广东省不同母质发育土壤颗粒分布的分形维数特征

Fractal Dimension of Particle-Size Distribution for Soils Derived from Different Parent Materials in Guangdong Province

采集广东省主要成土母质（玄武岩、砂页岩、第四纪红土和花岗岩）发育的林地、耕地和园地土壤剖面各发生层土壤,测定了土壤颗粒组成、有机质、CEC等理化性质,探讨了不同母质发育土壤颗粒分布的分形维数特征及其与土壤理化性质的关系。结果表明,玄武岩、第四纪红土、花岗岩和砂页岩发育土壤分形维数变幅分别为2.923 9-2.981 2,2.858 8-2.937 7,2.769 3-2.923 1和2.544 6-2.885 6;玄武岩和第四纪红土发育土壤颗粒分布分形维数与砂页岩发育土壤存在显著差异。土壤颗粒分布的分形维数随土壤深度增加呈增大的趋势,相同母质发育土壤的深层土壤颗粒分布的分形维数接近一致。玄武岩和第四纪红土发育土壤颗粒分布的分形维数在不同深度土壤之间变幅较小,砂页岩和花岗岩发育土壤变幅较大。土壤颗粒分布的分形维数与砂粒含量呈极显负相关,与黏粒含量呈极显著正相关,与土壤全磷、速效钾、全铁、CEC、有机质、全氮、碱解氮呈极显著或显著正相关;土壤颗粒分布的分形维数可以作为表征土壤肥力状况指标。

Soil samples under different land uses,including woodland,cultivated dryland and orchard,were collected from profile horizons which derived from main parent materials（including basalt,sand-shale,Quaternary red soil and granite）in Guangdong Province,soil physico-chemical properties such as soil particle-size composition,organic matter,CEC,etc.were determined.The fractal dimension of particle-size distribution（PSD）for soils derived from different parent materials and its relationship with soil properties were studied.The results indicated that the range of fractal dimension of PSD for soils derived from basalt,Quaternary red soil,granite and sand-shale were 2.923 9to 2.981 2,2.858 8to 2.937 7,2.769 3to 2.923 1,and 2.544 6to2.885 6,respectively.The fractal dimension of PSD for soils derived from basalt,Quaternary red soil and sand-shale were significantly different.The fractal dimension of soil PSD showed an increasing trend with increasing soil depth,and the fractal dimension of soil PSD was almost the same in deep horizons of soils derived from the same parent material.The fractal dimension of soil PSD had smaller variation between soil at different depth in soil profiles derived from basalt and Quaternary red soil,however,the variation was larger for soils derived from sand-shale and granite.The fractal dimension of soil PSD was significantly negatively correlated with sand content,but was significantly positively correlated with clay content,soil total P,available K,total Fe,CEC,soil organic matter,total N,available N.The fractal dimension of soil PSD could be applied as a quantitative index reflecting soil fertility.