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The goal of this research is to investigate strategies to increase the erosion resistance of the slope surface during the early stages of vegetation concrete construction, as well as to offer a scientific foundation for improving vegetation concrete formulation. Simulated rainfall experiments were carried out at 2 different slope gradients (50° and 60°), 2 different rainfall intensities (60 and 120 mm·h−1), and 4 treatments (CK-no additive, 0.4% P-polyacrylamide, 4% C-biochar, and 0.4% F-palm fiber). PAM, palm fiber, and biochar significantly reduced the initial runoff time of the vegetation concrete slope by an average of 47.03%, 46.41%, and 22.67%, respectively (p < 0.05). The runoff rate of each slope under different conditions increased with the expansion of rainfall duration and then fluctuated and stabilized, whereas the erosion rate decreased and then fluctuated and stabilized. PAM and palm fiber both increased runoff rates while decreasing erosion rates, but biochar increased both runoff rates and erosion rates. The runoff reduction benefits of PAM, palm fiber, and biochar were −69.84~−1.97%, −68.82~−14.28% and −63.70~−6.80%, respectively, while the sediment reduction benefits were 69.21~94.07%, −96.81~−50.35%, and 36.20~60.47%, respectively. PAM and palm fiber both have obvious sediment reduction benefits and can be used in the ecological restoration of high and steep slopes in areas with heavy rainfall. [ABSTRACT FROM AUTHOR]

[Display omitted] • Zeolite (ZL) combined with biochar (BC) performed better than BC alone. • ZL alleviated the negative effect of BC on geotechnical properties of vegetation concrete (VC). • ZL strengthened positive effect of BC by adsorbing its aged broken small particles. • Adding ZL did not have a negative effect on plant growth in VC. • BC (2 wt%) + ZL (2 wt%) was the recommended amounts. The mechanical strength and fertility retention capacity of vegetation concrete (VC) are insufficient when prepared using sandy soil. Biochar (BC) has been used to improve the fertility retention capacity of VC; however, it negatively affects mechanical strength and is prone to aging. In this study, a novel method using the synergistic effects of zeolite (ZL) and BC was proposed. Four different ZL contents (0%, 1%, 2%, and 4% of the planting soil weight) were investigated to determine the influence of ZL on the physical, mechanical, chemical, and biological properties of sandy VC. The results reveal that the ZL not only alleviated the negative effect of the BC but also enhanced its positive effects. In particular, by adding ZL, the porosity, permeability, and nutrient (ammonium nitrogen and nitrate nitrogen) leaching loss rates of the sandy VC decreased, whereas the cohesion, internal friction angle, matric suction, dissolved organic carbon content, and microbial biomass increased. In addition, the secondary hydration reaction between the ZL and calcium hydroxide enhanced the mechanical properties of the VC, and the adsorption of aged broken small BC particles on the ZL prolonged the fertility retention of the BC. The secondary hydration reaction of ZL occurs first, and then the remaining ZL absorbs the small BC particles. Considering the effects and cost of ZL, the recommended amount of ZL to be mixed with sandy VC is 2–4 wt%. [ABSTRACT FROM AUTHOR]