By Rebekah Jones

BENTON CO. (IAWA) – Six Benton County landowners are installing underground filters to reduce nutrient runoff into Prairie Creek and the Cedar River through the county’s first “batch and build” conservation project. The collaboration brings together Iowa Soybean Association, Middle Cedar Watershed staff, and local contractors to make these edge-of-field practices easier for farmers.

The first batch includes eight bioreactors and three saturated buffers. These are edge-of-field practices that work quietly underground to reduce nutrient runoff into local waterways.

“Batch and build is a great way to scale edge-of-field practices,” said Evan Brehm, Conservation Agronomist with Iowa Soybean Association. Brehm helps recruit farmers for projects like this. “From a farmer perspective, they’re really attractive because they’re pretty much hands-off after they’re built.”

The saturated buffer or bioreactor connects to a farm’s already existing tile line. They use the natural biology of soil or woodchips to transform nitrate into nitrogen gas – preventing nitrate from reaching the waterway.

“Sometimes they’re not the most exciting thing to look at because you don’t know they’re there, but they are underground doing their work,” Brehm explained.

John Rathbun, Environmental Specialist in the Middle Cedar Watershed who leads the project, emphasized the downstream benefits. “This project benefits the Iowa Nutrient Reduction Strategy and the city of Cedar Rapids because the water that flows out of these bioreactors is cleaner water. It will go into Prairie Creek which flows into the Cedar River.”

The installation process is straightforward for participating farmers. Contractor Chase Broulik, who is installing the practices, noted that once a site is surveyed and deemed suitable, contractors handle the entire installation with minimal involvement from farmers.

“There’s a lot of things that make a site suitable,” Rathbun said. “The first thing we need is a landowner who is interested. Then we need tile drainage, preferably pattern tile. For saturated buffers we need a stream and we prefer the fields to slope down to that stream.”

This project complements the broader Cedar River Source Water Partnership initiative, which is a USDA project that brings millions of dollars to Eastern Iowa for conservation. Cedar Rapids leads the partnership and IAWA is a proud partner.

Are you a landowner in the Middle Cedar Watershed interested in conservation practices? Contact Evan Brehm with the Iowa Soybean Association to learn more about opportunities in your area. For a listing of Conservation Agronomists Statewide, visit IAWA’s Conservation Agronomists directory.