Non-exchangeable and exchangeable potassium status of soils in relation toclay mineralogy and other soil properties in Hilvan area of upper Mesopotamia in southeastern Anatolia

Non-exchangeable and exchangeable potassium (K) contents in relation to cla y mineralogy of the 105 soil samples collected from 35 soil series in the H ilvan area of the upper Mesopotamia in the southeastern Anatolia were studi ed. It was concluded that the major part of the non-exchangeable K is locat ed in the clay fraction which is predominantly of smectite, with some kaoli nite and a small amount of paligorskite. In addition, a strong positive cor relation between the non-exchangeable and exchangeable K fraction indicated that as the non-exchangeable K increases, the amount of exchangeable K als o increases, resulting in higher buffering capacity of soils in terms of K than that of soils low in non-exchangeable K.