SOIL

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SOIL
Rendzina soil, White Horse Hill, Berkshire Downs
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What is a soil?

• Collins English Dictionary defines soil as, the
  top layer of the land surface of the earth that
  is composed of disintegrated rock particles,
  humus, water, and air.

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Soil Functions

• Plant water supply
• Plant nutrient supply
• Aeration
• Support

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UK Soil Classification
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Agricultural soil problems

• Salinization- particularly in areas with
  irrigation agriculture. Not a new problem (e.g.
  Mesopotamia)
• Erosion- problems are caused by two major
  agencies, wind and water. It is estimated that
  agricultural topsoil is now being lost between 16
  and 300 times faster than it can be replaced.
  Processes responsible for soil formation are very
  slow, requiring 200 to 1,000 years to form 2.5 cm
  of topsoil.

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Industrial soil problems

• Contaminated land- approximately 100,000
  contaminated sites in the UK
• Acid rain and soil acidity- results mostly from
  the burning of sulphur-rich fossil fuels to
  produce sulphur dioxide, and during the process
  of combustion by oxidation of nitrogen present in
  the air to form nitrogen oxides.

Parys Mountain, Anglesey