Congress mandates that gasoline contains 10 percent corn ethanol and the industry is pushing to boost this to 15 percent. The federal mandate contributes to higher grain prices as 40 percent of America's corn crop is poured into our gas tanks. Now the Washington Post is reporting a new study that finds that there is one other highly predictable consequence of the mandate: farmers are plowing up more land to grow corn thus reducing prairie grasslands inhabited and used by wild creatures. As the Post observes:

America’s prairies are shrinking. Spurred on by the rush for biofuels, farmers are digging up grasslands in the northern Plains to plant crops at the quickest pace since the 1930s. While that’s been a boon for farmers, the upheaval could create unexpected problems.

A new study by Christopher Wright and Michael Wimberly of South Dakota State University finds that U.S. farmers converted more than 1.3 million acres of grassland into corn and soybean fields between 2006 and 2011, driven by high crop prices and biofuel mandates (right). In states like Iowa and South Dakota, some 5 percent of pasture is turning into cropland each year.

It’s a big transformation in the heart of the country: The authors conclude that the rates of grassland loss are “comparable to deforestation rates in Brazil, Malaysia, and Indonesia.” And those changes are already having plenty of impacts.

As I pointed out last week in my column on President Obama's new energy initiatives outlined in his State of the Union speech:

Billions in federal subsidies have conjured the bioethanol industry into existence, but scientists still debate whether corn bioethanol actually reduces greenhouse gas emissions. A recent life-cycle analysis of corn ethanol production found that its greenhouse gas emissions could be "roughly 25 percent more than the entire lifecycle emissions of petrol."

Feds just please stop interfering in energy markets - no mandates, no subsidies, no nothing! You're doing more harm than good.

Go here [PDF] to read the new study in the Proceedings of the National Academy of Sciences.