Native in the tropics and subtropics, the coffee plant can have 30,000 to 40,000 flowers blossoming in a year. After the first shower of the rainy season, right after dry season, the coffee plants start flowering. The beautiful flowers with 5 to 6 white petals last only a few hours and wilt as soon as fertilization has taken place. After three to four days, the flowers drop off on the ground, enabling new green beans to emerge from the same bud on the branch of the coffee shrub. To note the only two types of coffee plants cultivated, Coffea Arabica coffee plant is self-pollinating, whereas the Robusta coffee plant depends on cross pollination. However, David W. Roubik of the Smithsonian Tropical Research Institute in Balboa, Panama, reports “coffee-bean yields skyrocket when the shrubs’ flowers are visited by pollinating insects.”

That means the coffee flowers have to be seen by pollinators in a few hours to be able to have a fruitful life then. Keep in mind Insets cannot see or identify the color of white with their eyes, so how do the coffee plants survive? How do their flowers attract their pollinators?  Through evolution, the coffee flowers develop sweetly fragrance, similar to the scent of jasmine, open at night/early in the morning, so their pollinators easily find them by following their beautiful smell and get pollination work done. Coffee plants survived finally, and I shall respect them simply for all of hard work they have to do…

http://justaboutcoffee.com/index.php?file=coffeetree

https://www.sciencenews.org/blog/food-thought/buzz-over-coffee

http://www.s-caffe.com/en/home/coffee-culture/coffee-encyclopaedia/the-coffee-flower.html

Coffee is grown from the Tropic of Cancer to the Tropic of Capricorn. At these latitudes, constant processes of weathering and erosion in the warm humid conditions have leached the soils of essential nutrients. The Encyclopedia of Soils in the Environment, the tropical soils section describes common nutrient deficiencies in tropical soils as, “The most frequent limitations result from insufficient plant-available nitrogen, phosphorus, potassium, calcium, or magnesium” (Buol 187-195). The journal goes on to explain about how each of these nutrients are added to soil through weathering of minerals and how they can be bound up or leached to the extent that they’re no longer available to plants; For example, Potassium comes from micas and feldspar which are easily weathered and “consequently are seldom present in materials that have been repeatedly transported and deposited on the land surface”(187-195). Phosphorous tends to get bound up very tightly to Iron and Aluminum and is virtually inaccessible to plants. Soil that is nutrient rich is very valuable for plant life and thus agriculture, humans, and coffee production in the tropics. We’ve frequently mentioned in class how volcanic debris are very important sources of soil nutrients in the tropics for both coffee and cacao. Buol adds areas where tectonic uplifting has raised “limestone, base-rich igneous, rock and metamorphic rock” and “floodplains and deltas to the list” of important agricultural areas. These are the mineral-fertile areas where agriculture makes a lot of sense. The two cultivated varieties Arabica and Robusta can be grown at a wide elevation range which means coffee could potentially take advantage volcanic soils at high altitudes of or rich soils at lower altitudes. Both species can also be grown as part of an agroforestry system. We found a couple interesting studies on the interaction between soil and different coffee growing systems: agroforestry or monoculture. One measured carbon sequestration in soil around coffee production. This study found that soil organic carbon was significantly higher in an agroforestry system than a monoculture system and that Robusta grown together with non fruit trees had the highest soil organic carbon concentration of any of the coffee systems they looked at (Tumwebaze & Byakagaba Agriculture, Ecosystems & Environment). A study on water erosion in volcanic soils in coffee farms in Sumatra found that “The runoff coefficient under monoculture coffee remains on average significantly higher (10–15%) than under forest (4%) or under shade coffee systems (4–7%)”(Verbist et. al. CATENA). A study on Phosphorous in soils in coffee farms found that Agroforestry coffee systems had a greater proportion of organic phosphorous to inorganic phosphorous. (Cardoso et. al. Agroforestry systems).

Every second, people around the world drink more than 26,000 cups of coffee. some of them may care only about the taste, and some of them may use it as a way to wake them up in the morning.

To humans, coffee is a valuable beverage crop due to its characteristic flavor, aroma, and most importantly the stimulating effects of caffeine.  While we appreciate the diverse fragrances of a cup of coffee and the stimulation of the world’s most popular drug, we know little about its origin and forget coffee is the result of hundreds of thousands of years of plant evolution.

As a crop, high land Coffee Arabica and low land Robusta are the products of the only two coffee species cultivated now in over 50 tropical countries. However, according to IRD researchers, “a total of nearly 120 wild Coffee species exist starting from their origin in Lower Guinea, colonized the whole of Equatorial Africa and the Madagascar region in 400,000 years ago.”  According to this French research organization, The true origin of coffee plants is neither the legend of the dancing goats in Ethiopia, described since the 8th Century, nor the theory of coffee species originating on the Horn of Africa before the Gondwana super-continent broke up more than 100 million years. (Courcoux)

Over the past 400,000 years, cycles of glaciation happened every 100,000 year that result in a high variability in climate and intense phases of cooling. However, during this period, the flora has survived and spread in refuge zones/biodiversity hot spots (regions suitable for forests at altitude or near oceans), such as Lower Guinea. The coffee species then diversified.

https://en.ird.fr/the-media-centre/scientific-newssheets/347-a-new-history-of-coffee

http://www.lahistoriaconmapas.com/atlas/africa+map/guinea-africa-map.htm

Agroforestry Coffee Magic

Integrative Question: Using a permaculture design lens a coffee farm can be very sustainable. Our group believes agroforesrty or shade coffee farming could be a reliable system. Agroforestry means growing crops with surrounding trees and shrubs for a farm with diverse benefits for the ecosystem (farmer included). In a coffee agroforestry system, erosion is reduced, nutrients are cycled more efficiently, diversity of crops for food and materials are available to the people : this aligns with earth care and people care (Verbist et. al. CATENA) (Cardoso et. al. Agroforestry systems). Soil carbon sequestration is higher in agroforestry systems, and can contribute to mitigating climate change (Tumwebaze & Byakagaba Agriculture, Ecosystems & Environment). We would plant robusta and arabica species because they each have different benefits, hardiness and yield vs flavor and market price. If the climate change became too hot for arabica, we would still have robusta to rely on. We would also have fruit trees growing between the coffee plants to provide shade and food. One of these fruit trees would be cacao which could be food or another export. Ideally, the diversification of this system would ensure the community always has as much food as it needs and coffee and cacao to trade. Eventually, value can be added if farmers choose to make chocolate locally to keep the added value local.