渭北旱塬区典型农业耕作土壤微形态分形研究

Micromorphological Fractal Features of Cultivated Soil in the Northern Weihe Area

利用分形几何的方法,对渭北旱塬典型旱作农业土壤微形态的分形特征进行了研究。在对土壤薄片详细观察的基础上,以土壤微形态数字图像为基础,利用SISCIAS V8.0软件提取了土壤孔隙与粗颗粒的有关参数,并用计盒维数法计算了其分形维数。结果表明,土壤孔隙分形维数与孔隙率、孔隙面积和周长呈现较好的相关性(依次为0.77874,0.68558,0.81487),粗颗粒分形维数与粗颗粒的含量、面积和周长也呈现较好的相关性(相关系数依次为0.98418,0.98406,0.93010)。说明了利用土壤微形态获得的土壤分形维数能够反映土壤结构的空间分布和变异规律,也反映了农业耕作活动对土壤的影响。

The micromorphological fractal features of cultivated soil in the Northern Weihe area are studied using fractal geometry method. With the aid of polarizing microscope and SISC IAS V8.0 software, micro- morphological features of the cultivated soils are observed. Void and coarse grain features and the fractal di- mension of the cultivated soils are analyzed and calculated using the box-counting method. Results show that void fractal dimension has a good relativity with porosity, void area, and void perimeter, with the correlation coefficients being 0. 778 74, 0. 685 58, and 0. 814 87, respectively. Coarse grain fractal dimension takes on a good relativity with area ratio, coarse grain area, and coarse grain perimeter, with the correlation coefficients being 0. 984 18, 0. 984 06, and 0. 930 10, respectively. The fractal dimensions of soil micromorphology are able to indicate the distribution characteristics of soil structure and the influences of human cultivation.