Southeast Harvests First Sorghum Test Plot; Crop Expected to Become Future Biofuel

Photo of Dr. Wesley Mueller, left, and Dr. Michael Aide, right, standing in front of a plot of sorghum that grew 12-15 feet tall

Dr. Wesley Mueller, left, Southeast professor of agriculture, and Dr. Michael Aide, chair of the Southeast Department of Agriculture, stand in front of a plot of sorghum that grew 12 to 15 feet tall over the summer at the David M. Barton Agriculture Research Center. 

CAPE GIRARDEAU, Mo., Sept. 24, 2010 — The first test plot of sorghum harvested at Southeast Missouri State University’s David M. Barton Agriculture Research Center indicates it could be a viable renewable energy source and soon could replace corn as the preferred ethanol fuel crop.

Dr. Wesley Mueller, professor of agriculture at Southeast, said he and several students harvested 6.5 percent of the Center’s sorghum plot last weekend, generating 135 gallons of sorghum juice. Had they harvested the entire plot, it could have generated 2,100 gallons of sorghum juice, he said.

In the future, sorghum grown at Southeast’s Barton Center could produce 500 gallons of ethanol per acre if they maintain this year’s yield, he said.

These figures rapidly outpace corn, which generally yields just 235 gallons of ethanol per acre.

“So we’ve more than doubled the yield per acre, and we think we can do it with less water and fertilizer” than that used to produce corn, Mueller said. “I think we’re looking at the preferred crop for biofuels in the future just because of its efficiency and yield.

“The vision is that this will be the next big biofuel crop,” he said.

Mueller will discuss his research at David M. Barton Agriculture Research Center Field Day scheduled for 1 p.m. Sept. 27 at the Center located at 6885 State Highway 25, 1.5 miles south of Gordonville, Mo., along Highway 25.

Mueller said he and several students planted eight tenths of an acre of sorghum May 10, which grew 12 to 15 feet tall before it was harvested Sept. 18. He and a group of students harvested the crop by hand, using pruners and chain saws. 

Simplifying sorghum harvesting is a big obstacle to it replacing corn as an ethanol fuel crop, he said. A major machinery company is currently developing a prototype for sorghum harvesting and testing it in Tennessee and Arkansas. If it proves to be successful, “within five to 10 years, sorghum could replace much of the ethanol now being produced from corn,” Mueller said.

Sorghum can be converted to ethanol more efficiently than corn, he said, because ethanol is produced directly from sorghum’s sugar. On the other hand, starch in corn, must first be converted to sugar and then to alcohol, he said.

Mueller says the development of sorghum at the Barton Center is primarily for fuel alcohol, with the residue to be used for biochar  production. Alternatively, the sweet sorghum also could be converted into molasses. The research this season was funded by a $24,000 WIRED grant awarded to Southeast.

The sorghum harvested last weekend was taken to John Lorberg’s farm, west of Gordonville, Mo., where his roller press was used to squeeze juice from the stems. Mueller says the University has purchased a press of its own for this purpose, but it has not arrived yet. The juice harvested will eventually be used to run an ethanol-powered water pump at the Center as part of a demonstration, he said.

Once juice is squeezed from the stems, the remaining cellulose can be converted to charcoal by burning it with low oxygen.  The plants remove carbon dioxide (CO2) from the air and the charcoal (called biochar) can then be spread on fields where it could last hundreds of years in the soil, thus effectively removing carbon dioxide from the air permanently, Mueller said.

Sorghum also can be converted to molasses by boiling the water off. Although this is a lengthy process, Mueller says student organizations may try their hand at this venture in the future as a possible fund-raising activity.

Sorghum production could provide farmers in this region with many new opportunities, he said.

“It’s an alternative crop for farmers to rotate with the regular crops they normally plant,” he said.

Interest in sorghum production is growing, Mueller says.

“There is a lot of interest in this very work,” he said, adding Southeast is currently coordinating its efforts with Memphis Bioworks. The University of Missouri has also conducted research in this area, as well as Oklahoma State University, the University of Tennessee, the University of Kentucky and Louisiana State University.

Sorghum has the potential to be grown in all of the Plains states and even the deep South, Mueller said.

“Sorghum can be grown in a variety of places, which makes it attractive,” he said.

Mueller believes there is the potential for 200 small sorghum cooperatives to spring up in this region. Small ethanol plants are necessary, he said, because of the sorghum’s sheer mass which prohibits it from being shipped great distances due to cost constraints.

“I am very excited about it,” he said. “I think this has the potential to be the alternative fuel of the future.”

Southeast students insert stalksof sorghum into a press to harvest juice from the crop.