Twenty years ago, a pasture in Costa Rica was nearly barren farmland, choked by invasive grasses. Today, it blooms anew with a rich tangle of jungle plants. The magic ingredient for this resurgence? Oranges.

In the mid-1990s, Del Oro, a newly established orange juice manufacturer in Costa Rica was looking for a way to get rid of the rinds and pulp left over after juice extraction. They planned on building an expensive processing plant, but two ecologists from the University of Pennsylvani