By Kay Shipman
Farmers and conservationists have used dry dams for years to stop soil erosion. Now Southern Illinois University (SIU) researchers will learn the impact dry dams, also called water and sediment control basins or WASCOBs, have on water quality and nutrient management.
Menard County Farm Bureau member Brian Satorius hosted an Aug. 2 field day on his Petersburg farm -- the location for a study funded by the Nutrient Research and Education Council and supported by an Illinois Farm Bureau Nutrient Stewardship Grant to Menard County Farm Bureau.
“We had to change the way we farmed the field. We became frustrated because it was taking more time to work in the field. We wanted to slow down the nutrients and keep them in the field,” Satorius said, explaining why he installed his first WASCOBs.
Dry dams improve the farmability of sloping land, reduce erosion, trap sediment and reduce and manage runoff. They intercept and detain runoff in a basin where sediment settles. Runoff water is slowly released through an underground outlet that moves the water through a pipe to a stream.
Hal Pyle, Menard County district conservationist with the Natural Resources Conservation Service (NRCS), explained a grassed waterway wasn’t sufficient to control soil erosion on Satorius’ field with 8% to 10% slope. Now Satorius can farm around the WASCOBs “and not have grassed waterways to contend with,” Pyle said. “WASCOBs have been around; they’ve been in the (conservation) toolbox for years.”
Pyle noted WASCOBs are an eligible practice with the Environmental Quality Incentives Program (EQIP). Satorius said he used EQIP for this project.
In addition to mitigating the field’s soil erosion, Satorius also wants to see how WASCOBs and cover crops increase the organic matter of his average clay soil. The field will continue to be in a corn-soybean rotation.
A nutrient management perspective is being added to the project by a SIU research team of Professor Jon Schoonover and researchers Chris Blattel and Randy Lange. Schoonover, Blattel and Lange installed automated water samplers at each of four berms integral to two WASCOBs. Cover crops will be planted around one WASCOB, but not the other.
In addition, the SIU team will study another watershed that drains with an ephemeral channel, but no WASCOB. The goal is “to quantify how much water moves through,” Schoonover explained.
“We want to look at water in terms of nutrients. The sediment settles, and phosphorus would be bound to the soil,” he said.
Project equipment installation was completed in July so the researchers presented no data during Friday’s field day, but were able to demonstrate the project’s scope. Lauren Lurkins, IFB director of environmental policy, pointed out the location made it easier for Illinois Environmental Protection Agency Director John Kim and other regulators to view the effort.
While Satorius has worked with grassed waterways, this marks his first WASCOBs. “This (WASCOB) is not for everybody,” he added. “It has to work into your farm plan and for your field and typography. There are unanswered questions. I think it’s interesting to be part of those unanswered questions.”
“It’s great when our county Farm Bureau leaders are aware of these issues because of our efforts and step up to work with us and university researchers to forward the science,” Lurkins said. “This isn’t a one-and-one field day; it is a collaboration between farmer and research team that will continue years into the future. Ultimately, this will move forward the science of water quality in Illinois as we look to meet our goals of the Nutrient Loss Reduction Strategy.”