Geneticist William Anderson is looking into how well bermudagrass, napiergrass and bahiagrass would work as biomass crops in Georgia and other Southeastern states.
At this point in his research, he gives bermudagrass top grades on its ability to convert to ethanol via fermentation. Yet it does require nitrogen and multiple harvests — and is “the backbone of grazing and hay production in the South. Some hay has been selling for $100 or more per ton,” says Anderson, who's based at the USDA-ARS Crop Genetics and Breeding Research Unit, Tifton, GA.
“It's probably not going to be the ideal dedicated energy crop,” he says. “The only reason I'm looking at it is to see if it has potential as an alternative market for growers. If there is an overproduction of hay, or if there are times pastures can't be used for hay, can bermudagrass be used as a biomass for conversion to bioenergy? It's certainly a possibility.”
Napiergrass, also known as elephantgrass, has more potential as a dedicated biomass crop, he says. This perennial is grown as forage in more tropical areas, such as Africa and South America. It grows to around the 10-12' range, much like miscanthus or sugar cane.
“It produces about the same amount of dry matter as those crops. But it hasn't taken on the same use for forage here as in other parts of the world, partly because of the management of it. You have to graze it when it's small and leafy for cattle to benefit.
“We're looking at the leaves and stems, trying to see if we can determine the genetic differences to exploit for breeding for bioenergy.”
Bahiagrass is a Southern perennial that doesn't yield as well as bermudagrass under good environmental conditions, but grows well on marginal land and is easily established. Anderson hasn't done much testing of this grass for use in bioenergy.