Soil

Soil

1. Influences on formation

   • Living organisms
   • Landscape
   • Vegetation
   • Time
   • Parent material
   • Climate

2. Composition

   • 43% mineral matter
   • 25% air
   • 25% water
   • 5% humus
   • 2% living organisms

3. Leaching

   • Causes hardpan

4. Profile

   • A horizon
     • Topsoil
   • B horizon
     • Subsoil
   • O horizon
     • Plant litter
   • C horizon
     • Bedrock/parent material

5. Human interference

   • Soil erosion
     • Overcropping
     • Deforestation
     • Overgrazing

6. Characteristics affecting vegetation

   • Fertility
   • Acidity
   • Depth
   • Drainage

7. International soils

   • Tropical red soils

8. Irish soils

   • Brown earth
   • Podzols
   • Gley
   • Peaty