Soils
Process of soil formation
Weathering and erosion
Humification
Leaching
Podzolisation
Laterisation
Salinisation
Calcification
Factors affecting soil formation
Climate
Parent Material
Topography
Soil Organisms
Time
Soil characteristics
Structure
Texture
pH value
Colour
Moisture
Organic matter
Irish brown earth soils
Texture
Humus content
pH
Colour
Soil Profile
Composition of soil
Mineral particles/matter
Organic matter
Air
Water
Human interaction- The Sahel
Climate
Population
Desertification
Overgrazing
Over-cropping
Deforestation
silt, sand, stones and clay
size of particles depend on parent rock
some are soluble and dissolve in water
supplies nitrogen and oxygen to the soil
helps plant growth as it contains dissolved minerals and nutrients that are absorbed by the plants roots
consists of the remains of plants and animals as well as living creatures
humus is rich in nutrients and fertilises the soil
binds the soil particles together