首页|Untangling the influence of soil moisture on root pullout property of alfafa plant

Untangling the influence of soil moisture on root pullout property of alfafa plant

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Root pullout property of plants was of key importance to the soil reinforcement and the improvement of slope stability. To investigate the influence of soil moisture on root pullout resistance and failure modes in soil reinforcement process, we conducted pullout tests on alfalfa (Medicago sativa L.) roots at five levels (40, 30, 20, 10 and 6 kPa) of soil matric suction, corresponding to respectively 7.84%, 9.66%, 13.02%, 19.35% and 27.06% gravimetric soil moisture contents. Results showed that the maximal root pullout force of M. sativa decreased in a power function with increasing soil moisture content from 7.84% to 27.06%. Root slippage rate increased and breakage rate decreased with increasing soil moisture content. At 9.66% soil moisture content, root slippage rate and breakage rate was 56.41% and 43.58%, respectively. The threshold value of soil moisture content was about 9.00% for alfalfa roots in the loess soil. The maximal pullout force of M. sativa increased with root diameter in a power function. The threshold value of root diameter was 1.15 mm, because root slipping force was greater than root breaking force when diameter >1.15 mm, while diameter ≤1.15 mm, root slipping force tended to be less than root breaking force. No significant difference in pullout forces was observed between slipping roots and breaking roots when they had similar diameters. More easily obtained root tensile force (strength) is suggested to be used in root reinforcement models under the condition that the effect of root diameter is excluded as the pullout force of breaking roots measured in pullout tests is similar to the root tensile force obtained by tensile tests.

shallow landslidesroot reinforcementsoil moisture contentthreshold of root diameterroot pullout forcesoil conservation

ZHANG Chaobo、LIU Yating、LIU Pengchong、JIANG Jing、YANG Qihong

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College of Water Resources Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China

Changjiang River Scientific Research Institute, Changjiang Water Resources Commission, Wuhan 430010, China

This study was funded by the National Natural Science Foundation of ChinaNatural Science Foundation of Shanxi Province of ChinaProgram for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi Province of ChinaScientific and Technological Innovation Programs of Higher Education Institutions of Shanxi Province,ChinaNational Key Research and Development Program of China

31600582201701D22122420172019L01752018YFC0407803

2020

干旱区科学
中国科学院新疆生态与地理研究所,科学出版社

干旱区科学

CSTPCDCSCDSCI
影响因子:1.743
ISSN:1674-6767
年,卷(期):2020.12(4)
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