In particular, second-generation lignocellulosic biofuels from agricultural wastes and non-food crops such as switchgrass promise sustainability and avoid diverting food crops to fuel.
But he says biological approaches could work better with feedstocks such as switchgrass.
The ability to grow energy crops, such as switchgrass, on marginal lands means that they wouldn't have to compete for the best farmland.
But cellulosic sources of ethanol, such as switchgrass and wood, can be grown on marginal lands, greatly increasing potential fuel production.
Biofuels from nonirrigated sources, such as switchgrass, use relatively little water, but ethanol made from irrigated corn is hugely water-intensive.
Alcohol fuel: Celunol, based in Cambridge, MA, tests its cellulosic-ethanol process in this pilot-scale plant, which converts biomass such as switchgrass into ethanol.
What's more, fermenting bacteria and yeast could make ethanol from agricultural waste and weeds such as switchgrass that could be grown on land unsuitable for food crops.
Other herbaceous crops such as switchgrass performed well in certain locations and may offer flexibility in cropping choice.
With genetic mapping, for example, researchers have been working to identify genes that can be controlled to increase biomass production in perennial species such as switchgrass (Panicum virgatum), an important source of biofuel.
Biofuels Watch, a British lobby group, worries that a craze for the stuff could see virgin land tilled specifically to grow crops such as switchgrass, whose only purpose was to be pyrolised and buried.
