STORY AND
PHOTO BY DAN LEMKE
Harlan, Iowa — The John Deere combine’s deep
drone fills the damp fall air as it creeps forward,
gobbling up row after row of tall Iowa corn. But this
harvest is gleaning more than kernels.
The big green
machine has been modified to include a silage chopper.
The rear addition blows stalks, leaves, husks and cobs,
which normally end up on the ground, into a covered,
mechanized, unloading wagon. The corn stover is bound
for a nearby facility where it will be used for fibers
and research.
Tom
Schechinger, who operates Iron Horse Farms near Harlan,
Iowa, is monitoring the harvest. For almost 10 years, he
has conducted corn stover research projects for the U.S.
Department of Energy, National Renewable Energy Lab,
Iowa State University, Cargill/Dow and others.
Masses of bio
Mention “biomass” and many Midwesterners think “corn
residue,” with good reason. Corn stover is the most
abundant biomass available in the United States — about
220 million dry tons annually, or three tons of stover
per corn acre.
Schechinger
knows people are enthusiastic about corn stalks’
potential — from biomass energy to fibers to chemical
extractions. But he is realistic about the economics.
“Every time
you change the stover, it adds cost,” Schechinger says.
“Drying and pelleting for example, add to the cost. The
more you can use the stover as is, the better off you
are.”
Costly ventures
Cost often foils ventures that feature corn stalks.
While the raw material is abundant, it’s also bulky and
wet. And the northern Corn Belt’s harvest window is
relatively short. Storage issues, transportation and
drying costs can suddenly make this relatively
inexpensive and available biomass appear less
attractive.
"It depends
upon what it's competing against," Schechinger says.
Alan Doering,
AURI technical services specialist, hears regularly from
producers, grower groups and businesses interested in
using stover for building materials, hog mats, fuel
pellets, paper fiber and endless other uses.
“For any of
these projects to work, you have to look at the true
costs and methods of harvest and handling,” Doering
says. “Sometimes there are misconceptions that stover is
inexpensive, but once you factor in all the costs,
sometimes they are too high.”
But that’s
not to say there aren’t significant opportunities or
potential value in corn stover.
A barrel of stover
Schechinger says it’s time producers start
looking at stover like a barrel of crude oil.
Refiners don’t automatically convert the crude to
gasoline, rather the oil is processed into whatever will
bring the highest value, be it tar, grease or diesel
fuel.
Farmers
should look at stover the same way, he says. Separated
components, such as the silks, cob or fibers, or
fractions converted through biorefining or distillation,
may offer the best market.
“It all
depends on the end use,” Schechinger says. For example,
a company that makes horse bedding doesn’t want cob in
the stover because it can be irritating to step on. But
a chemical manufacturer that impregnates herbicides with
cob particles “will pay a good price if they can get
significant volume.”
As the axiom goes, Schechinger says, “One man’s trash is
another man’s treasure.”
