Abstract:In order to clarify the blockage and control law of nitrogen and phosphorus in simulated runoff under different conditions, five vegetative buffer strips were constructed with control, Cynodon dactylon, Zoysia matrella, Festuca elata and Ophiopogon japonicus, and the blockage and control effects on nitrogen (N) and phosphorus (P) in surface flow and seepage were explored by simulating runoff with different pollutant concentrations. The results showed that compared with the control, the vegetative buffer strips significantly improved the interception ability of the soil system on runoff and pollutants such as nitrogen and phosphorus in the incoming water, and the average runoff reduction rates of the filter strips of Cynodon dactylon, Zoysia matrella, Festuca elata, Ophiopogon japonicus and the control group were 56.10%, 54.28%, 63.16%, 60.53% and 39.10% respectively under three hydraulic load intensities. The runoff reduction rates of all four plantings were significantly higher than those of the control (p<0.05). All four plantings significantly reduced the surface infiltration ratio and improved the infiltration capacity of the soil. The increase in hydraulic load intensity reduced the removal efficiency of NH4+—N and total P (TP) in the vegetated filter zone, but the reduction in the removal rate of the vegetated treatment was less than that of the control. Within a certain range, the removal rates of total N (TN), NO3-—N and TP in the seepage increased with the increase of N and P concentrations in the incoming water. Under a certain hydraulic load, the vegetative with low root to shoot ratio has a stronger ability to reduce runoff.