MADISON -- Global yields of most biofuels crops, including corn, rapeseed and wheat, have been overestimated by 100 to 150 percent or more, suggesting many countries need to reset their expectations of agricultural biofuels to a more realistic level.
That's according to a study led by Matt Johnston and Tracey Holloway of the University of Wisconsin-Madison Nelson Institute for Environmental Studies and Jon Foley of University of Minnesota, which drew on actual agricultural data from nearly 240 countries to calculate the potential yields of 20 different biofuels worldwide.
The analysis, publishing today (Jan. 13) in the open-access journal Environmental Research Letters, indicates the biofuels production potential in both developing and developed countries has often been exaggerated. Why? Because current yield estimates, most of which are based on data from the United States and Europe, don╒t account for local differences in climate, soils, technology and other factors that influence agricultural outputs.
By offering an analysis of detailed, regional yield data that do encompass this variability, the scientists hope to empower wiser choices by countries about whether to invest in ethanol or biodiesel, which crops to plant, and how best to use existing farmlands. Although agricultural biofuels have been sharply criticized for their impacts on the environment and food supply, the reality is they╒re here to stay, say the researchers, at least until alternatives such as cellulosic ethanol are developed. And that makes the availability of sound information critical.
"The biofuels industry has grown at an incredible rate. It╒s a multibillion-dollar industry now," says Johnston, a graduate student in the Nelson Institute's Center for Sustainability and the Global Environment (SAGE). So, what we've tried to do is move beyond the back-of-the-envelope calculation -- the time for that is over. We need to look
|Contact: Matt Johnston|
University of Wisconsin-Madison