THE future of biofuels just got brighter. Yields from farm-scale plantings of the switchgrass Panicum virgatum suggest that producing ethanol from the cellulose in these crops will be about twice as energy-efficient as previously estimated.
Researchers led by Ken Vogel of the US Agricultural Research Service in Lincoln, Nebraska, paid farmers in Nebraska, North Dakota and South Dakota to grow switchgrass for five years in plots ranging from 3 to 9 hectares. They measured the energy needed to grow the crops, including that used to make fertilisers and the diesel consumed by farmers’ vehicles.
From the biomass of grasses harvested,…
