Here's what the research says about shade-grown coffee (real stories from the field)

Here at Beautiful Beast Coffee Co., we talk a lot about the advantages of shade-grown coffee. 

But it's easy to "talk" about the advantages. It's much harder to back up what you say with actual scientific evidence.

Fortunately, that is exactly what I'm doing below.

I have found various research papers that looked at the impacts of shade-grown coffee. I've organized the studies into four sections:

• An increase in biodiversity.
• Soil health
• Controlling pests
• Increasing pollination

And there is a bonus section at the bottom about what shade-grown coffee means for farmers. :)

An increase in biodiversity:

The trees that provide shade on coffee farms offer excellent habitat for wildlife and are often located where the surrounding areas have been devastated by deforestation. The forest-like conditions of shade-grown coffee farms allow many different species to thrive.

Scientific Studies:

• As coffee farming shifts from traditional shade-grown methods to intensive monocropping, there is a noticeable decline in the diversity of trees, birds, small mammals, amphibians, and ants. (*Perfecto, Greenberg, Gallina as cited in Jha et al. 2011).

• Traditional shade-grown coffee farms serve as habitats for diverse invertebrate communities, including flies, bees, butterflies, wasps, bugs, ants, spiders, and other species. (*Philpott et al 2006, Ambrecht et al 2005, Moguel and Toledo 1999).

• Birds spending the winter on Bird Friendly-certified farms in Venezuela exhibited better body condition than those in nearby forests, which is essential for their spring migration north. This improvement is likely due to the abundance of small-fruited plants beneficial to birds, along with flowering plants that attract insects, providing a rich and varied food supply. (*Bakermans et al. 2009).

• As many as 65% of cerulean warblers banded in Venezuela one year were found returning to the same coffee farms the next year. This highlights the significance of shade-grown coffee farms, and the birds' strong tendency to return to high-quality habitat during migration. (*Bakermans et al. 2009).

Soil Health:

Most coffee grown in the tropics is grown on steep, mountainous landscapes in areas with lots of rain. Having tree cover helps minimize soil erosion and stabilize slopes. 

Scientific Studies:

• Traditional shade-grown coffee farming, which involves minimal tillage and reduced use of agrochemicals, helps preserve soil structure and maintain its fertility. (*Iijima et al 2003, Ataroff and Monasterio 1997).

• In Venezuela, sun-grown coffee farms experience twice the amount of soil erosion compared to shaded coffee systems. (*Ataroff and Monasterio 1997).

• A study in Nicaragua found the following (*Rice, 1990):
  • Open-sun coffee farms experienced over 2.5 times the soil erosion compared to shade-grown coffee on the same hillsides. 

• • In Nicaragua, the soil under shaded coffee farms had 18% higher carbon content—an important indicator of soil fertility—than soil in coffee farms with little or no shade. 

• • Additionally, fertility levels were found to be 19% higher in shaded coffee farms compared to those with minimal or no shade. 

• • Soil moisture levels in sun-exposed coffee farms can be up to 42% lower than in farms with a dense canopy of foliage.

Controlling Pests:

One of the best parts of shade-grown coffee is that these farms operate more like an ecosystem with diverse food webs. The increased number of birds, lizards, amphibians, and beneficial insects act as predators of many destructive coffee pests. This results in no or lower amounts of pesticides needed.

Scientific Studies:

• In a study conducted in Jamaica, researchers found that when birds were prevented from accessing coffee plants, the percentage of coffee fruits infested by the coffee berry borer—one of the crop's most destructive pests—increased by 70%. (*Kellerman et al. 2008).

• The same Jamaican study also revealed that migratory birds accounted for 73% of coffee berry borer predation. The main predators were neotropical migratory species, including black-throated blue warblers, American redstarts, and prairie warblers. (*Kellerman et al. 2008).

• In Chiapas, Mexico, excluding birds from shade-grown coffee farms led to a rise in arthropod populations, including caterpillars and other leaf-chewing insects. Their numbers increased by 30% during the dry season and 64% in the wet season, posing a greater risk of leaf damage, reduced photosynthesis, and potential disease spread. (*Williams-Guillen et al. 2008).

• In plantations with a canopy cover of at least 40%, many weeds can be fully suppressed, reducing the reliance on harmful herbicides. (*Beer; Muschler as cited in Jha et al. 2011).

• The problematic coffee berry borer is eaten by birds, ants, spiders and bats. Coffee farms that support these predators by offering diverse shade forests reduce berry losses. (*Larsen and Philpott; Armbrecht and Gallego; Perfecto and Vandermeer; Velez; Kellermann; Philpott, personal communication with K. Williams-Guillen as cited in Jha et al. 2011).

• Certain fungal diseases, such as coffee leaf rust, can seriously impact coffee yields by damaging the plants. However growing coffee in the shade can hinder coffee leaf rust by slowing down the wind, which is how the fungus spreads its spores. (*Soto-Pinto; Schroth as cited in Jha et al. 2011)
  

Increasing Pollination:

Scientific Studies:

• In Costa Rica, it was shown coffee farms that have flowering plants within their borders have higher bee diversity than those without. Not surprisingly, having bees around to pollinate coffee plants has shown an increase in coffee yields (*Klein et al.  2003a, Klein et al.  2003b). 

• When a coffee farm has more bees around it leads to a better harvest. More honeybee visits correlate with a higher coffee fruit weight and fruit set (the percentage of coffee flowers that develop into fruit) (*Manrique and Thimann; Roubik; Raw and Free as cited in Jha et al. 2011).

• Bee species diversity increases the percentage of coffee flowers that develop into fruit. For example, in Indonesia, coffee flowers that were visited by 20 bee species or more had a 90% chance of fruiting. While coffee flowers visited by three species of bees only had a 60% chance (*Klein et al. 2003a, Klein et al. 2003b).

Impacts for farmers:

One of the best parts about drinking shade-grown coffee is that it helps farmers. While there are no scientific studies regarding this topic, here are a few reasons.

• Coffee farms that practice sustainable methods often welcome visitors eager to learn about the cultivation process and the environmental benefits of shade-grown coffee. This tourism can provide an additional income stream for farmers and their communities, enhancing the overall economic stability of the region.

• The reduced usage of pesticides and fertilizers is great news for farmers and local communities. Shade-grown coffee farms are much safer to live near than a sun-grown coffee plantation, as the water, soil, and air are not contaminated with these poisons.

• Shade-grown coffee farms often provide additional income opportunities for farmers, such as lumber, medicinal plants, and fruits that grow on the diversity of tree species.

 

References:

Ambrecht, I., L. Rivera and Perfecto, I. 2005. Reduced diversity and complexity in the leaf-litter ant assemblage of Colombian coffee plantations. Conservation Biology, 19(3): 897-907.

Ataroff, M. and M. Monasterio, 1997. Soil erosion under different management of coffee plantations in the Venezuelan Andes. Soil Technology 11:95-108.

Bakermans, M. A. Vitz, A. Rodewald, and G. Rengifo, 2009. Migratory songbirds use of shade coffee in the Venezuelan Andes with implications for conservation of cerulean warbler. Biological conservation 142:2476-2483.

Iijima, M., Y. Izumi, E. Yuliadi, Sunyoto, Afandi and Utomo, M. 2003. Erosion Control on Steep Sloped Coffee Field in Indonesia with Alley Cropping, Intercropped Vegetables and No-Tillage. Plant Production Science, 6(3): 224-229 pp.

Kellerman, J., M. Johnson, A. Stercho and S. Hackett, 2008. Ecological and Economic Services Provided by Birds on Jamaican Blue Mountain Coffee Farms. Conservation Biology, Volume 22, No. 5, 1177-1185

Moguel, P. and V. Toledo. 1999. Biodiversity Conservation in Traditional Coffee Systems of Mexico. Conservation Biology, 13 (1): 11-21.

Philpott, S., W. Arendt, I. Armbrecht, P. Bichier, T. Dietsch, C. Gordon, R. Greenberg, I. Perfecto, R. Reynoso-Santos, L. Soto-Pinto, C. Tejeda-Cruz, G. Williams-Linera, J. Valenzuela, and J. Zolotoff 2008. Conservation Biology 22(5):1093-1105.

Jha, S., C. Bacon, S. Philpott, R. Rice, V. E. Méndez, & P. Läderach, 2011. A Review of Ecosystem Services, Farmer Livelihoods, and Value Chains in Shade Coffee Agroecosystems. In Integrating Agriculture, Conservation and Ecotourism: Examples from the Field 141–208.

Jha, S., C. Bacon, S. Philpott, R. Rice, V. E. Méndez, P. Läderach, & Rice 2014.
Shade Coffee: Update on a Disappearing Refuge for Biodiversity. Bioscience 64: 416-428.

Klein, A., I. Steffan-Dewenter and T. Tscharntke, 2003a. Pollination of Coffea canephora in relation to local and regional agroforestry management. Journal of Applied Ecology 40:837-845.

Klein, A., I. Steffan-Dewenter and T. Tscharntke, 2003b. Fruit set of highland coffee increases with the diversity of pollinating bees. Proceedings of the Royal Society of London270:955-961.

Philpott, S., I. Perfecto and Vandermeer, J. 2006. Effects of Management Intensity and Season on Arboreal Ant Diversity and Abundance in Coffee Agroecosystems. Biodiversity and Conservation, 15: 139-155 pp.

Rice, R. 1990. Transforming Agriculture: The Case of Coffee Leaf Rust and Coffee Renovation in Southern Nicaragua. Dissertation in Geography, University of California, Berkeley. 304 pp.

Williams-Guillen, K., I. Perfecto, J. Vandermeer, 2008. Bats limit insects in a neotropical agroforestry system. Science 320:70