耕层土壤颗粒表面的分形特征研究

Fractal Dimensions of Soil Particle Surface in Plowed Layers

通过对31个土壤样品的测定，研究了不同质地耕层土壤颗粒表面的分形维数（D），结果表明D介于2．7060～2．9968之间，并且同一质地类型的土壤分形维数D差异不大，但有随土壤质地由紧砂土、砂壤土、轻壤土、中壤土、重壤土到轻粘土，分形维数D呈递增趋势。统计分析结果表明：土壤颗粒表面的分形维数D与10个粒级颗粒含量之间存在极显著的线性回归关系；4个粒级对分形维数D的直接贡献由大到小依次为：粘粒〉细粉〉粗粉〉中粉，无论哪一个粒级的颗粒含量增加，通过其它三个粒级的颗粒含量的间接效应都将使分形维数D增大；土壤有机质、土壤阳离子交换量分别与D有极显著正相关，可以用OM=-229．1113＋86．5400D和CEC=-84．6456＋32．1086D的直线回归方程来描述它们间的数量关系。

The fractal dimensions （D） of soil particle surface were studied by determining 31 soil samples from plowed layers with different texture. The results indicated that the D value was 2. 7060 to 2. 9968 in those soils, and the difference was not significant in the soils with the same soil texture, but the D value increased with the soil particle size from sand to clay. The statistical analysis results showed that： there was a linear regression relationship between the fractal dimensions of particle surface and soil particle contents. The importance of direct contribution of four smallest soil particle size to D value was clay 〉 fine silt 〉 coarse silt 〉 medium silt, and the increase of any kind of soil partial size content would result in the increase of D value by the indirect change of other soil particle contents. The relationship between the soil organic matter, CEC value and D value was positively correlated, and the correlation between soil organic matter content and D value could be described as O. M = -229. 1113 ＋86.5400D and CEC = -84.6456 ＋ 32. 1086D.