India, Sept. 29 -- In March 2018, scientists deposited approximately 30 dump truck loads of coffee pulp on an abandoned pasture in southern Costa Rica. They spread about 360 cubic meters of the material into a layer roughly 0.4 to 0.5 meters deep across a 35-by-40-meter plot and left an adjacent plot of similar size untreated as a control. Two years later, canopy cover above 2 meters had reached more than 80 percent in the treated plot, while the control remained far less developed.

The results were reported in the 2021 study Coffee pulp accelerates early tropical forest succession on old fields, by Rebecca J. Cole and Rakan A. Zahawi. The experiment was designed to test whether coffee pulp could overcome some of the barriers that slow f...