A project at Iowa State University is exploring the possibility of burning the leftover corn residue in farm fields to improve the soil. Soil science professor Randy Killorn says engineers use what he calls a reactor to “cook” the dried up stalks, husks and corn cobs left in fields after the fall harvest.

Killorn says in that process they extract bio-oil out of the stalks and end up with a product called “char.” The char is then used to make a substance called amoniumbicarbonate that’s put back into the soil. Killorn says the ammonium portion of the material serves as a fertilizer, and the rest helps put carbon back in the soil. He says they’re hoping to increase soil quality by returning the carbon to the soil that is lost over time.

Killorn says they believe a less high-tech process was used a long time ago to help improve soil. He says they’ve found evidence that people in the Amazon basin used to do something like this to get carbon back into the soil. Killorn says they need to determine if it can be a cost-effective way to improve the soil — and there’s one key to making that happen.

Killorn says they need to determine if they can make the reactor something that they can haul around to fields — otherwise he says it would cost to much to truck the corn stalks around. The U.S. Agriculture Department is kicking in nearly two million dollars to help pay for the project.