Soils and Regolith
Pedology- The study of soils
SITE
FLUX
• Pedogenic processes depend on:
ClORPTH
–
–
–
–
–
–
Climate - Temperature, H2O, freezing
Organisms - Addition and digestion of Org. Material
Relief - Slope Steepness - Balance with erosion
Parent Material - what do you start with?
Time - How long has it been sitting there?
Humans - Addition of fertilizer, tillage, salinization, etc…
The importance of soils
• Life on Earth
depends on soil
• Soil is a vital nonrenewable
resource
– It takes > 1000’s of
years to form a soil
• Chemical
weathering
happens in soils
Soil Degradation (erosion)
The Dust Bowl
Soil Horizons
E/A2
Soil Formation
Clay
Formation in
Soils
Primary
2:1
1:1
0:1
Some Soil Profiles
Oxisol
Alfisol
Aridisol
Soil Water
Climate and Organisms
Relief
Parent Material
Time
Naming Soils
Soils are named on the basis
of Subsurface horizons
•Layers in the soil that
reflect soil forming
processes
Soil Orders
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Alfisols - Moderate temperature forests
Andisols - Soils on volcanic material
Aridisols - Soils from deserts
Entisols - Little soil formation
Gelisols - Soils in cold regions w/ permafrost
Histisols - Soils on peat
Inceptisols - Young soils
Mollisols - Grassland soils
Oxisols - Tropical forests
Spodosols - Cool, wet coniferous forests
Ultisols - Tropical and subtropical forests
Vertisols - Soils with cracks
Global Soil Distribution
Major Terrestrial Biomes