Abstract: | Artificial weathering of silicate rock powders The weathering properties of rock powders of different geological origin were investigated under laboratory conditions. Extraction media were water and hydrochloric acid (1N). The parameters measured were pH-value and (under the point of view of plant nutrition) the macro elements Ca, Mg, K and Na as well as the trace elements Fe, Mn, Cu and Zn. Of the tested rocks, basalt, diabas, phonolite, lava and granite, the basic origins are characterized by a high release of Ca, Mg and Fe, phonolite by a noticeable release of Na, and lava by a significant mobility of K. Mn was extracted to greater extent than Cu and Zn. The price level of some rock powders is shown and discussed with special reference to the presented data of nutrient release. |