1. Review Soil is a mixture of 4 materials:
Weathered rock particles (sand, silt, and clay)
Organic matter
Water
Air

2. Review

3. Horizon O - organic-mostly dead plant matter.
Horizon A - Topsoil. Contains the most organic matter (humus) and is dark in color.
Horizon B - Subsoil. The layer under A that contains clay and minerals and is usually brownish or reddish in color.
Horizon C - Parent material. The deepest layer of soil. Contains the largest and least weathered rocks. It is usually yellow-brown.
Horizon D – Bedrock below soil.

4. Add To Table of Contents:
Soil Worksheet Pg. 70
Soil Properties Pg. 71

5. Soil Properties Pg. 71

6. 1. Porosity - amount of space between sediments.
A. Shape-Rounded particles have greater porosity than angular.
POROSITY
ROUNDNESS
ROUND
ANGULAR

7. B. PACKING- The closer the particles the lower the porosity.
UNPACKED
PACKED

8. C. SORTING-The more sorted the higher the porosity.
- Same size=sorted.
- Different sizes = unsorted (poorly sorted)
POROSITY
SORTING

9. Particle Size alone does NOT affect porosity
Particle Size alone does NOT affect porosity!!!!! (Shaping, Packing, Sorting does)

10. 1 2 3 4 1

11. 1 2 3 4 1

12. 2. Permeability-ability of water to pass through
-Tighter packing/smaller particles = less
-Looser packing/larger particles = more
PERMEABILITY
PARTICLE
SIZE

13. Impermeability(not permeable) is due to:
A. Tight packing of particles
B. Cementing by clay or ice

14. FINE SAND Moderate drainage
PERMEABILITY
GRAVEL  Rapid drainage
 FINE SAND Moderate drainage
 CLAY Slow drainage

15. 1 2 3 4

16. Clay is impermeable – water will not flow through easily

17. 3.Capillarity-water sticking to soil particles and moving up from the water table. (capillary action).
- Smaller particles have more
capillarity.
CAPILLARITY
PARTICLE
SIZE

18. 4. Infiltration – water soaking into the ground.
Permeability
Infiltration rate
Porosity
Infiltration rate
Infiltration rate
Slope