter. Any excess moisture, whether from snow melt or rain showers, between now and planting season will only make his fragile fields more vulnerable to flood waters from the nearby Missouri River.
Still-broken levees in the area offer little to no protection for his land, three-fourths of which sat covered by water for 105 days last year.
Despite the risk of another flood, Drewes prepaid for his corn and soybean seed in December.
“We went in and dug out a lot of those fields and worked them last fall,” says Drewes, who farms near Craig in Holt County. “Some we also took a dozer to and tried to level up the places where the topsoil was gone.”
The Drewes family is not alone in its effort to reclaim farm ground after the devastating 2011 flood. Dozens of families farming land in the Missouri River Basin share their struggle.
“Most farmers are not really aggressively doing anything on the river bottom because the levees are still broke,” notes Wayne Flanary, Holt County Extension agronomist.
Flanary says the flood created four basic problems in area farmers’ fields:
- large sand deposits
- standing water
- scoured acreage where water washed away the topsoil
- at-risk ground inside the levees where the water can easily return this year and ruin crops.
Flanary says most of his farmer flood-related calls are about sand deposits. “‘What depth of sand can I mix into the soil?’ is the typical question I get.”
There is no simple answer, according to John Wilson, Extension educator for the University of Nebraska, based in Tekemah, Neb. Wilson was part of a team that developed a webinar, Farming after the Flood – Farmer Perspectives and Agency Resources. He and other agronomic specialists provided a variety of recommendations to farmers on reclaiming acreage impacted by the 2011 flood waters.
The Steps to Take
Wilson’s recommendations to farmers vary, based on the type of damage they experienced. For sand and sediment deposits that are less than 2” deep, he suggests that farmers incorporate them with typical tillage practices.
“Sand that is 2” to 8” deep should be incorporated with a chisel plow, moldboard plow or other more aggressive tillage equipment. Deeper levels of sand or sediment will need to be physically removed,” Wilson says.
Flanary adds: “Depending on what was below the new sand layer, it can be mixed if it is silt or clay. The addition of sand will lower the ability of the soil to hold water as it is mixed with other soil textures.”
To avoid this problem, Wilson says it is a good idea to fill the last 2’ to 3’ of a hole or eroded area with native topsoil from another area of the field.
Starter fertilizer will also play a valuable role in at-risk fields. Flanary says soil fertility tests are necessary to know what nutrient deficiencies exist.
“A lot of these soils can still produce good yields,” Flanary says. “We’ll probably see some phosphorus deficiency in them this year, and then they’ll hopefully be back to normal next year.”
Flooded soil syndrome creates a different set of management practices farmers need to implement, Wilson says. Corn is more susceptible to flooded soil syndrome than most other commonly grown crops.
To address this problem, Wilson recommends that farmers plant some crop other than corn. If corn is planted, he recommends banding nitrogen and phosphorus at planting. “This won’t necessarily offset all the potential yield loss associated with flooded soil syndrome,” he cautions.
For highly eroded fields, a cover crop may also provide protection for soils, as well as promote the repopulation of soil microorganisms, particularly arbuscular mycorrhizae. Such microorganisms aid the plants in nutrient uptake and lessen the effect of flooded soil syndrome.
Even if farmers didn't get a cover crop planted last fall, they can plant an early germinating cover crop such as oats this spring, Wilson advises.
In some cases, Wilson says farmers have ground that is so eroded that tillage alone won’t correct them. “It may need to be filled in with sediment and topdressed with native soil before it can be farmed again,” he says.
In severe cases, he adds, some fields will need to be abandoned because the expense of reclaiming them will outweigh benefits. Wilson says programs such as the Conservation Reserve Program (CRP) or the Wetland Reserve Program (WRP) will provide some financial support for the farmer, but probably won't offset the revenue lost from a productive piece of cropland.
For More Information
Visit http://flood.unl.edu/crops to see the archived versions of the webinars as well as fact sheets and other flood resources.