SIOUX CENTER—Area farmers had a chance to check out construction of Sioux County’s first bioreactor as part of the Conservation Ag Fair held Tuesday, July 23.
A bioreactor is one of several practices that may be used to help prevent excessive nitrate contribution from tile drainage water leaving crop fields. Specifically, it is an edge-of-field structure that contains a carbon source, such as wood chips, through which water from field tile goes through to naturally remove nitrogen, or denitrify, the water before it goes to a waterway.
The 25-by-105-foot structure is being built west of the 360th Street and Harrison Avenue intersection, two miles north of Sioux Center on land owned by Dordt University that is within the West Branch of the Floyd River watershed.
The watershed was identified as a statewide priority area in the Nutrient Reduction Strategy six years ago due in large part to the fact that Sioux County boasts the highest concentration of livestock in the state.
Iowa’s Nutrient Reduction Strategy was prompted in an effort to reduce nutrient loads that are transported to the Gulf of Mexico. The plan establishes a 45 percent reduction of total nitrogen and phosphorus loads.
The goal for Sioux County watershed coordinator Colton Meyer, who organized the Ag Conservation Fair, is to encourage landowners within that watershed to adopt a variety of conservation practices such as terraces, cover crops, no-till, grassed waterways, filter strips, nutrient management and bioreactors to help the Nutrient Reduction Strategy.
Meyer identified the area along 360th Street as an ideal location for a bioreactor. After the city of Sioux Center and Dordt exchanged land to put the land under Dordt management about a year ago, the university greenlighted the bioreactor project idea. Along the waterway near the bioreactor, Dordt also is installing an approximately 60-foot saturated buffer strip — the second of its kind in the county, which is another practice used to help prevent excessive nitrate contribution from tile drainage water leaving crop fields.
Dordt worked with the Sioux County Soil & Water Conservation District and the Natural Resources Conservation Service based in Orange City to line up the projects.
“We’re excited to be able to do this,” said Gary De Vries, Dordt agriculture department chair and instructor. “It’s a prefect fit for the mission of our university and Ag Stewardship Center to be stewards of the land God has given us.”
De Vries said Dordt defines its Ag Stewardship Center as not just the new building on Highway 75 but also the full 260 acres surrounding the property.
“We want to be stewards with what God has given us and to be able to partner with the conservation center to implement such practices not only benefits the land but we can have classes study and what’s happening over time and share that research with Iowa State University Extension and other organizations,” De Vries said.
The bioreactor has the potential to filter the water draining off about 313 acres of land, most of which is owned by area farmers and not by Dordt.
“What’s exciting is that we can share what’s happening with those neighboring landowners and talk with them about possibly make adjustments in how they practice to help us tweak our studies,” De Vries said. “It’s a great community building project.”
Dordt sought cost-share funding for the project. Meyer said 75 of the cost is being covered by the federal Mississippi River Basin Healthy Watersheds Initiative; the other 25 percent is being paid for by the state’s Water Quality Initiative edge-of-field fund.
Studies of have shown 40 to 50 percent reduction in nitrogen levels of water coming out of bioreactors.
“It’s showing to be a highly effective tool in reducing nitrogen,” said Jamie Benning, water quality program manager with Iowa State University Extension and Outreach.
She noted that many of these practices are being constructed in Buena Vista and Pocahontas counties in Iowa.
“It’s important to have local projects,” Meyer said. “When farmers hear about something 10 counties away, they always think it’s applicable here. Now we can say, ‘Yes, it is.’ That’s why we’re really excited to work with Dordt and get a bioreactor and saturated buffer locally. In doing this, we’re able to showcase the practices and Dordt will do research so we’ll have some good data to show farmers.”