西南典型水耕人为土诊断层黏土矿物特征

Clay Mineral Composition of Diagnostic Horizons in Stagnic Anthrosols: Implications for Soil Taxonomic Classification

选择我国西南地区代表性水耕人为土剖面,对其主要诊断层黏土矿物组成特征进行研究。采用沉降吸管法提取土壤黏粒,将其进行Mg2+饱和、Mg2+饱和加甘油处理、K+饱和加热550℃三种处理后,分别在X-射线衍射仪扫描,对所获图谱进行黏土矿物组成鉴定。实验结果显示西南地区代表性水耕人为土其诊断层黏粒黏土矿物组成特征主要为蛭石,高岭石,伊利石,混层矿物等。含少量其它黏土矿物如三水铝石,蒙脱石等。与旱地土壤比较,水耕人为土的黏土矿物组成有明显的不同。不同发育时间和水耕熟化的水耕人为土,其黏土矿物组成和数量上也有明显差异,研究结果对黏土矿物在水耕人为土系统分类上的应用具有一定的理论意义。

Clay mineral compositions of diagnostic horizons in Stagnic Anthrosols at different developmental levels in southwestern China were compared. The clay sedimentations were extracted by pipette method in three treatments, including Mg2+saturation, Mg2+saturation plus glycerol, and K+saturation plus 550 ℃ heating. The clay composition was investigated by X-ray scanning. Results showed that the main clay mineral compositions of Stagnic Anthrosols were vermiculite, kaolinite, illite and mixmineral etc. as well as other minerals such as gibbsite and smectite. Compared to dry land, the clay compositions of Stagnic Anthrosols were different distinctly. Also, the clay mineral compositions in diagnostic horizons of Stagnic Anthrosols at different development and paddy management levels were different obviously. These results have certain theoretical significance for the application of Stagnic Anthrosols classification.