Pam Marrone (right), founder and CEO of Marrone Bio Innovations, inspects some colonies of microbes. Marrone has spent most of her professional life prospecting for microbial pesticides and bringing them to market. Dan Charles/NPR hide caption

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Tanimura & Antle workers use tractors to install drip tape into fields that will be used to grow lettuce and other crops in California's Salinas Valley. Aarti Shahani/NPR hide caption

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Dalma Cartagena teaches a class on agricultural science to elementary-school students in Orocovis, Puerto Rico. "I'm preparing them to make good decisions when it comes to the environment and healthy foods," she says. Greg Allen/NPR hide caption

itoggle caption Greg Allen/NPR

Now that's a big root: Sweet potatoes aren't tubers, or thickened stems, like potatoes. Sweet potatoes are roots — swollen and packed with starch. U-ichiro Murakami/Flickr.com hide caption

itoggle caption U-ichiro Murakami/Flickr.com

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

An undated file photo provided by the Wisconsin Department of Natural Resources of a northern long-eared bat. A fungal disease has devastated the species, now listed as threatened. AP hide caption

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Dry, cracked earth is visible on a cantaloupe farm near Firebaugh, Calif., last August. Record-low snowpack levels in the Sierra Nevada mean most Central California farmers will face another year without water from the federal Central Valley Project. Justin Sullivan/Getty Images hide caption

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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

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A field of unharvested wheat is seen in Ashby-de-la-Zouch, England, in 2012. Wheat wasn't cultivated in Britain until some 6,000 years ago, but DNA evidence suggests early Britons were eating the grain at least 8,000 years ago. Darren Staples/Reuters/Landov hide caption

itoggle caption Darren Staples/Reuters/Landov

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

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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
Samuel LaHoz/Intelligence Squared U.S.

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

Allen Peterson's farm, near the city of Turlock, Calif., lies next to a concrete-lined canal full of water. He's one of the lucky ones. Dan Charles/NPR hide caption

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