喀斯特山区不同母质(岩)发育的土壤主要理化性质差异性分析

Changes of Soil Physical-chemical Properties Derived from Different Parent Materials/Rocks in Karst Mountain

在贵阳市乌当区采集了白云岩、石灰岩、钙质紫色砂页岩等9种母质(岩)上发育的土壤样品763个,分别进行了土壤主要理化性质的测定和差异性分析。结果表明不同母质(岩)发育的土壤理化性质具有很大的差异:红色粘土、老风化壳和页岩上发育的土壤pH值均为酸性至强酸性,有机质和CEC含量中等,土壤质地较粘重;石灰岩、白云岩和钙质紫色砂页岩上发育的土壤pH值为中性至微碱性,有机质和CEC含量较高,质地较为适中;砂页岩和河流冲积物上发育的土壤pH值为酸性至中性,其余理化性质为中等水平;砂岩发育的土壤pH值为强酸性,其余理化性质均较差。

After collection of 763 soil samples developed from 9 types of parent material/rock, i.e. dolomite, limestone, calcareous purple sandy shale, shale, sandstone, red clay, old mantle rock, fluvial sediment and sandy shale, from Wudang county of Guiyang city in Guizhou province, where the karst feature is well developed, physical-chemical properties of these soils were analyzed. Huge differences between the soils were found through comparing the soils developed from different types of parent material/rock. The differentiae in physical-chemical properties of these soils manifest that： soil textures developed from limestone, red clay, old mantle rock and shale are heavy; soil texture developed from sandstone is light. The pH of the soils developed from limestone, calcareous purple sandy shale and dolomite is neutral or mild alkaline; the pH of the soils developed from fluvial sediment is neutral; and the pH of the soils developed from other types of parent material/rock is acidic. The soils developed from calcareous purple sandy shale, dolomite and the fluvial sediment have more organic matter, however, organic matter content in the soil developed from sandstone is lower. CEC in the soils developed from fluvial sediment, limestone, dolomite and calcareous purple sandy shale is higher; but CEC in the soils developed from sandstone is lower.