Soil is a layer of unconsolidated material at the surface of the earth which has been derived from rocks and organic matter through agencies of decay and disintegration.

Three horizons of soils are:
1. Top soils 
2. Sub soils 
3. Parent rock.

The common physical properties of soil are:

1. Texture,
2. colour,
3. effective depth,
4. structure,
5. permeability,
6. moisture- holding Capacity,
7. surface drainage,
8. slope and erosion.