One of the great arguments against biofuels is the wisdom, if not the morality, of using land to produce fuel instead of food. But research out of Illinois suggests it doesn't have to be an either-or proposition.

Researchers at University of Illinois Urbana-Champaign have found that biofuel crops cultivated on land unsuitable for food crops could produce as much as half the world's current fuel consumption without adverse impact on food crops or pastureland.

The study, published in Environmental Science and Technology, identifies land around the world that is unsuitable for food production but could be used to raise biofuel feedstocks like switchgrass.

According to the researchers, many studies examining biofuel crop viability focus on yield – how productive the crop can be. They wanted to examine land availability to determine whether it is possible to produce sufficient biofuel to meet demand without sacrificing food production.

"The questions we're trying to address are, what kind of land could be used for biofuel crops? If we have land, where is it, and what is the current land cover," said a statement from Ximing Cai, a civil and environmental engineering professor who led the research.

In determining the availability and suitability of land, Cai and his team assessed factors like topography, soil properties and climate. They only considered so-called "marginal" land that has low inherent productivity, has been abandoned or is otherwise unsuitable for food production. They also assumed biofuel crops would be watered only by rainfall.

They considered several scenarios using fuzzy logic. In the first, they considered only idle land or land with marginal productivity. In the second, the also considered degraded or low-quality cropland. In that case, they estimated 702 million hectares [7.02 million square kilometers, 1.7 billion acres or 2.71 million square miles] of land available for biofuel crops like switchgrass or miscanthus. That's nearly the area of Australia, or more than twice the area of India.

From there they considered marginal grassland, where a variety of plants called low-impact high-diversity perennial grasses could be raised. Although such crops have lower yield than more common feedstocks like switchgrass, they have less environmental impact. Including such lands and crops nearly doubled the available land. That, they say, is enough to meet as much as 56 percent of the world's current liquid-fuel consumption.

Now that they've got the data, Cai and his team plans to look at how climate change could impact land use and availability.

"We hope this will provide a physical basis for future research," Cai said. "For example, agricultural economists could use the dataset to do some research with the impact of institutions, community acceptance and so on, or some impact on the market. We want to provide a start so others can use our research data."

Photo: Sugarcane production for ethanol in Brazil.

Sweeter Alternative/Flickr.

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