When Zemede Asfaw was growing up on a farm in eastern Ethiopia, he soaked up plant lore and other traditional knowledge the way a tree takes in sunlight and converts it to energy. “I knew the crops, and the wild plants, and the fruits and other things,” says Zemede, who goes by his given name. The practical methods he learned covered every aspect of farming: Instead of stone walls or wire fences, plant field edges with darker crops, so the bold colors of red sorghum, for example, create a clear…
