Pedosphere 15(6): 739--745, 2005
ISSN 1002-0160/CN 32-1315/P
©2005 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Soil strength characteristics along an arable eroded slope |
PENG Xin-Hua1 , ZHANG Bin1, ZHAO Qi-Guo1 and R. HORN2 |
1 State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China).E-mail: xhpeng72@yahoo.com.cn
2 Institute of Plant Nutrition and Soil Science, CAU Kiel, Olshausenstr, 40 D-24118 Kiel (Germany) |
| ABSTRACT |
| Undisturbed soil cores were taken from different slope positions (upslope, backslope and footslope) and soil depths (0-15, 20-35 and 100-115 cm) in a soil catena derived from Quaternary red clay to determine the spatial changes in soil strength along the eroded slope and to evaluate an indicator to determine soil strength during compaction. Precompression stress, as an indicator of soil strength, significantly increased from topsoil layer to subsoil layer (P < 0.05) and was affected by slope position. In the subsoil layer (20-35 cm), the precompression stress at the footslope position was significantly greater than at the backslope and upslope positions (P < 0.05), while there were no significant differences at 0-15 and 100-115 cm. Precompression stress followed the spatial variation of soil clay content with soil depth and had a significant linear relationship with soil porosity (r2 = 0.40, P < 0.01). Also, soil cohesion increased with increasing soil clay content. The precompression stress was significantly related to the applied stress corresponding to the highest change of pore water pressure (r2 = 0.69, P < 0.01). These results suggested that soil strength induced by soil erosion and soil management varied spatially along the slope and the maximum change in pore water pressure during compaction could be an easy indicator to describe soil strength. |
| Key Words: pore water pressure, precompression stress, soil erosion, soil strength |
| Citation: Peng, X. H., Zhang, B., Zhao, Q. G. and Horn, R. 2005. Soil strength characteristics along an arable eroded slope. Pedosphere. 15(6): 739-745. |
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