Even if all of the corn produced in the U.S. last year were, it would quench only 12 percent of the country's gas thirst, the report said. If the soybean crop were consumed as fuel, it would displace only 9 percent of the country's demand for diesel. Any appreciable upsurge in the use of those plants for fuel would also cut into the U.S. food supply.
The report, however, isn't dour about the potential use of biofuels. Instead, it advocates trying to develop high-cellulose, an approach that's been advocated by other scientists.
Switchgrass and similar plants have the potential to produce more energy than equivalent amounts of crops like corn that have been bred for food. Additionally, high-cellulose plants don't need fertilization and, because they are inedible, their use wouldn't affect food supplies.
These fuel plant crops also don't need much water and, conceivably, could be grown on land too dry for food crops. Like corn ethanol or soybean diesel, fuel made from these plants would result in lower tailpipe emissions than standard car gas. Synthetically produced fuels could also displace regular gas over time, the report stated.
Contrary to other recent studies, the report also found that both corn ethanol and soybean biodiesel supply more energy than is consumed in producing them. Corn ethanol delivers 25 percent more energy, while soybean diesel gives off 93 percent more energy than is required to harvest the crop and process the plants.
News of the report was first covered in the journal Nature.