1. Soil Science
Objectives: Identify the major soil areas of Alabama. Identify the layers in a soil profile.
Determine the texture of different soil samples. Determine the land capability class for a given plot of land. Discuss how to adjust pH.

2. Soil Profile OM- Organic Matter A- Topsoil B- Subsoil
C- Parent Material

3. OM Horizon OM- Organic Matter- 0-2 inches deep
Made of decomposed plant and animal material
Rich in nutrients
Improves soil structure
Increases soil water holding capacity
NOT ALWAYS PRESENT

4. A Horizon A Horizon- Topsoil- Up to 10 inches deep
Most important horizon for crop production
Must prevent the erosion of this horizon
It takes years to form 1 inch of topsoil

5. Topsoil

6. B Horizon
B Horizon- Subsoil- from topsoil up to 48 inches deep or more
There is usually a definite line between the topsoil and subsoil
Subsoil needs to be at least 36 inches deep to support the roots of crops.

7. Subsoil

8. C Horizon C Horizon- Parent Material- below the subsoil
The rock the soil came from
The parent material of a soil determines many of the soils characteristics

9. Parent Material and Bedrock
All horizons are clear
C horizon is the peach colored
Bedrock at the bottom is actually called the R horizon

10. Soil Texture
Sand
Silt
Clay

11. Sand Course texture, large particles Low water holding capacity
Drains too quickly

12. Sand

13. Silt Medium texture, medium particles Good water holding capacity
Good drainage

14. Silt

15. Clay Fine texture, small particles High water holding capacity
Drains too slow
Can be red or black

16. Clay

17. Soil
State Soil
of Alabama
Bama sandy loam
Mix is best

18. Primary Succession

19. Soil Areas of Alabama Coastal Plains Black land Prairie
Piedmont Plateau
Limestone Valleys
Appalachian Plateau

20. pH pH-stands for percent Hydrogen Defined as a measure of acidity
Scale is from 0-14, 7 is neutral

21. pH scale
0-6.9 is Acidic
is Alkaline
7 is neutral

22. pH pH determines nutrient availability for plants
If pH is too high or low the nutrients in the soil are not available to the plants

23. Soil Test Test in a zigzag pattern Test determines pH and fertility
15-20 samples in 20 acres

24. Correcting pH Lime raises pH if acidic Apply Lime if 5.7 or below
Sulfur lowers pH in alkaline soils