Twenty-nine years ago photographer Chris Johns set off for his first international assignment. It wasn’t a glamorous one—the topic was soybeans—but he was determined to make it memorable.

“When you are doing a story on soybeans, you are looking for any surprising and interesting things you can find—that’s sort of the fun of a story like this,” says Johns, now executive director of the National Geographic Society Centers of Excellence.

A freelancer at the time, Johns had submitted 17 story ideas to then director of photography Bob Gilka, and all but one had been rejected, so he was excited to finally catch a break.

“[Gilka] asked if I’d be interested in a story about soybeans, and I said, ‘Sure,’” says Johns. “People weren’t