AGOTIME BEH, Ghana — After he graduated from university, Vozbeth Kofi Azumah was reluctant to tell anyone — even his mother — what he planned to do for a living. “I’m a farmer,” he said, buzzing his ...

According to geologist David Montgomery, author of Dirt: The Erosion of Civilizations, the world loses roughly 23 billion tons of good soil each year. At this rate, it will all be gone within 150 ...