Soil Reactions

1
Soil Reactions

• Acidity and Alkalinity

2
Acidity and Alkalinity

• What is pH?
• What is cation exchange capacity?
• What are the applications in soil?

3
Household pH Scale
How To Build Your Own pH Scale 1. Using cooked
red cabbage juice fill each beaker to 50ml. 2.
Then place one compound in each beaker, seven in
all. 3. Carefully record each color change as it
occurs. 4. Next determine which color is Acid or
Alkaline. 5. Now you have your own pH scale. Lab
is due at the end of the Hour
4
pH Scale
Range of Acidity
Range of Alkalinity
neutral
1 2 3 4 5 6 7 8 9
10 11 12 13 14
Phosphoric Acid
Distilled Water
Lye
Blood
Milk
Tomatoes Lemons Vinegar
Ammonia
Milk of Magnesia
5
Ion exchange of soil particles

• Figure 1
• Mineral nutrients held on the surface of a soil
  particle are absorbed

6
Ion Exchange Of Soil Particles

• Figure 2
• A soil particle with mostly hydrogen ions test
• Acid

7
Ion Exchange Of Soil Particles

• Figure 3
• A soil particle with mostly basic ions tests
• Alkaline