An energy source from the rural South? Let’s hope it works out better than corn ethanol.
Researchers from the U.S. Department of Agriculture and Rowan Sage of the University of Toronto gathered samples of kudzu from different locations in the Southeastern United States at different times of the year to measure the carbohydrate content of the various parts on the plant including leaves, stems, vines and roots.
Based on estimates completed by these researchers, kudzu could produce 2.2-3.5 tons of carbohydrate per acre or about 270 gallons per acre of ethanol. Corn will produce approximately 210-310 gallons of ethanol per acre. Sage commented in the article that “kudzu will not completely solve anybody’s energy crisis. but it certainly would be a useful supplement.” The most important factor in using kudzu to make ethanol is the harvesting of the plants in a economical process. The roots which are large can cause a problem with harvesting, but you don’t want to destroy the plant by removing all the roots. To balance the harvesting expense, Sage said, “the kudzu plant requires zero planting, fertilizer or irrigation costs.
"There is a conundrum there," said Irwin Forseth of the University of Maryland in College Park. "Unless you’re going to let it come back and devote some land to cultivating it, it wouldn’t form a stable source. You wouldn’t want to put in a stable infrastructure and work out how to extract it from roots to have it go away after three years."
However, if existing corn ethanol manufacturing plants could be used to process kudzu, too, then the approach might be feasible, Forseth said.
Bob Tanner of Vanderbilt University in Nashville, Tenn., proposed using kudzu for energy in the energy crisis of the 1970s, but he now suggests that the starch, which is used as a gelling product in food in Japan, carries a higher value as a food product.
He advocates using the starch for food and converting the cellulose — the woody, fibrous carbohydrate that gives structure to the stems and leaves — into ethanol once processes under development are commercially available.
The fibers also make fine textiles, Tanner said. "My suggestion is, be creative. Don’t cuss at it. Use it creatively."