Background Among the many geological disasters on slopes, most of them are caused by failure to take timely and appropriate reinforcement measures. In recent years, with the national emphasis on the ecological environment, the topic of vegetation slope protection has gradually risen. In the mountainous area of Yuan′an county, Hubei, due to the large number of newly reclaimed tea (Camellia sinensis) gardens and lack of management, some areas have suffered from serious soil erosion. Therefore, this paper studied the effect of tea tree planting on the anti-scour performance of slope and the main factors affecting the anti-scour performance of tea tree slope, which was of great significance for analyzing the effect of tea tree planting on slope soil and water conservation.

Methods A slope model was designed based on the regional environment of a tea farm in Yuan′an county, and the artificial climate simulation system environment box (model CABR-MCB) was applied to simulate the rainfall erosion test under the condition of extremely heavy rain. Then the effect of tea tree planting on the erosion resistance of slope was studied by calculating the runoff rate and anti-scour coefficient. Then the factors affecting the anti-scour performance of tea tree slope were analyzed based on the results of water stability aggregate content determination and root fractal scanning. Finally, SPSS software was used to analyze the correlation and significance of each influencing factor against the anti-scour coefficient.

Results The runoff rate and anti-scour coefficient were calculated according to the erosion test data. The results indicated that the runoff first increased to the peak value, and then fluctuated and tended to be stable. Tea tree slope had the best runoff rate, which was smaller than the native vegetation slope and the plain soil slope (1.224 < 1.280 < 1.398). Compared with the native vegetation slope and the plain soil slope, the anti-scour coefficient of tea tree slope increased by 12.8% and 53.2%, respectively. The determination results of water stable aggregate content were as follows: Tea tree slope > native vegetation slope > plain soil slope. The above-ground development (vegetation coverage) of tea tree slope was better than that of native vegetation slope (95% > 87%). The development of the underground part of the tea tree slope vegetation was also better than that of the native vegetation slope.

Conclusions After analysis, tea planting is conducive to improving the scour resistance of slope, which is affected by vegetation coverage, root development, water stability aggregate content, scouring time and scouring depth. The results of this research may provide ideas for solving the problem of soil erosion caused by newly cultivated tea plantations in Yuan ′an area.