1. Discuss the soil profile for surface and subsurface layers
Objective 5.02
Discuss the soil profile for surface and subsurface layers

2. What is the physical make up of soil?

3. Soil Profile Layers of soil are called horizons Typical profile
A Horizon-topsoil
most fertile
most organic matter
top or first layer
B Horizon-subsoil
C Horizon-bedrock

4. Soil Profile

5. Soil Structure How particles cluster together single grain
granular (best for most plants)
blocky
platy
massive

6. Soil Structure
Single Grain

7. Soil Structure
Granular

8. Soil Structure
Blocky

9. Soil Structure
Platy

10. Soil Structure
Massive

11. Soil Structure
Soil structure is more important to producers who grow plants in natural soils
Examples: tobacco farmer, vegetable gardener
Producers of container grown plants add ingredients to make growing media desirable and are not as concerned with the natural soil’s quality
Example: A greenhouse grower uses potting soil instead of “natural” soil.

12. Soil Texture
Size of particles
Types of textures
clayey
loamy
sandy

13. Clayey Texture Small particles Has a high water-holding capacity
most common texture in western NC

14. Loamy texture About equal parts of sand, clay and silt
Ideal texture for most non-container outside plants

15. Sandy texture Large particles Low moisture-holding capacity
Most common in eastern NC

16. Which has largest soil particles, Sand or Clay?

17. Soil pH Measurement of acidity or alkalinity from 0 to 14
Acid-less than 0-6.9
Alkaline-more than 8-14
Most organic matter is acid
Most artificial media is neutral
Ideal pH for most gardens is 5.5 to 7.0

18. Terms to know about Physical Properties of Soils
Permeability
rate at which water moves through the soil
Water holding capacity
ability of a soil to hold water for plant use
Porosity
amount of air space between soil particles

19. Physical Properties of Soils
50% of soil should be pore space
25% water space
25% air space.
50% of soil should be soil particles
45% mineral matter
5% organic matter
WHY DO PLANTS NEED PORE SPACE IN THE SOIL? OXYGEN FOR ROOTS!

20. The ideal soil is 50% solid particles, 50% pore space. Soil Makeup
Water
The ideal soil is 50%
solid particles,
50% pore space.