Cellulosic bales dot countryside

Source: By Gene Lucht, Iowa Farmer Today • Posted: Friday, January 16, 2015

Cornstalk bales

IFT photo by Gene Lucht. A farmer bales cornstalks near Ames.

While the move toward cellulosic ethanol has often appeared to be in slow motion to outside observers, those working directly with the new industry say much is being learned about harvesting the cornstalks used to run the first cellulosic plants in Iowa and the Midwest.

“We’ve come a long way,” says Keith Webster, a researcher at Iowa State University.

Webster and his fellow researchers at ISU have been working with farmers and plant operators to address issues related to the harvest and storage of stover coming off of cornfields.

Andy Moser, a farmer and custom baler from Nevada, has worked with ISU and with the DuPont Pioneer cellulosic plant just outside of Nevada.

“Cornstalks are totally different” than hay when it comes to baling, he says. And, baling cornstalks for cellulosic ethanol production is also different than baling stalks for cattle bedding.

Moser had baled cornstalks in the past, but he says there was still much to learn when he began baling stalks for DuPont — about scheduling and logistics as well as baler settings and agronomic factors.

Some of those lessons were gleaned from the work of university researchers. Others came from experience in the field.

Webster says one thing researchers have learned is they need to find residue balance for soil health.

Balers do not just remove all the stalks from the field. Those stalks provide nutrients to the soil and cover to keep it from washing away.

Moser says the goal is to remove about half the stover from a field. The stover from a cornfield generally weighs about the same as the grain. So, if a field yields 180 bushels of corn per acre, that’s about four tons of grain. Moser bales about two tons of stalks from that acre.

While those figures are not precise, they do provide a basic rule of thumb.

Most farmers find such a move is a trade-off, he adds. They know they need to replace some of the nutrients lost by stover harvest.