Cation Exchange Capacity (CEC)
Curtis E. Swift, Ph.D.
Colorado State University Extension
Area Extension Agent (Horticulture)
The clay and organic components of the soil have a negative charge. As a result of these charges, positively charged ions (cations) such as hydrogen H+, potassium K+, ammonium NH+4, calcium Ca2+, magnesium Mg2+, aluminum Al3+, etc. may be held at the surface of the clay or organic particles and exchanged with other ions in the solution or with ions at the plant root's surface.
The ability of a soil to hold cations is termed its cation exchange capacity (CEC). Since many cations are plant nutrients the cation exchange capacity is a measure of the soil's ability to hold such nutrients.
Placed on the Internet December 14, 1999; Updated Dec 12, 2009
- Gardening and Horticulture Home Page
- Swift's Gardening Blog
-
- Follow @CurtisSwift
- The Arboretum
- Climate Information
- Definitions
- Donate to the Ute Learning Garden
- Flowers
- Fruit
- Garden Clubs, Societies and Botanical Gardens
- Hardiness Zone Maps
- Hops Production
- Houseplants
- Landscape Professionals
- Lavender Project
- Master Gardener Program
- Mulch
- Native Plant Master Program
- Pest Management and Pesticides
- Soil
- Trees and Shrubs
- Turf
- Ute Ethnobotany Learning Garden
- Vegetables
- Weeds
- CSU Extension
- Search CSU
- Ask an Expert
- The weather Grand Junction, CO