Husks, dust, and the rumbling of a large green combine filled the air as Jim Hogan worked in his cornfields near Mount Vernon.

Through the back window of the cab, one could see a growing mass of newly harvested kernels. The corn could be processed for use in food, but this batch will be used to produce grain ethanol at the Big River plant in Dyersville.

The United States dominates the ethanol-fuel industry, producing 50 percent of the world’s supply, according to the Renewable Fuels Association. Ethanol production brings economic opportunities to the biggest U.S. producer, Iowa, where 24 percent of U.S. ethanol is created.

“If you look at a map of the nation’s ethanol plants, it is like a bull’s-eye, and the eye is right over Iowa,” said Brian Crowe, the program manager for the Iowa Power Fund in the state Office of Energy Independence.

However, production trends could shift as ethanol moves toward cellulosic ethanol made from plants such as switchgrass, algae, and corn stover — the stalks, leaves, and cobs that remain on the ground as Hogan’s combine chugged away with its load of kernels.

Researchers at the UI Center for Biocatalysis and Bioprocessing and Iowa State University are currently examining how to make cellulosic ethanol from the more abundant, non-food resources.

“[UI researchers] are looking at how to take a corn cob and crack it into several different gases,” Crowe said.

The United States does not grow enough corn to meet its energy needs, said Robert Brown, a professor at the Iowa State University and the director of the Center for Sustainable Environmental Technologies.

“Right now, [corn stover] is a lost opportunity as an energy source and a lost revenue for farmers,” he said.

POET Project Liberty, a program supported by the Iowa Power Fund, will add cellulose-to-ethanol capabilities to the current biorefinery in Emmetsburg, Iowa.

The cellulose portion of the plant should open around late 2011 as one of the first plants to produce cellulosic ethanol on a commercial scale, Crowe said.

However, switching to cellulosic ethanol would present a few challenges to Iowan farmers.

“If plants switch to [cellulose], they will have to pay more,” Hogan said. “Because we would need to pay to lay down fertilizer since the corn stalks would not be there to put nutrients back into the soil.”

Hogan said he would definitely be interested in harvesting the corn stover, but only if prices are sufficient to cover nutrient replacement.

Crowe said the cellulosic industry would require a group of early adopters who were willing to invest in machines that could harvest both kernels and stover at the same time.

Officials also need to work on creating methods for transportation and storage.

“There is no real infrastructure,” Crowe said. “It is kind of like inventing the wheel.”

Plants such as POET open up new markets for farmers and, because it’s tied to supply sources, ethanol production cannot be sent overseas. However, plants also tie up important resources.

According to research at the University of Illinois Urbana-Champaign, ethanol production requires approximately three gallons of water for every gallon of fuel. While some worry this demand could stretch the water supply, Crowe said they’re working to find more efficient methods.

“We are creating a value-added commodity,” he said. “There will have to be some Iowa resources that goes into that.”