Abstract: In order to further explore the suitable slope ecological protection substrate for the Southern Shaanxi phyllite area, the abandoned phyllite gravel in Southern Shaanxi was used as the main substrate, and straw, cement, organic fertilizer, peat soil, and water retaining agent were added to form the slope protection substrate. An orthogonal experiment was designed and the local herbaceous plant tall fescue from Southern Shaanxi was selected as the experimental grass species for potted planting.Using comprehensive scoring method and range analysis method to analyze the optimal ratio of slope protection substrate and the importance of various factors on the growth of tall fescue, and finally indoor simulated rainfall erosion test was used to verify the strength of the substrate. The results showed that in the Southern Shaanxi region, the optimal substrate ratio suitable for the growth of tall fescue was 4% straw content, 4% cement content, 5% organic fertilizer content, 8% peat soil content, and 0.25% water retaining agent content. According to the analysis of range results, it could be concluded that the factors affecting the growth of tall fescue were cement, straw, peat soil, water retaining agent, and organic fertilizer in descending order. The indoor simulated rainfall erosion test showed that the slope protection substrate in this study had good erosion resistance and strong practicality.

Key words: phyllite, slope protection substrate, orthogonal experiment, anti erosion, performance, Southern Shaanxi