Growing switchgrass as a biofuel crop may provide more potential energy per acre than previous estimated. According to field trials conducted by energy crop company Ceres switchgrass can produce up to 10 tons of biomass per acre, as compared to the federal government’s projected yields of two to four tons.

More recently, a report, “90-Billion Gallon Biofuel Deployment Study,” co-authored by Sandia National Laboratories found that six tons of biomass was harvested per acre of switchgrass.

A large Nebraska farm study revealed that switchgrass produces 540-percent more energy that consumed during its growth, harvest and processing into cellulosic ethanol, compared with soybean-based biodiesel which offers a 320% energy return. The highest yield reported be Ceres was an experimental variety in California, at 19 tons per acre.

Last year, Ceres supported the prediction that 30% of U.S. transportation fuel could be replaced by dedicated energy crops. However, recent studies have found bioelectricity to be more efficient, offering more energy per acre of cropland, and presenting even fewer environmental impacts.

Ceres’ subsidiary Blade Energy Crops, which consistently provided the highest average yields across several locations during the field tests, released a crop management guide specifically for producers interested in switchgrass last year. Competing with switchgrass is miscanthus, which can convert sunlight into biomass more efficiently.

Switchgrass grows below the surface before it can provide the biomass necessary for ethanol production, making it difficult for farmers who don’t have the necessary capital for a two to three year return. The study by General Motors and Sandia National Laboratories found that 21 billion gallons of ethanol could be produced per year by 2022 without displacing current crops, and could even rise by 2030 to a sustainable 90 billion gallons.

Switchgrass is also part of the growing bioplastics industry, as once plastics have been combined with a polymer found in switchgrass, they can ‘grow’ plastic before the biomass is harvested for energy. An era ago American farms began to use machine power, freeing up millions of acres previously-required to grow crops to feed livestock. Now we are reversing the cycle, dedicating acreage to grow crops to feed our mechanical beasts of burden.