The concept isn't new but it still isn't mainstream, so Purdue University ag engineers and other researchers want to get a closer look at just how well a bioreactor can help tie up nitrogen left in the soil after harvest and prevent it from reaching streams through tile lines.
Bioreactor is a fancy name for a relatively large area that's hallowed out, lined with a plastic liner, and filled with wood chips or another natural source. Researchers from the University of Illinois have already tried similar projects, with one located near the Farm progress Show grounds in Decatur, Ill.
The idea is that water from tile flows into the reactor basin before making it into main tile that allow water to exit off the site. While at the bioreactor site, some of the nitrogen should become tied up with the natural material, meaning less nitrogen becomes runoff.
Purdue researchers plan to study the system, which was just installed at the Purdue Throckmorton Research Venter south of Lafayette, or north of Romney. The bioreactor is in an area near a small ditch. It was installed fairly quickly because several members of the Indiana Land Improvement Contractors Association came aboard to do the installation work. In return there was a field day with presentations offered for anyone who wanted to see how the installation was done.
While you likely won't be installing a bioreactor yet this fall, it could be one way to capture excess nitrogen every year in the future, not just after a drought year. The potential for larger than normal amounts of N in the water once the subsoil becomes saturated later in the year or in the winter is because in most areas, the crops didn't use all the N applied. Meanwhile, some farmers are doing what they can to try to salvage part of that N by establishing cover crops. The crop's roots will hopefully latch on to N that hasn't yet leached too deep into the soil profile.