1. Formation of Soil
SWBAT describe how soil forms; explain the relationship between the organic and inorganic components of soil; identify soil characteristics; recognize soil horizons in a soil profile

2. Development of Soil Soil Describe the process of soil formation
The loose covering of broken rock particles and decaying organic matter
Describe the process of soil formation
Weathering breaks solid bedrock into smaller pieces
These pieces continue to break down
Organisms, such as bacteria, fungi, and insects begin to live in the weathered material
The organisms die in time, decay, and support a variety of life forms
There is a continual process of break down creating nutrients and texture, as well as the ability to hold water (porosity)

3. Soil Composition Residual soil Transported soil
Soil located above its parent material (the rock it was weathered from)
Transported soil
Soil that has been moved away from its parent bedrock by erosion

4. Soil Profiles Soil profile Soil horizon
The vertical sequence of soil layers
Soil horizon
A distinct layer or zone within a soil profile
Generally 3 distinct horizons
Horizon A has concentrated organic matter and humus (top)
Horizon B contains subsoils enriched with clay (middle)
Horizon C contains contain weathered parent material (bottom)

5. Topography How does topography affect soil?
Affects the thickness of soil
In sloped areas, coarser material remains on the slope, while finer particles are pulled downslope due to gravity
Soils on slopes tend to be infertile, where lower areas are thick and fertile
Direction of the sun also plays a role in soils fertility

6. Soil Types Polar Temperate Desert Tropical
Form at high latitudes. Soils have good drainage but no distinct horizons because they are very shallow due to permafrost
Polar
Temperate
Desert
Tropical
Able to support diverse environments, such as forests, grasslands, and prairies. They get approximately cm of rainfall a year.
Receive low levels of precipitation which creates soil that few plants can survive in and weathers easily.
These areas experience high temperatures and heavy rainfalls creating highly weathered and infertile soil

7. Soil Texture and Fertility
What are the three classifications for the size of soil?
Clay < mm
Silt mm
Sand 0.05 – 2 mm
What is soil fertility?
The measure of how well a soil can support the growth of plants
What factors determine a soils color?
Its composition and the climate

8. Get your lab notebook
In your groups, complete the problem solving lab on page 172.