1. Soil Mineralogy and Potassium Availability

In this talk, I will try to answer four questions. The outline below gives the overall framework for the presentation. 1. What are the mineral sources of potassium? Primary minerals crystallize from the magma. Those that contain K are: Feldspars (microcline and orthoclase)  Micas (biotite and muscovite) Primary minerals weather  decompose  by several mechanisms. Chemical bonds are destabilized by acid attack. Al ions are complexed by organic... M.L. Thompson