关中地区不同耕作历史土壤的微形态特征及对比研究

Comparison to the Micromorphological Features of Cultivated Soil with Different Farming Time in Guanzhong Areas

用显微镜和Qwin软件对关中地区不同耕作历史土壤A和B的微形态进行了观察和定量分析.结果表明:耕作土壤具有Ap-(BC)-C构造;不同土壤粗颗粒主要由石英和长石组成,但不同矿物间的比例、颗粒形态、C/F(10μm)值等有明显差异.耕作历史和方式对矿物组合影响不明显,但对颗粒形态有显著的影响,耕作时间愈长,颗粒的长度、等圆直径、周长和面积减小和圆度增加愈明显。

Samples were collected from the A and B soil profile in Guanzhong areas to observe and quantitatively analyze their micromorphological features with the aid of a polarizing microscope and the LEICAL Qwin software. Micromorphological observations of the thin sections showed that the long-term cultivated soil had Ap-BC-C soil profile pattern and the short-term cultivated had Ap-（BC ）-C soil profile pattern. The minerals assemblage of different soil profiles and different horizons was very similar, which is mainly composed of Q and P1, but somewhat obvious different in C/F10um ratio, mineral content, and shape of particles. All the results of this study suggested that cultivated history distinctly affected the shape of particles. The longer was the cultivated history, the clearer was the decrease of length, area, Eq diameter, perimeter, roundness of coarse.