Overview
- In the late 1990s ecologists working with juice company Del Oro spread about 12,000 tonnes of orange peels and pulp over a roughly three‑hectare degraded pasture inside Área de Conservación Guanacaste.
- A rival firm, TicoFruit, sued and the Costa Rica Supreme Court ruled the dumping improper, which halted the program and left the site unmanaged for years.
- Princeton researcher Timothy Treuer revisited the parcel in 2013 and found dense tree growth, and a 2017 peer‑reviewed study reported a 176% rise in aboveground biomass and stronger soil fertility compared with a nearby untreated plot.
- Scientists attribute the recovery to the peel layer killing invasive grasses, releasing nutrients as it decomposed, boosting soil organic matter and improving moisture retention, and some researchers say the approach could sequester carbon at very low apparent cost.
- Researchers and conservationists stress the result is a small, location‑specific case study not a ready method for large‑scale restoration because of the legal ban in the park, unique local conditions, and the need for careful governance and further trials.