New research on the depletion of groundwater systems has raised concerns about the viability of irrigated farming in some of the country’s most productive agricultural regions. The study, which appears in the journal “Proceedings of the National Academy of Sciences,” shows severe groundwater depletion in intense agricultural areas like California’s Central Valley and the Midwest’s High Plains, according to ScienceDaily.

California's Central Valley is sometimes called the nation's "fruit and vegetable basket." The High Plains, which run from northwest Texas to southern Wyoming and South Dakota, are sometimes called the country's "grain basket." Combined, these two regions produced agricultural products worth $56 billion in 2007, accounting for much of the nation's food production. They also account for half of all groundwater depletion in the U.S., mainly as a result of irrigating crops.

The research basically shows that some irrigation systems are using groundwater at a faster rate than it can be replaced naturally. That could have long term consequences.

In Texas, some farmers are so worried about groundwater depletion that they’re battling state regulations that limit the amount of water they’re allowed to draw out of the Ogallala Acquifer. The Texas Tribune is following the story.

Water is a contentious issue across Texas, but tensions have been especially high in a 16-county groundwater conservation district stretching from south of Lubbock into the Panhandle, an area considered part of America’s “breadbasket.” There, farmers reliant on the slowly diminishing Ogallala are fighting to maintain their right to pump unrestricted amounts of water. The issue gained urgency last month when a landmark Texas Supreme Court opinion confirmed that landowners own the water beneath their property, in the same way they own the oil and gas.

All is not yet lost, however. Researchers say there are ways to make irrigation systems more sustainable. They urge farmers to:

Replace flood irrigation systems (used on about half of crops) with more efficient sprinkle and drip systems and expand the practice of groundwater banking -- storing excess surface water in times of plenty in the same natural aquifers that supply groundwater for irrigation.

For now, though, farmers across the country are anxiously watching the water system.