Biogeography and soils (physical side)
Soil formation and the soil profile
Practise 1 PYQConcepts to cover
- Soil-forming factors: parent material, climate, relief, organisms, time
- Soil profile: O, A, B, C horizons; leaching and illuviation
- Soil texture (sand, silt, clay) and structure
- Organic matter, humus and water-holding capacity
- Salinisation and alkalinity from irrigation and poor drainage
- Soil as a store of nutrients: nitrogen, phosphorus, potash, sulphur