A line of fire turns brown grass into black earth. Dan Charles/NPR hide caption

itoggle caption Dan Charles/NPR

Wal-Mart is promising to drive down the prices of organic food by bringing in a new company, WildOats, to deliver a whole range of additional products. Wal-Mart/Flickr hide caption

itoggle caption Wal-Mart/Flickr

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

Live tilapia raised by Blue Ridge Aquaculture are loaded into a truck bound for New York. Dan Charles/NPR hide caption

itoggle caption Dan Charles/NPR

Farmers participate in a CGIAR climate training workshop on how to interpret seasonal rainfall forecasts in Kaffrine, Senegal. Courtesy of J. Hansen/CGIAR Climate hide caption

itoggle caption Courtesy of J. Hansen/CGIAR Climate

Customers order food from a McDonald's restaurant in Des Plaines, Ill. The company has promised to start buying "verified sustainable beef" in 2016. Scott Olson/Getty Images hide caption

itoggle caption Scott Olson/Getty Images

From the botanical to the economic, spring's iconic vegetable still harbors surprises. Sharon Mollerus/Flickr hide caption

itoggle caption Sharon Mollerus/Flickr

The world is increasingly relying on a few dozen megacrops, like wheat and potatoes, for survival. Above, a wheat field in Arkansas. Danny Johnston/AP hide caption

itoggle caption Danny Johnston/AP

Empty shelves where eggs should be at a Whole Foods Market in Washington, D.C. The store blames increased demand for organic eggs. Dan Charles/NPR hide caption

itoggle caption Dan Charles/NPR

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

Chickens gather around a feeder in a Tyson Foods poultry house in Washington County, Ark. April L. Brown/AP hide caption

itoggle caption April L. Brown/AP

Allen Williams grows corn and soybeans for Clarkson Grain, which has been selling GMO-free grain to Japan for years. Dan Charles/NPR hide caption

itoggle caption Dan Charles/NPR