Researchers from Switzerland and Hawaii claim they found a way to use coffee pulp to help regenerate forests that have been destroyed as a result of agricultural processes.
Coffee pulp is abundant as a by-product of the production process
A new study found that coffee pulp, a by-product of coffee production, can be used to accelerate tropical forest recovery on post-agricultural land. The results were published in the journal Ecological Solutions and Evidence of the British Ecological Society.
In the study, researchers from ETH Zurich and the University of Hawaii distributed 30 dump truck loads of coffee pulp over a 35 × 40 m area of degraded land in Costa Rica and marked an area of similar size with no coffee pulp as a control.
„The results have been dramatic,” said Dr. Rebecca Cole, lead author of the study. „The area treated with a thick layer of coffee pulp turned into a small forest in just two years, while the control field continued to be dominated by alien grazing grasses.”
After just two years, the area treated with coffee pulp had 80 percent coverage compared to 20 percent in the control area. The canopy in the coffee pulp area was also four times higher than that of the control area.
The researchers also found that after two years, nutrients including carbon, nitrogen and phosphorus were significantly increased in the coffee pulp treated area compared to the control. This is a promising finding, as former tropical agricultural areas are often severely degraded and poor soil quality can delay forest succession for decades.
„This case study suggests that agricultural by-products can be used to accelerate forest restoration in degraded tropical areas,” said Dr. Cole.
„In situations where these by-products are costly to the agribusiness to process, using them to restore to meet global reforestation goals can be a win-win scenario.”
As a widespread high-nutrient waste product, the research team believes that coffee pulp can be a cost-effective strategy for forest restoration.
How did you do that?
The study was carried out in the district of Coto Brus in southern Costa Rica on a former coffee farm that is being restored in forests for protection. In the 1950s, the region was freed from deforestation and land conversion into coffee cultivation and pasture land, with the forest area reduced to 25 percent by 2014, according to the scientists.
In 2018, the researchers defined two areas with a size of about 35 × 40 m, spreading coffee pulp on one area to a half-meter-thick layer and leaving the other as control.
The researchers analyzed soil samples for nutrients immediately before the coffee pulp was applied and again two years later. They also recorded the species present, the size of the logs, the percentage of forest floor cover and used drones to map the canopy.
Dr. Cole warns that as a case study with two years of data, more research is needed to test the use of coffee pulp to aid forest restoration. “This study was only conducted at one large site, so further testing is needed to see if this strategy works in a wider range of conditions.
“The measurements that we share are only from the first two years. Longer term monitoring would show how the coffee pulp affected the soil and vegetation over time. Additional tests can also assess whether coffee pulp replication is causing undesirable effects. „
However, the research team emphasizes that one limitation on the use of coffee pulp or other agricultural by-products is that its use is mostly limited to relatively flat and accessible areas where the material can be delivered and that there is a risk of the nutrients being added Can be managed to be flushed into nearby water catchment areas.
In some areas, however, there is hope that this widespread waste product can be put to good use and help reverse some of the harmful effects of deforestation on the world’s great habitats.
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