STUDY OF THE INTERLAYER POTASSIUM RELEASE OF SOIL MINERALS THROUGH KINETIC METHODS

In this paper, the kinetic methods used in studying the release of inter-layer K of soil minerals are grouped and commented on, and the rate of K-release and the affecting factors as well as the kinetic mechanisms are reviewed in more detail.The researchers’ results indicated that, small clays released interlayer K at a higher rate than larger ones, and so did the triotahedral (trio.)silicate minerals than the dioctahedral (dio.) ones.The rates of K-release of micas in releasing order were. Fe-rich biotite (trio.)Mg-rich phlogopite (trio.) muscuvite (dio.) .Their fraction of interlayer K released was a linear function of the square root of time.Martin’s experimental data suggested that the rate of K-release of soils employed could be discribed satisfactarily by the first-order diffusion equation.Hydrogen ion concentration up to 10-8 or higher (pH3) may lead to the distruction of the clay structure so as to speed up the rate of K-release. The relation between temperature (T) ,the rate of leaching (L) and the salt concentration (N) and the rate of K-release could be expressed as r = k(L. AT-N1/2) .During the release of potassium, several kinetic mechanisms were involved simultaneously, however, the interdiffusioa -was the most essential one.