The harvesting of corn residue, referred to as stover, as ethanol fodder will focus on “flat soils with high yields in wet areas. That’s where to start,” according to Jim Hettenhaus, a chemical engineer who works on ethanol-related issues with the U.S. Department of Energy and private companies.
The selection of such fields addresses some of the economic and environmental concerns related to stover harvesting. Research into the impact of stover collection includes a trial run in Harlan, Iowa, where 50,000 acres of corn stover were harvested in 1997, followed by 100,000 acres in 1998.
“The logistics are humongous,” Hettenhaus concedes, but the studies provide operational guidelines that are needed, “Because, bottom line, stover collection has to be done in a sustainable way so it can be a win-win for both the soil and the processors.”
For example, plenty of residue remains on fields after stover collection. “We can adjust the cut on the stubble, generally cutting 4 to 6 inches above the crown, leaving anchored stubble as a wonderful windbreak,” he says. The corn leaves also are left on the field “because they provide surface cover to protect against water erosion coming from the the kinetic energy from raindrops.”
Soil moisture content demands attention, too. “We don’t want to go to areas where the stover is needed on the surface to hold in moisture,” Hettenhaus says. “But there are places where we can remove excess stover and believe it’s a win-win situation. We need to conduct…
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