Journal of Yangtze River Scientific Research Institute

   

Experimental study on a new spray-mixed vegetation substrate for ecological restoration of high and steep red soil slopes

XU Wen-sheng1,2,3, LIU Yao-song1,2, WANG Ke2,3, ZHANG Zhi-hua2,3, ZHANG Wen-jie2,3, LI Li2,3, XIAO Hai1   

  1. 1. College of Civil Engineering and Architecture, Three Gorges University, Yichang 443002, China;
    2. Changjiang River Scientific Research Institute, Wuhan 430010, China;
    3. Research Center of Mountain Torrent Geological Disaster Prevention and Control Engineering Technology, Ministry of Water Resources, Wuhan 430010, China
  • Received:2023-07-10 Revised:2023-11-06

Abstract: Slope ecological restoration is an important component in the construction of power transmission projects. Traditional spray-sowing technology uses cement as binding materials, which results in a low germination rate of vegetative substrate, restricting the ecological restoration efficiency. Taking the high-steep slope of power transmission construction project in the red soil area as research object, this study used seaweed polysaccharide, which is a polymer chemical binder, to replace cement, with addition of ecological fertilizer and fiber. Indoor direct shear tests and pot experiments were carried out with bermudagrass as the plant species to analyze the mechanical and planting properties of the neotype spray-sowing substrate in red soil. Results showed that seaweed polysaccharide and fiber were the main factors affecting the cohesion of the neotype spray-sowing substrate. Bermudagrass germination rate was negatively correlated with seaweed polysaccharide content, while was significantly positively correlated with ecological fertilizer content, and exhibited no significant correlation with fiber content. The optimum content of seaweed polysaccharide to improve the substrate cohesion was 1%. The addition of fiber could also improve the cohesion, and the maximum cohesion was achieved when fiber content was 0.75%. When the content of seaweed polysaccharide was 1% and the content of ecological fertilizer was 5%, the bermudagrass germination reached 100%. The research results would provide new technical references for ecological restoration of high-steep slopes in red soil areas.

Key words: High steep red soil slopes, Spray-mixed vegetation substrate, Seaweed polyacrylamide, Mechanical properties, Vegetation performance

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