The New York Times reports:

America’s striking dietary shift in recent decades, toward far more chicken and cheese, has not only contributed to concerns about American health but has taken a major, undocumented toll on underground water supplies.

The effects are being felt in key agricultural regions nationwide as farmers have drained groundwater to grow animal feed.

In Arkansas for example, where cotton was once king, the land is now ruled by fields of soybeans to feed the chickens, a billion or so of them, that have come to dominate the region’s economy. And Idaho, long famous for potatoes, is now America’s largest producer of alfalfa to feed the cows that supply the state’s huge cheese factories.

Today alfalfa, a particularly water-intensive crop used largely for animal feed, covers 6 million acres of irrigated land, much of it in the driest parts of the American West.

These transformations are tied to the changing American diet. Since the early 1980s, America’s per-person cheese consumption has doubled, largely in the form of mozzarella-covered pizza pies. And last year, for the first time, the average American ate 100 pounds of chicken, twice the amount 40 years ago.

It’s not just Americans eating more American-made meat and cheese. Exports of poultry and dairy have risen more than tenfold since 1980, thanks to America’s farming efficiency, combined with government subsidies and rising demand from countries like China. Exports of animal feed itself have soared, too, industry data show.

Most of America’s irrigated farmland grows crops that don’t directly feed humans but instead are used to feed animals or to produce ethanol for fuel. And most of that irrigation water comes from aquifers. [Continue reading…]