Mowed Down

A spike in corn and soybean prices has prompted farmers in the U.S. Western Corn Belt to convert more than a million acres of grasslands into croplands in just five years, researchers report in Proceedings of the National Academy of Sciences.

The Corn Belt covers Nebraska, Minnesota, Iowa, and North and South Dakota. Much of the prairie in this area is already gone, and birds that depend on grassland ecosystems for nesting are suffering.

The study authors wondered how recent increases in corn and soybean prices, driven partly by the biofuel market, had affected remaining grasslands. They studied data on land cover from 2006 to 2011 and found that the net amount of grassland converted to corn or soy croplands in the Corn Belt was more than 1.3 million acres. The rates of grassland loss seen across the region are “comparable to deforestation rates in Brazil, Malaysia, and Indonesia,” the team writes.

Corn and soy croplands in North Dakota, South Dakota, and Nebraska have crept to the west, an area that is more likely to experience drought, the authors say. But the potential for a high payoff from these crops seems to have justified the risk for farmers.

The study isn’t good news for waterfowl that breed in nearby wetlands. Ducks need grassland nearby to offer cover from predators. For example, most of South Dakota’s new corn and soy croplands are less than half a kilometer away from these breeding areas. Roberta Kwok | 19 February 2013

Source: Wright, C.K. and M.C. Wimberly. 2013. Recent land use change in the Western Corn Belt threatens grasslands and wetlands. Proceedings of the National Academy of Sciences doi: 10.1073/pnas.1215404110.

Image © Velychko |