Iowa Ag Secretary Bill Northey says as farmers see greater profits from planting corn, there is a debate about how much Iowa farmground should be used for growing corn to convert into ethanol. As the plant in Emmetsburg soon starts using not only the kernels of corn, but the corn stalks to produce ethanol, Northey says there’ll also be a discussion about how much of the stalk to harvest.

"That’ll be related to how much tillage we do on that ground, the slope of that ground, the type of that soil," Northey says. "We need to develop models that tell us that in this kind of condition we can take off maybe 60 percent of the corn stalks there and in a different kind of condition we can only take off 20 percent." Northey says Iowa State University researchers are already considering the question and commodity groups are pondering it as well.

Northey says the agency he now heads, the Iowa Department of Agriculture and Land Stewardship, is also part of that process and he may present a proposal to lawmakers to help finance such research. "Collectively, all of us together have to get those standards figured out," Northey says. Northey suggests farmers may implement a "variable harvest system" where more stalks would be left in parts of a field that have a greater slope.

"Part of this has to be to know that our harvest techniques are such that we are not causing problems with erosion in those fields," Northey says. That ethanol plant in Emmetsburg is currently being converted to using stalks — which the experts call "cellulose" — to make ethanol, but Northey says there won’t be a demand for corn stalks at other ethanol plants for a few more years. It leaves some time to figure out the proper techniques for harvesting those corn stalks.

"We’ll have several years to be able to really get the numbers down, but these are things that take several years to figure out so we do have to get about getting some of those experiments done this next year," Northey says. Earlier this week Northey said it might be necessary to develop a new piece of farm machinery to harvest just the corn stalks.