key points

  • More than 95% of humanity’s present food supply is produced from the soil.

  • 40% of soil used for agriculture globally is classed as degraded or seriously degraded – i.e. 70% of the topsoil has been lost.

  • The UN FAO has projected that for the planet, net land under crops may have to increase by 700 million hectares by 2050 to meet predicted global food needs.

  • The loss of food security – through climate change or the loss of soil and water resources – is a major factor in people deciding to quit their homelands in search of new life, either as economic migrants ahead of a crisis they have foreseen or as refugees fleeing a disaster.

Source

 

definitions

 

context

  1. Read 161-163 Patterns & Change Book
  2. Make notes
  3. Review your notes. Identify and highlight key facts.
 
 

CAUSES OF SOIL DEGRADATION

  • Water & wind erosion
  • Climate and land use change
  • Artificial fertilisers and pesticides
  • Physical degradation
  • Overgrazing
  • Chemical degradation
  • Deforestation
  • Biological degradation
  1. In groups, write the causes of degradation on to post-it notes
  2. Organise these on a blank piece of paper to form a hierarchy of importance (2 at the top, 4 in the middle, 2 at the bottom)
  3. Share with the class and justify your choices.
  4. Put to one side and complete the task below.
 
 
  1. Read pp 164 - 170 Patterns and Change book
  2. Complete the grid above with condensed notes and illustrations
  3. Review your grid and modify the position of the post-its
  4. What did you change and why?
 
 

EXAM PRACTICE

Describe the relationship between the level of poverty and the level of soil degradation shown on the diagram. [3 marks]

 

Answers

Possible descriptions might include:

  • low levels of poverty have lower levels of high soil degradation/high levels of poverty have higher levels of high soil degradation
  • low levels of poverty have the most improving soil
  • low levels of poverty appear to suffer the most from moderate soil degradation.

Accept other valid descriptions.

Reserve the final [1 mark] for some attempt at quantification/use of the data.

 

management strategies

Visual poster promoting hygiene in rural Ghana, where literacy levels can be an obstacle to understanding education campaigns.

Visual poster promoting hygiene in rural Ghana, where literacy levels can be an obstacle to understanding education campaigns.

  1. Read pp 170-173 Patterns & Change Book
  2. Choose 6 cropping techniques from the bullet point list.
  3. Create a publication targeted at farmers in Sub-Saharan Africa highlighting the dangers of soil degradation and how to avoid it using management strategies.
  4. 38% of adults in Sub-Saharan Africa lack basic literacy skills (source) - your publication will need to be very visual and use simple English with symbols.
  5. You can create an electronic or paper version of your publication.
 
 

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