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