Corey McKinney holds wood chips that will be used in a

Putting bioreactors into practice

March 4, 2021

A bioreactor is a shallow trench filled with woodchips located near a tile outlet to intercept and treat drainage water to remove nitrate. Bioreactors can be used in a variety of locations with no in-field drainage impacts to operations. 

Adding bioreactors is an easy practice for farmers and producers to get involved with.

Some of the typical site considerations in the planning process include:

  • Drainage outlet pipe size and depth
  • Drainage area
  • Suitable area near the outlet for a bioreactor
  • Nitrate concentration in the drainage water
  • Flow considerations

Once a farmer or landowner has decided to install a bioreactor, a site suitability survey is conducted, and the design stage begins. Once design is finalized, construction can begin. Construction proceeds by installing the control structure to intercept the drainage water, excavating the bioreactor pit, adding the wood chips and covering the pit with a soil cap.

“There are several considerations we put in to make sure we’re not hurting that current field drainage,” says Corey McKinney, former Iowa Soybean Association field services program manager. “Those farmers are still going to get the drainage they need, the bypass component of the bioreactor ensures that, and a variety of other considerations make sure we’re covering all the bases.”

Funding is available for farmers and landowners interested in installing a bioreactor on their farm. Cost-sharing options with organizations like the Iowa Department of Agriculture and Land Stewardship (IDALS) and Natural Resources Conservation Service (NRCS) may be an option for farmers interested in this practice. Those interested in learning more about bioreactors or seeing one in person can reach out to ISA Senior Research Scientist Chris Hay, PhD, here.

Check out this video about bioreactors and hear from Lee Tesdell, a farmer near Slater, who provides his experiences installing a bioreactor at the Tesdell Century Farm. Tesdell also provides data for the bioreactor’s performance over a period of five years.