Research shows converting land for biofuel crops increases carbon debt

September 26, 2011 | Research, UToday
By Feliza Casano

Converting grasslands to soybean and corn crops to create biofuels would release a significant amount of carbon into the atmosphere, limiting the positive environmental impact of the cleaner energy source, according to research conducted by Dr. Jiquan Chen, UT professor of environmental sciences.

Chen and Dr. Terenzio Zenone, UT postdoctoral research associate, investigated the conversion of grasslands in the Conservation Reserve Program into farmland used to produce bioenergy crops and discovered the carbon debt increase in doing so would be too high.

Carbon debt is the carbon dioxide and other greenhouse gases released into the atmosphere during the process of converting the land for agriculture use. According to Chen, the carbon released in the process would take decades to pay back with the biofuels that would be created from the crops.

“There is a long list of challenges associated with bioenergy: how and where to convert biomass into ethanol, how and where to produce the biomass. From this question comes our topic of research,” Chen said. “This paper specifically addresses the issue of converting conservation land, which is mostly prairie land similar to native grasslands, which provide good habitats for plants and animals.”

The research, “Carbon Debt of Conservation Reserve Program Grasslands Converted to Bioenergy Production,” was published in the Proceedings of the National Academy of the Sciences, one of the most widely read and cited scientific publications in the world.

There are more than 30 million acres of land in the country that are part of the Conservation Reserve Program, which encourages farmers to grow natural vegetation rather than crops.

“This research is important because this paper, along with others published in different scientific journals, focuses on the ethics of land-use change on carbon balance, which is a main environmental issue right now,” Zenone said. “This is the first case where ethics of land-use change have been measured in this way. No other paper does this.”

“The landscape in northwest Ohio is dominated by privately owned farmland, primarily managed corn or corn and soybean systems,” Chen said. “Our research will have a direct impact on farmers to decide whether they want to make these changes, because the carbon debt could take more than 120 years to balance out.”

The research was conducted in partnership between UT and Michigan State University. Both are participating in the Great Lakes Bioenergy Research Center’s research consortium sponsored by the U.S. Department of Energy.