Soil Activity
Soil Colloids: Charged, chemically active
particles of soil
- Very small (< 1 micrometer)
- Large surface area for elements to attach to
Soil Colloids constantly exchange elements with the solution to transfer nutrients to the root hairs of plants...
...the ability of the soil colloid to transfer elements into the solutions is dependent upon the Cation Exchange Capacity
Cation Exchange Capacity: The measure of how many nutrients a soil can provide to plants
Characteristics of Low CEC
- Few charged spaces available with weak bonds for elements to attach to
- High sand content
- Higher fluctuations in pH
Characteristics of High CEC
- Many negatively charged spaces with strong bonds elements to attach to
- High clay and organic matter content
- Resistant to pH change
Low CEC
High CEC
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As pH increases, more positively charged, hydrogen ions are released from the soil colloid into the solution - this causes there to be more negatively charged spaces on soil colloids to attract positively charged nutrients like Potassium, Calcium, and Magnesium.