Characterization and Distribution of Clay Minerals in Corn Field Soils in Korea

Distribution of clay minerals separated from clay fraction of corn fields in Korea has been investigated along with their characterization. Crystalline phases of the clay minerals were identified by powder X-ray diffraction (XRD) pattern, and their relative chemical compositions were analyzed by X-ray fluorescence spectrometry (XRF). The soils were found to have pH 6.4, organic matter $37.2g\;kg^{-1}$, available $P_2O_5$ $599mg\;kg^{-1}$, respectively, and exchangeable K, Ca and Mg were 1.2, 7.3 and $1.8cmol_c\;kg^{-1}$, respectively. Major primary minerals consisted mainly of quartz and mica, and kaolinite and chlorite were identified as major secondary clay minerals. For most of soils, mica phase was identified to be muscovite rather than biotite. The average contents of $SiO_2$, $Al_2O_3$ and $Fe_2O_3$ were 43.7, 23.6 and 8.8%, respectively, although they were different with the locations.