A cereal rye cover crop grows (at left) in a field where corn was recently harvested. Cover crops can capture nutrients such as nitrate and prevent them from polluting nearby streams. Courtesy of Paul Jasa/University of Nebraska-Lincoln hide caption

itoggle caption Courtesy of Paul Jasa/University of Nebraska-Lincoln

The city of Des Moines, Iowa, sits on the Raccoon and Des Moines rivers. The city's water works says it will sue three neighboring counties for high nitrate levels in these waterways. iStockphoto hide caption

itoggle caption iStockphoto

Sister Elizabeth feeds Yoda, a water buffalo calf at the ranch. The nuns bought the buffalo to make mozzarella. Sonja Salzburg for Harvest Public Media hide caption

itoggle caption Sonja Salzburg for Harvest Public Media

Owner Mary Kraft at Badger Creek Dairy outside Fort Morgan, Colo. Luke Runyon/KUNC/Harvest Public Media hide caption

itoggle caption Luke Runyon/KUNC/Harvest Public Media

Pinatas are among the new generation of club apples — varieties that are not just patented, but also trademarked and controlled in such a way that only a select "club" of farmers can sell them. Stemilt Growers LLC hide caption

itoggle caption Stemilt Growers LLC

Workers sort through key limes at a packaging house in Apatzingan, Michoacan. More than 90 percent of limes imported into the U.S. come from Mexico. Carrie Kahn/NPR hide caption

itoggle caption Carrie Kahn/NPR

Backers of the new Open Source Seed Initiative will pass out 29 new varieties of 14 different crops, including broccoli, carrots and kale, on Thursday. J. Scott Applewhite/AP hide caption

itoggle caption J. Scott Applewhite/AP

Dairy cows feed through a fence at an Idaho farm, in this 2009 file photo. Idaho's Gov. C.L. "Butch" Otter enacted a bill Friday that criminalizes the act of secretly filming animal abuse at farms. Charlie Litchfield/AP hide caption

itoggle caption Charlie Litchfield/AP

Benny Bunting, a farm advocate for Rural Advancement Foundation International-USA, in front of one of his old chicken houses in Oak City, N.C. Dan Charles/NPR hide caption

itoggle caption Dan Charles/NPR