10. Soils

• soil - the loose material that makes up the earth's surface
• make-up of soil

  • 4% humis
  • 1% living organisms
  • 25% water
  • 25% air
  • 45% parent rock
• parent rock - the rock which the sediment in the soil is made from
• humis - jelly substance rich in nutrients, made of remains of plants
• water - dissolves minerals and nutrients
• air - essential for plant growth
• living organisms - mixes soil and allows air and water to pass
• human activity - if overused soil will no longer be fertile
• granite takes longer than limestone to make soil
• conoferous trees can starve the soil of nutrients and can form a hardpan layer
• hardpan layer - a hard, compacted layer of soil that is resistant to erosion
• types of soil

  • peat soil (bogs)
  • grey (waterlogged)
  • brown earths
  • podzols