Quantitative analysis of soil anti-shearing strength enhancement by the root systems of herb plants

Authors ZHAO LiBing; ZHANG BaoGui; SU ZhiZhu

Journal Chinese Journal of Eco-Agriculture , 2008,3:16

Abstract Shallow soil anti-shearing strength enhancement was verified and quantified in the Loess hill gully area of Zhuanyaogou watershed, Hequ County, Shanxi Province, through in-situ direct shear-strength test and modeling of 4 representative herb plants. In 0 -20 cm soil layer, there is a considerable effect of herb plant root system on soil anti-shearing strength. Soil anti-shearing intensity （ 15.33 kPa） by Medicago sativa is highest. Particularly in the 20 -40 cm soil layer, Melilotus officinalis and M. sativa can drastically enhance soil anti-shearing strength. Meanwhile analysis of the difference between model prediction and field observed values for soil anti-shearing strength enhancement by plant shows the true value to be between the two. The research shows that the 4 herb plants root systems own strong tensile strength and has negative correlation with the root diameter. The research has significant implication in forecasting and the appraising soil reinforcement by herb root system in loess regions. With regard to the choice and optimal organization of soil and water conserving plants, the research may provide a theoretical guidance on potential soil reinforcement capacity by plant root system.

Species covered 紫苜蓿 Medicago sativa 草木犀 Melilotus officinalis