#203Mulching
203⸱AConcept
- Balances soil humidity and temperature
- Reduces erosion
- Suppresses weed growth
- Improves soil structure and organic matter
- Improves soil life
- Improves plant nutrition
Mulch is a layer of dried or rotten plant residues to cover the soil between crop rows and trees. All types of plant material can be used, such as dried grass, stalks, haulms, straws, or also decomposed organic materials such as compost.
Bare and unprotected soil can lead to soil erosion through wind and rain and high soil temperatures due to direct sun exposure and dryness. Climate change is increasing these impacts.
Mulching helps adapt to these climate change impacts. It protects the soil from direct sunlight and rain impacts, helps to reduce soil erosion, and keeps the soil moist and temperate. It suppresses weed growth and as mulching material decomposes, it releases nutrients to the soil. At the same time, it improves the uptake of nutrients by the trees by ameliorating the soil structure in the long run. An indirect benefit of mulch is that it reduces the incidence and severity of pests and diseases. This is, first, because it reduces moisture and nutrient stress for the plant which increases its resistance, secondly, because it improves the biodiversity in the soil which helps against soil-borne pathogens.
203⸱BVideos
203⸱CTo be considered
Some mulching materials might introduce pests and weed seeds into the coffee field. Coffee husks should be avoided as they can carry both problems. Before using coffee husks for soil improvement, they should undergo a decomposition or fermentation process as in the production of Compost or Bokashi. In that way, potential infections are rendered harmless.
To avoid the uncontrolled spread of mulch plants within the coffee plots, they should be cut and spread while they are NOT bearing seeds.
Depending on the local conditions, mulching might be a potential fire hazard during the dry season. To prevent mulch fires, avoid setting fire for land clearing. Also, avoid discarding lighted materials such as cigarettes or matches into a mulched field.
An alternative to the here described mulch is Cover crops (Living mulch). Cover crops have their own variety of benefits, protecting the soil and coffee trees as cut mulch material does, but needing no extra space to produce biomass as it is integrated into the coffee field. Additionally, some cover crop species fix nitrogen and integrate it into the soil, directly benefiting the coffee.
However, if external mulch material is available, the here-described mulching is a practical way to help prepare the coffee field for the mentioned climate change impacts.
Timing: The mulch material can be brought out at any point during the year. The timing is however ideal right before the rainy season or immediately after 2-3 rains. In that way, the mulch layer can trap and conserve the incoming rainwater.
203⸱DImplementation
Materials
Mulch materials can e.g. be stovers, haulms, leaves, or dry grass of:
- Maize
- Sorghum
- Soybean
- Banana
- Pennisetum americanum (Millet)
- Raphanus sativus L. (Fodder beet)
- Lupinus albus (Lupine)
- Cenchrus purpureus/ Pennisetum purpureum (Elephant/Napier grass)
- Urochloa ruziziensis (Brachiaria)
- Panicum maximum (Guinea grass)
- Mucuna pruriens (Velvet bean)
- Crotalaria sp. (Crotalaria)
- Cajanus cajan (Gandul, Feijão Guandu, Pigeon pea)
- Tephrosia genera (if used at young / fleshy stage)
- Etc.
203⸱1Procedure
203⸱2
Brachiaria mulch in Brazil
Make sure that the mulch does not touch the trunk of the coffee tree to avoid infections and rotting. This precaution helps prevent, for example, collar rot and keeps away ants and parasites that may try to use the mulch material as a bridge to attack the tree.
203⸱3
- The dry mulch should be continuously maintained and renewed every season.
203⸱EEconomic benefits
Lower labor costs
This tool might cause some extra workload and material costs in the beginning. However, its advantages ultimately result in lower labor requirements and therefore lower costs.
Lower irrigation demand
This tool reduces irrigation requirements and thereby costs.
Lower herbicide costs
This tool reduces the demand for pesticides and therefore saves input costs over time.
203⸱FGreen benefits
Less irrigation needed
This tool helps conserve water in the production system. This saves water as a scarce resource.
Less herbicides needed
This tool reduces the need for herbicides. This reduces water pollution, protects the ecosystem, improves soil life, and saves resources.