Characteristics and applications of ecological soil substrate for rocky slope vegetation in cold and high-altitude areas

Abstract

Ecological restoration of steep rocky slopes generated by road cutting is usually difficult especially, in the cold and high-altitude environment, which is unfavorable for the growth of vegetation. With the focus on slope vegetation, an ecological soil substrate, synthesized with polyacrylamide (PAM), carboxymethyl cellulose (CMC), and Fly ash (FA) as the main components, was developed for spray seeding on the rocky slopes in cold and high-altitude regions, to provide a favorable environment for vegetation growth. The compositional effect of individual compound addition on the growth of vegetation and substrate properties was investigated using an orthogonal array experimental design. Based on ANOVA and orthogonal analysis, an ecological soil substrate (PCF) with 400g/m3 PAM, 600g/m3 CMC, 1500g/m3 FA, and 50L/m3 of water was decided as the optimum PCF substrate. The optimum PCF substrate was then sprayed on a steep rocky slope in a cold and high-altitude region in Sichuan, China, for two years. The vegetation, as well as the physico-chemical properties, nutrient content, and mechanical properties of the field soil substrate, were examined over this duration. The field verification shows that the proposed PCF substrate is able to provide desirable nutrient contents and excellent physical and mechanical properties for vegetating the steep rocky slopes in cold and high-altitude areas.