In 1998, Costa Rica spread 12,000 tonnes of orange waste; 16 years later, forest biomass rose 176%

Aerial view of the orange peel-treated area (right) and untreated pasture (left), surveyed by Princeton researchers. In the late 1990s, an unusual conservation experiment began in Costa Rica when ecologists proposed using orange peels and pulp to help restore a badly degraded piece of land inside a national park.For this, orange juice company Del Oro and ecologists Daniel Janzen and Winnie Hallwachs, worked with the Area de Conservacion Guanacaste (ACG), or Guanacaste Conservation Area. According to Princeton University, the company had recently started production near the northern border of the conservation area and was looking for a way to deal with its orange waste.Janzen and Hallwachs proposed a deal wherein Del Oro would donate some of its forested land to the ACG. In return, the company could take its orange peel waste to a degraded pasture inside the park, where it could break down naturally.After the agreement was signed, around 1,000 truckloads of orange peels and pulp, totalling about 12,000 metric tonnes, were spread across the degraded land.Over the next several years, the area changed dramatically. A place that had once been covered by exposed rock and dead grass becam...