Skyllberg, Ulf
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
Abstract
In soils with a neutral reaction, the metal cations calcium, magnesium, potassium and sodium are electrostatically attracted to soil particles, described as an electric double layer (EDL) of positively charged cations and negatively charged surfaces. In soils dominated by permanently charged clay minerals, cations in the EDL are rapidly and reversibly exchanged with cations in the bulk solution, as described by selectivity constants. In soils low in clay minerals, the major source of negative charge is soil organic matter and variably charged metal oxides. In acidic organic and forest soils, cation exchange between aluminum and hydrogen ions is an important pH buffering process.
Keywords
Acidity; Aluminum; Base cation; Base saturation; Calcium; Cation exchange capacity; Cations; Electric double layer; Hydrogen ion; Magnesium; Permanent charge; pH; Potassium; Selectivity constant; Sodium; Variable charge
Published in
Title: Encyclopedia of Soils in the Environment
Publisher: Elsevier
SLU Authors
UKÄ Subject classification
Soil Science
Publication identifier
- DOI: https://doi.org/10.1016/B978-0-12-822974-3.00063-X
- ISBN: 9780128229743
- eISBN: 9780323951333
Permanent link to this page (URI)
https://res.slu.se/id/publ/142826