Human Impact on Ecosystems (Edexcel IGCSE Geography)

Impact of Farming Systems

Spec point — 4GE1-S6.068

• To obtain food humans use and modify the ecosystems through farming

• There are four groupings commonly used to categorise farming:

  • Categorisation by outputs

    • Arable (the cultivation of crops) and **pastoral **(raising livestock)

  • Categorisation by whether a profit is made****

    • Commercial (farming to gain profit) and subsistence(farming to feed farmer and family)

  • Categorisation by the inputs

    • Extensive (a farm with low inputs or yields per hectare) and intensive(a farm with high inputs or yields per hectare)

  • Categorisation by location

    • Nomadic (farmers moving seasonally with crops/livestock) and sedentary(where the same area of land is farmed every year)

• A farm that has both livestock and grows crops is a mixed farm

Farming systems

• All farms are systems, they have inputs, processes and output

Diagram to illustrate a farm system

Impacts of farming systems

• All farming systems impact the ecosystem in which they are located

• Some have more impact than others

• Commercial arable and pastoral farming tends to:

  • increase monocultures which reduces diversity because the animals have no access to a wide range of foods
  • mean that nutrient cycling is dependent on fertilisers added to the soil, which may be natural (manure) or artificial fertilisers
  • modify the ecosystem with inputs of seed, fertiliser, pesticides, herbicides and the use of machines
  • reduce the links within food webs
  • reduce the amount of biomass

• Intensive farming has more impacts than extensive farming because it is more likely:

  • to rely on high levels of fertilisers and pesticides
  • to be a monoculture which reduces biodiversity
  • have increased use of machines

• Subsistence and nomadic farming have less impact on the ecosystem because they tend to be smaller scale and make less use of:

  • machines
  • fertilisers
  • pesticides

Exam Hint Remember farms do fit more than one category. For example, a sheep farm in Cumbria, UK would be categorised as pastoral, commercial, extensive and sedentary.