1. Soil
The following power point was adapted from Ryan P. Murphy. A full collection of his amazing power points can be found at:

2. SOIL

3. Weathering is the process that will, overtime, create soil.

4. Soil is a mixture of weathered rock and decaying organic material.

5. Soil Formation
Soil is formed as rock is broken down by weathering and is mixed with other materials on the surface by burrowing animals.
Soil is constantly being formed wherever bedrock is exposed.
Bedrock is the solid layer of rock beneath the soil.

6. Five Factors That Affect Soil Formation
Climate: temperature and rainfall
Plants and animals
Topography: flat lands are more fertile than hilly lands
Parent material
Time: more time = healthier soil

7. Four Steps To Soil Formation
Bedrock disintegrates

8. Four Steps To Soil Formation
Bedrock disintegrates
Parent material forms

9. Four Steps To Soil Formation
Bedrock disintegrates
Parent material forms
Organic matter collects forming humus

10. Four Steps To Soil Formation
Bedrock disintegrates
Parent material forms
Organic matter collects
Thick vegetation grows and gives back to the soil

11. Soil Composition
Soil is a mixture of rock particles, minerals, decayed organic material, air, and water.
The type of rock particles and minerals depends on the bedrock that was weathered and the type of weathering.
Sand, Silt, and clay make up the portion of soil that comes from weathered rock.

12. Humus Decayed, organic material in soil Dark in color
Forms from decaying plant and animal material
Creates spaces in soil for air and water
Rich in nutrients that plants need to grow

13. Color Of Soil- helps determine what soil is made of and its health

14. Black Soil Lots of organic matter (carbon) May be poorly drained
Usually fertile

15. Brown Soil
Lots of sand and clay
Well drained
Good soil

16. Light brown, white, orange, red, yellow
Many compounds present (iron, manganese, sulfur)
High is salt
Not as healthy
Iron turn rust color when it mixes with oxygen (oxidation)

17. Particles of Soil The type of soil depends on its particles
The combinations of particle size can determine how well plants grow in soil

18. Soil Texture and Particle Size
Gravel: 2-7.5cm

19. Soil Texture and Particle Size
Gravel: 2-7.5cm
Sand: mm

20. Soil Texture and Particle Size
Gravel: 2-7.5cm
Sand: mm
Silt

21. Soil Texture and Particle Size
Gravel: 2-7.5cm
Sand: mm
Silt
Clay

22. Soil Horizons
Soil Horizon is a layer of soil that differs in color and texture from the layers above or below it.

23. O – organic layer (leaves, pine needles, twigs, decay)
A – Top Soil: dark color is from the mixing of humus with weathered materials
E – Eluviated zone; movement of dissolved materials from A horizon
B – Sub Soil; Illuviated zone – contains soil materials leeched from above
C – Parent Material; partially weathered mineral particles
D/R - Bedrock

24. Rate of Soil Formation Depends on climate and type of rock
Weathering occurs most rapidly in a warm, rainy, climate
Some rocks, like limestone, weather faster than other types of rock, like granite.