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| Fractal features of soil particles on sloping farmland under downslope tillage system with limited slopelength in the Three Gorges Reservoir Area |
| Wei Jie 1,2,Jin Huifang3,He Xiubin2,Bao Yuhai2,Zheng Hongli1 |
1. College of Geography and Tourism, Chongqing Normal University, 400047, Chongqing, China;
2. Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, 610041, Chengdu, China;
3. Oil Resources Department of Technology & Engineering College, Yangtze University, 434020, Jingzhou, Hubei, China |
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Abstract Forty eight topsoil (0 - 20 cm) samples were collected from four kinds of typical sloping farmlands with horizontal ditch (HD), terrace ridge and bank (TR), terrace hedgerow (TH), and none conservation measures (NC) in Zhongxian County of the Three Gorges Reservoir Area. The surface soil particles, their fractal characteristics and their relationship with each other were studied using fractal dimension. The results showed that there was low volume of clay particles (8.03% - 11.47%) while high volume of silty particles (62.39% - 83.24%) in all surface soils on the four kinds of sloping farmlands. The sandy particles in the topsoil on sloping farmlands with HD, TR and NC were 22.95% - 29.58%; however, it accounted for only 5.29% in the TH sloping farmland topsoils. The volume fractal dimension for the surface soil particles on the HD, TR, TH and NC farmlands was 2.579 - 2.708, 2.603 - 2.706, 2.581 - 2.701, 2.610 - 2.827, respectively. The mean volume fractal dimension ordered from high to low as TH (2.737), HD (2.674), TR (2.659) and NC (2.654). The fractal dimension for the four patterns had significant linear positive correlation with clay particles ( < 0.002 mm) volume percentage, and had significant linear negative relationship with silty particles (0.002 - 0.05 mm) volume percentage. However, the fractal dimension for the NC, HD and TR patterns was positively correlated to the sand particles ( > 0.05 mm) volume percentage, while there was no significant correlation between them for the TH pattern.
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Received: 07 October 2013
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