1. Add To Table of Contents:
Soil Lab Pg. 50
Soil Properties Pg. 51

2. Review

3. Review-What are the Soil Horizons?
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 - The deepest layer of soil. Contains the largest and least weathered rocks. It is usually yellow-brown.
Horizon D – Bedrock below soil.

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

5. Soil Properties Pg. 51

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. Which column has the least porosity?1 2 3 4 1

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

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

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

14. Which has the least permeability?1 2 3 4

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

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

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

19. Honors Lab Activity