desertification P1

• Why is exposed soil easily removed by wind or water?

  There are no roots to hold it together
• What happens to nutrients in the soil during desertification?

  Nutrients in the soil are lost
• What are the two main causes of desertification according to the video?

  Climate change and human activities
• Why does the removal of trees lead to desertification?

  It leaves the soil exposed
• What happens during over cultivation?

  All the nutrients in the soil are used up
• What is drip irrigation?

  Applying water directly to plant roots
• How do trees act as windbreaks?

  Reducing wind erosion
• How do trees stabilize the soil?

  They have roots
• How does planting trees amongst crops protect them?

  They provide shade to reduce evaporation rates
• What is the effect of leaving areas of land to rest in between grazing?

  Lets them recover their nutrients
• How does crop rotation help prevent desertification?

  Prevents the same nutrients from being continually removed
• What does appropriate technology involve?

  Using cheap sustainable and easily available materials
• Besides providing shade, how else do growing trees amongst crops protect them?

  They act as windbreaks