Tyson Foods says it has already reduced its use of human-use antibiotics by 80 percent over the past four years. Here, Tyson frozen chicken on display at Piazza's market in Palo Alto, Calif., in 2010. Paul Sakuma/AP hide caption

itoggle caption Paul Sakuma/AP

Chickens stand in their cages at a farm near Stuart, Iowa, in 2009. This week, bird flu hit a large poultry facility in Iowa. It's not clear how the virus is evading the industry's biosecurity efforts. Charlie Neibergall/AP hide caption

itoggle caption Charlie Neibergall/AP

Workers pick asparagus in early April at Del Bosque Farms in Firebaugh, Calif. This year, some farmers in the state will get water, others won't, based on when their land was first irrigated. David Paul Morris/Bloomberg/Getty Images hide caption

itoggle caption David Paul Morris/Bloomberg/Getty Images
Leif Parsons for NPR

These beans, grown on test plots at the International Center for Tropical Agriculture in Colombia, can thrive in temperatures that cripple most conventional beans. Courtesy of CIAT/Neil Palmer hide caption

itoggle caption Courtesy of CIAT/Neil Palmer

Central Illinois corn farmer Jerry McCulley refills his sprayer with the weedkiller glyphosate on a farm near Auburn, Ill. A new assessment of the chemical finds that the (uncertain) risks mainly affect the people who work with it or who come in direct contact with areas where it's applied. Seth Perlman/AP hide caption

itoggle caption Seth Perlman/AP

An economist with the Rand Corporation argues that Los Angeles' fast-food ban failed because it merely blocked new construction or expansion of "stand-alone fast-food" restaurants in neighborhoods where that style of restaurant was uncommon to begin with. David McNew/Getty Images hide caption

itoggle caption David McNew/Getty Images

Mas Masumoto grew up on his family farm southeast of Fresno, Calif. His 1987 essay "Epitaph for A Peach," in which he bemoaned the loss of heirloom flavors, captured his changing philosophy as a farmer. It also helped turn his farm into a landmark in the local-food movement. Dan Charles/NPR hide caption

itoggle caption Dan Charles/NPR

Nahun Villagomez Sanchez washes freshly dug Red LaSoda potatoes at T&D Willey Farms near Madera, Calif. Dan Charles/NPR hide caption

itoggle caption Dan Charles/NPR

Arctic Granny (right), a GMO variety created by Okanagan Specialty Fruits, got the gren light from federal regulators Friday. The apple doesn't turn brown like a conventional Granny Smith apple (left). Okanagan Specialty Fruits hide caption

itoggle caption Okanagan Specialty Fruits

Albion strawberries, a variety created at UC Davis, grow on the Chino family farm in Rancho Santa Fe, Calif., on March 7, 2013. Mike Blake/Reuters/Corbis hide caption

itoggle caption Mike Blake/Reuters/Corbis