This conservation-minded practice has a scientific sounding name, but it uses material as down to earth as corn cobs and wood chips to help keep excess nitrogen from reaching nearby streams. That in turn keeps it from reaching larger bodies of water.
One bioreactor that has been installed for some time and continues to work is on Mike Starkey's farm near Brownsburg. It was installed a few years ago during the Eagle Creek Watershed project to see if it could help reduce the amount of nitrogen leaving the farm.
Because Starkey no-tills and uses cover corps, he already reduces the amount of N that could either run off the surface or leave through tile lines, even without the bioreactor.
This area of the state was of particular interest because the stream running through this farm feeds into Eagle Creek Reservoir in northwest Marion County, It's a major source of drinking water for Indianapolis.
Jared Chew, Hendricks County district conservationist with the Natural Resources Conservation Service, explains that the bioreactor has worked, and continues to work. Once it was installed, a water monitoring station was installed next to it to measure the amount of nitrogen in water leaving the site, he explains.
Chew notes that the idea is simple. Before water can reach a stream, it spends time in an artificial basin filled with an organic material. Wood chips and corn cobs are two common choices. Liners are also used, and there are specific guidelines for constructing these bioreactors. The idea is for the nitrogen to become tied up in the organic material instead of leaving with water coming off the land, he says.
Other bioreactors have been installed in the Midwest, some for demonstration purposes, some as practices. A large one was installed by the Indiana Land Contractors Association at the Purdue University Throckmorton Research Farm near Romney a few years ago.
One was installed even before that by researchers at the University of Illinois on one of the farms used for the Farm Progress Show when it is held near Decatur, Ill.