Making a Promising Treatment for Nitrate Pollution Even Better

Joe Sanford with the University of Wisconsin-Platteville has spent his academic career getting his hands dirty. The assistant professor of soil and crop science has been studying uses for biochar, a form of charcoal that’s made by burning wood and plant byproducts (such as pine chips or dried corn plants) under low oxygen conditions.

For his new project, funded by the University of Wisconsin Water Resources Institute, Sanford is building on findings in scientific literature and his own research in the field at the U.S. Dairy Forage Research Center at Prairie du Sac. He found that biochar, when amended to the soil, offered a 40% reduction in the amount of nitrogen in water runoff from corn silage bunkers used on farms for storage. (The silage is used to feed animals during winter.) Farmers typically treat silage bunker runoff by letting it flow through strips of vegetation that promote infiltration into the soil. These are called vegetative treatment areas (or VTAs). The biochar is added to the soil of these VTAs. Sanford is studying ways to make this 40% reduction even better.