Pruning residue management
The way crop residues are managed can greatly influence the levels of emissions.
If residue is wet and left in a pile untreated, it emits methane as it degrades which is 23 times more potent of a GHG than carbon.
If it is mulched and spread on the farm or composted and aerated (for the pulp), fewer emissions are generated.
Pruning: trees and coffee
Coffee plants also sequester carbon. However, carbon is released when the trees are pruned, trimmed, or cut.
So the amount sequestered has to be reduced by the amount that is pruned.
Fertiliser use
Nitrogen fertilizers are one of the highest sources of emissions on coffee farms due to the nitrous oxide created which is 300 times more potent of a GHG than carbon.
Interestingly, heavy use of organic fertilizers causes similar levels of GHG emissions as inorganic fertilizer for on farm use – because of the nitrous oxide created - whether organic or inorganic nitrogen sources.
Type of shade management
Coffee farms can be managed in various ways - from monocultures of coffee plants to coffee grown in the understory of forests and all the gradients in between.
Coffee monocultures are called "sun coffee" to distinguish from coffee grown interspersed with other types of trees and vegetation called “shade-grown coffee” or just “shade coffee” for short.
We have grouped these management systems into three broad categories using percent canopy cover as the defining metric.
Production of fertiliser
Did you know that for inorganic (aka synthetic) fertilizers, the production releases almost as much emissions as the use? Huge amounts of energy and heat are required to manufacture chemical nitrogen compounds.
Fuel use: equipment and vehicles
On most small-holder coffee farms, minimal energy is used. Fuel is needed for equipment such as weed whackers or chainsaws, but that’s really it. On larger farms, fuel is used to transport workers to different areas of the farm.
PATIO DRYING and RAISED BEDS
There are no emissions associated with natural processed coffee at this stage because the coffee is not depulped (no compost or waste) or washed after fermentation (no wastewater).