Ecological restoration of highway slope by covering with straw-mat and seeding with grass–legume mixture

• Ecological of highway slope with straw-mat covering.
• The slope covered with straw-mat could enhance the vegetation growth.
• The soil physicochemical properties were improved by ecological restoration technology.
• The technology also embodied the economic and environmental friendliness.

Highway construction has caused certain negative impacts on the ecological environment, particularly in mountainous areas. The vegetation recovery of highway slopes can reduce the harmful effects, especially in the initial stage of highway construction. In 2014, our research was carried out on a restored highway slope in the Wanxi Dabie mountain areas, China. In this study, research sites were established on three adjacent highway slopes and one in the nearby forest. The effects on the soil moisture, soil temperature, vegetation growth and soil physicochemical properties were surveyed by both laboratory and field experiments. The results showed that the slope covered with topsoil and straw-mat was more effective in enhancing vegetation growth by reducing soil evaporation and regulating the soil temperature, improving the aesthetic quality of the road environment rapidly. In addition, the soil physicochemical properties were significantly improved along with the initial vegetation recovery of the highway slopes. This effective ecological restoration technology also embodied the characteristics of economic and environmental friendliness. The derivation of unit cost was only US$ 6 m−2, which was suitable for developing countries. Consequently, the study provided a typical case of vegetation recovery on highway slopes that has great potential for promotion and application in other areas.