Unformatted text preview: NRES 201 Intro to Soil Science Lec. 33 4/9/2009
Potassium and Micronutrients Ch. 13 POTASSIUM K is a common eleruent. the lithosphere contains
~ 2 6 ' Felsic rocks. rich in aluminosilicate minerals (mica.
feldspar). contain high amount of potassium
(granite, schist. gneiss). Mafic rocks. rich in iron and magnesium minerals,
contain 10“ amounts of potassium (gabbro, basalt). POTASSIUM Sedimentary rocks contain Variable amounts of K.
Shales ~27 g K/lgg
Sandstones ~11 g K/lgg Liruestones ~3 g K/lgg Soils contain [101110.04 to 3 K. the low er amounts
01K in soils reﬂects the loss 01K during \y eathering and soilfor‘11121tior1. POTASSIUM 1 to 10 I the potassium in soil occurs as fixed cations
in the interlayer of Vermiculites and possibly some
highly charged smectites. 1 to of the total potassium in soil occurs as K’ ions
in the soil solution and 011 the exchange complex. The most important source of potassium in soils are the
micaceous minerals and their \y eathering products. ...
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- Spring '08