This video, courtesy of the Iowa Soybean Association, shows the installation of a bioreactor on a farm field in Iowa. Bioreactors are structures that are used to help remove excess nitrogen from water that is flowing off of farm fields into waterways.
How do they work?
Subsurface bioreactors act as giant filters. Water travels down tile lines and is diverted into a bioreactor pit, which is filled with wood chips. The water...