Dangerous pattern (Image: Georg Gerster/Panos)

Say goodbye to the grass. The scramble for biofuels is rapidly killing off unique grasslands and pastures in the central US.

Christopher Wright and Michael Wimberly of South Dakota State University in Brookings analysed satellite images of five states in the western corn belt. They found that 530,000 hectares of grassland disappeared under blankets of maize and soya beans between 2006 and 2011. The rate was fastest in South Dakota and Iowa, with as much as 5 per cent of pasture becoming cropland each year.

The trend is being driven by rising demand for the crops, partly through incentives to use them as fuels instead of food.


The switch from meadows to crops is causing a crash in populations of ground-nesting birds. One of the US’s most important breeding grounds for wildfowl, an area called the Prairie Pothole Region, is also at risk, with South Dakota’s crop fields now within 100 metres of the wetlands. “Half of North American ducks breed here,” says Wright.

Bill Henwood of the Temperate Grasslands Conservation Initiative in Vancouver, Canada, says the results are distressing. “Exchanging real environmental impacts for the dubious benefits of biofuels is counterproductive,” he says. “Last year’s record drought in the corn belt all but wiped out the crops anyway.”

Journal reference: PNAS, DOI: 10.1073/pnas.1215404110