impl of defo & farmin practices on C s in soil & nutrient c

• Implications of deforestation and farming practices in the Amazon basin on the carbon store in soil and nutrient cycle


  1. Burning of forests releases nutrients in the biomass store, producing a layer of nutrient-rich material above the nutrient-poor soil

  2. Cleared area is quickly planted and able to be agriculturally productive for a few years before nutrient store is depleted and large amount of fertiliser is needed to maintain its carrying capacity

  3. When use of fertiliser is no longer economical, the land is abandoned or grasses are planted for cattle grazing

  4. Land is only marginally productive at this stage, supporting a limited number of cattle
• Deforested land has poor nutrients in the soil because the input to the nutrient cycle by leaf litter has disappeared alongside the forest trees
• Effects of deforestation on water and nutrient cycles

  1. Without the protection of rainforest canopy, interception loss is removed as well as water recycling to the atmosphere by transpiration from leaves

  2. More rain reaches the ground surface and infiltrates into the soil, causing increased leaching of nutrients

  3. This further explains why there is poor nutrient content in the soil on deforested land

  4. Overland flow also became more common, causing soil erosion
• Because nutrients quickly become depleted, new areas of the rainforest need to be deforested to provide fertile land for agriculture or cattle ranching
• This causes deforestation to spiral out of control
• Using deforested land for agriculture is inherently unsustainable