Potassium Fixation by Phyllosilicate Clay Minerals
Fragment of a discussion from Course talk:APBI200
Potassium fixation is analogous to ammonium (NH4) fixation: the process amounts to “lock up” K ions in the interlayer spacings of 2:1 phyllosilicates. Weathering at the crystal edge can make fixed K available, but this release can occur only slowly. A significant portion of applied K-fertilizer may become fixed and therefore made unavailable in soils containing abundance of these type of 2:1 minerals (called fine-grain mica or ilite).