Effects of vegetation restoration methods on vegetation growth indexes and soil physical and chemical properties of spoil ground in red-soil hilly region

Taking an abandoned soil field of Jiangxi expressway as an example, the key techniques of vegetation restoration in the abandoned soil field of red-soil hilly area was discussed. Based on the understanding of the climatic characteristics and geological conditions of the spoil ground, three vegetation schemes and two basic fertilizer schemes were set up by soil testing formula and grass irrigation mixed sowing method. The three vegetation schemes were: Vegetation allocation 1 (Bermudagrass + Bahia grass + Alfalfa + White clover + Cassia corymbosa+ Amorpha fruticosa), Vegetation allocation 2 (Alfalfa + White clover + Bermudagrass + Horse thorn + Beautiful lespedeza), and conventional spray seeding (Bermudagrass + Alfalfa + Horse thorn). The two basic fertilizer schemes were Fertilizer scheme 1 (50 g/m² compound fertilizer) and Fertilizer scheme 2 (100 g/m² compound fertilizer). The vegetation restoration and soil physical and chemical properties were analyzed to determine the best combination. The results showed that: under Vegetation allocation 1 + Fertilizer schemes 2, the vegetation grew well, the density was high, and the coverage rate reached 80% after one month. And the physical and chemical properties of soil were significantly changed compared with other treatments. Compared with conventional spray seeding, the soil capacity decreased by 0.17 g/cm³, and the total porosity of soil, organic matter and alkaline nitrogen increased by 19.68%, 62% and 8%, respectively, which could effectively solve the problem of uneven green coverage and long time in the spoil ground, prevent and reduce soil and water loss, and thus have great economic and ecological benefits.