While most Kenyan farmers grow coffee in open sunny fields, others have embraced shade-grown coffee. This is a form of coffee production that grows the crop under a tree canopy.
Previously thought of as limiting production, this form of coffee growing is proving beneficial in climate change mitigation, natural pest reduction, provision of essential nutrients, and organic fertilisation.
Climate Change Mitigation
Coffee is classified amongst the most high-risk crops due to climate change. At current rates, up to half of coffee-growing land is expected to be unsuitable by 2050. This is expected to hit 90 per cent by 2080 particularly in Kenya, Ethiopia, and Sudan.
Providing coffee with a tree canopy creates microclimates– a key climate change adaptation strategy that helps guard against its negative effects on coffee plants. In shaded plantations, the soil moisture content is up to 42 per cent higher than unshaded ones.
Shade trees also help reduce soil erosion, particularly in sloping land.
Pest Reduction
Trees grown around coffee plants provide a home to various animal species. They form complex food webs with birds and mammals contorlling pests by eating potentially harmfull insects.
A single bird has been estimated to protect 23-65 pounds of coffee per hectare every year from pests.
In one study, coffee plantations in which birds were excluded had a 70 per cent higher proportion of coffee fruits infected by the Coffee Berry Borer (CBB). The economic value of birds as biological predators on CBB was worth Sh10,050/Ha.
Organic fertilisation & Nitrogen fixation
Shaded by rows of trees, Paul Muthuiya’s two-acre coffee farm in Equator Meru is as cool as it is fruitful. The veteran farmer who’s been in the trade since 1984 counsels farmers to grow trees that do not compete for nutrients with coffee and whose leaf litter decomposes quickly such as Cordia africana. This increases the soi’sl nutrients.
“Farmers should avoid species like grevillea whose leaves take time to decompose. Trees should also be planted on the bounderies of the plantation not amongst coffee bushes to avoid competition for nutrients,” he said.
According to World Agroforestry, trees such as Erythrina abyssinica are grown as coffee shade trees due to their nitrogen-fixing properties. This supplies plants crucial nutrients they couldn’t acquires from the air by themselves.
Coffee farmers growing coffee under a tree canopy cover of at least 15 per cent can also acquire certification from the Rainforest Alliance or the Bird Friendly coffee certification program unlocking growing opportunities to earn premium specialty coffee prices.