April 9, 2007

US scientists find more alternatives to replace corn for ethanol

While more and more US farmers are planting corn in hopes of getting better prices from ethanol production, many have ignored other alternate food sources, a panel of experts said. 

What many do not realize, is the potential for other crops, besides corn, to provide an alternate energy source to fossil fuels, scientists said.

Scientists studied corn, hybrid poplar, switchgrass, and other crops to determine the efficiency of various biocrops in terms of energy consumption and energy output.

The study,  was completed by Paul Adler (USDA), Stephen Del Grosso (USDA and Colorado State University), and William Parton (Colorado State University).

The scientists examined greenhouse gas fluxes and biomass yields for corn, soybean, alfalfa, hybrid poplar, reed canary grass and switchgrass.

The results of the study showed that when compared with gasoline and diesel, ethanol and biodisel from corn and soybean rotations reduced greenhouse gas emissions by almost 40 percent, reed canarygrass by 85 percent.

Greenhouse gas emissions were reduced by about 115 percent for switchgrass and hybrid poplar. Both switchgrass and hybrid poplar offset the largest amounts of fossil fuels reduced emissions compared to other biofuel crops and offset two twice as much fossil fuels if they are used for electricity generation via biomass gasification.

Study results showed that nitrogen emission resulting from production of the biofuel crops is the largest greenhouse gas source, while displaced fossil is the largest greenhouse gas sink followed by soil carbon sequestration.

This research shows that farmers will have a variety of biofuel crop options available in the future and that these biofuel crop rotations will have different environmental impacts.