Andic Properties of Major Soils in Cheju Island II. Electric Charge Characteristics

제주도(濟州島) 대표토양(代表土壤)의 Andic 특성(特性)에 관한 연구 II.전하특성(電荷特性)

  • Published : 1991.12.30


Electric charge characteristics of volcanic ash soils in Cheju Island were investigated. For this study, soils of toposequence distributed along the sourthern slope of Mt. Halla, and the major soil groups such as dark brown soils, very dark brown soils, black soils, and brown forest soils were collected and analyzed for extratable acidity, KCl ext. Al, CEC, base saturation, permanent charge and variable charge, etc.. Weolpyeong and Yongheung soils developed on the lower elevations have high $NH_4OAc$ ext. bases, permanent charge and base saturation, and relatively low ext. acidity, CEC and variable charge. For other soils, whose colloidal fractions are dominated by allophane or Al-humus complexes, ext. acidity, CEC, variable charge, and variable charge ratio were very high, and $NH_4OAc$ ext. bases, permanent charge, and base saturation were very low. These trends were especially prominant in the surface. horizons of black soils and brown forest soils dominated by Al-humus complexes. Ext. acidity, CEC($NH_4OAc$), CEC(sum of cations), and variable charge strongly correlated with pyrophosphate ext. carbon. Very dark brown soils and cinder cone soils dominated by allophane showed low KCl ext. Al and relatively high pH, despite their very low base saturation.