Research Progress and Prospect of Mechanical Effects and Model Construction of Root-soil Complex

[Objective] In order to investigate the mechanism of mechanical effect of root-soil complex and the application of modeling method. [Methods] The concept and connotation of root-soil complex, the principle of mechanical effect and mechanical model of root-soil complex, advantages and disadvantages as well as the scope of application were summarized and analyzed by using literature analysis method and comparative analysis method. [Results] (1) The root-soil complex was a composite whole of mechanical coupling effect between root system and soil body, and the root system was intertwined in soil playing a reinforced role. (2) The mechanical relationship between root system and soil body was essentially the result of soil mechanical, hydraulic and composite mechanical properties of root-soil complex. The soil mechanical and hydraulic properties focused on the influence of roots on the soil and the influence of water on the soil and root system respectively, and the composite mechanical properties focused on the direct influence of soil properties on the properties and structure of plant roots, so that the mechanical relationship between roots and soil was in a dynamic balance through the three. (3) The study of the composite mechanical model of the root-soil complex was slightly less than that of the soil mechanical and hydraulic model, which were based on quantitative parameters and measure the soil consolidation effect by comparing parameters. However, the composite mechanical properties involves both soil and hydraulic properties, which was a comprehensive consideration and should be the key research direction in the future. [Conclusion] In-depth research was needed in the future to investigate the effects of freeze-thaw cycle, dry-wet alternation and dry-hot cycle on root and soil interaction in different regions, the shear strength of multi-type plant mixtures, the influence mechanism of chemical and microbial effects on soil-water propertiess and the construction of composite models need to be further studied. This study can provide important theoretical value and engineering reference for vegetation restoration, soil and water conservation and sustainable development in ecologically fragile areas.