Below is a summary table:
|Yield||Lower (~25 - 40%)||Higher|
|Coffee Plants per Hectare||1000 - 2000||3000 - 7000|
|Kilograms per Hectare per Year||550||1600|
|Lifetime of Coffee Plants||24 - 30 Years||12 - 15 Years|
|Number of Other Crops||High||Low/None|
|Flavour||Less Bitter||More Bitter|
|Producer||Mostly Small-scale Growers||Mostly Large-scale Growers|
|Number of Bird Species||150||20 - 50|
|Proportion of Avifauna in Normal Forest||2/3||~1/10|
|Number of Mid-Sized Mammal Species||24||Almost None|
|Number of Other Animal Species||More Ants, Beetles, Epiphytes, Amphibians, and Other Species||Fewer Ants, Beetles, Epiphytes, Amphibians, and Other Species|
|Source: Northwest Shade Coffee Campaign|
Biodiversity: Shade plantation supports native flora and fauna. The canopy trees become home for migratory birds. In Mexico, it is found that cacao and coffee shaded plantations support over 150 species of birds, a number that is only slightly lower than the number found in undisturbed tropical forest. Some coffee plantations in Nicaragua have been found to contain over 25 species of plants. In India, coffee plantations in the Western Ghats have supported many threatened flora and fauna, such as the cycas plants, tigers, elephants, sambars, and other mega fauna. Hence, it is obvious that shade plantations maintain biodiversity.
On the other hand, studies in Colombia and Mexico found that sun plantations have 94-97% less bird species than shade plantations. When coffee is the only plant species being grown and with agrochemicals being used more frequently, sun plantations simply do not maintain biodiversity.
Agrochemicals: In order to protect the environment, a minimum use of insecticides, fungicides and herbicides is required. The traditional cultivar of coffee can be weakened by temperature fluctuations caused by sunlight, hence the need for the shaded plants. Also, placing coffee plants amongst other plant species can reduce susceptibility to pests. Though "technified species" have been grown, which are more resistant to sunlight, technified plantations still require more agrochemicals than shade plantations.
Soil conservation: Due to a lack of canopy, the soil in technified plantations is exposed to rain, hence more erosion occurs. Erosion also occurs when establishing a new plantation or growing new crops. Since the lifespan of a technified coffee bush is only half that of a sun-grown bush, technified plantations require frequent renovation, which results in further soil erosion.
Fertiliser: Technified varieties require more fertiliser. On the other hand, dead leaves from the shade trees can supply up to 95% of the annual nitrogen requirement for coffee bushes planted at low densities. Soil in legume-shaded plantations also gets nitrogen from these legume trees. Hence, technified plantations require a larger input of fertiliser than shaded plantations.
Natural Resources Defense Council
Environmental Media Services
The Trade and Environment Database
“Shade vs. Sun Coffee: A review” by Shawn Steiman
INeedCoffee – articles by Dr. Anand Titius and Geeta N. Pereira
Simthsonian National Zoological Park