Vegetation filter strips (VFS) have been shown to effectively intercept water flow and remove nitrogen. Studies of the vegetation effects on water flow and nitrogen transport are typically studied based on qualitative analyses with species, layouts, growth stage, seasonal changes, and other vegetation conditions and did not considered quantification based on plant traits. In this study, the transport path and retention efficiency of nitrate nitrogen (NO₃-N) in VFSs are investigated from the view of the plant specific trait effects by simulating runoff experiments using three grassed VFSs (centipede grass, tall fescue, and vetiver grass), as well as a bare VFS under different slope gradients (2%, 7%, and 12% slope gradients). The primary grass traits (stem spacing, root depth, root length density, and nitrogen total uptake) were measured, and the responses of water flow and NO₃-N loss above and below ground to those were quantitatively assessed using the grey correlation analysis method. Results indicated that grasses and slope gradient significantly influenced the water flow and NO₃-N loss in general, except the NO₃-N loss concentration of the surface flow, in which the tall fescue VFS showed the highest NO₃-N total retention rates under each slope condition. Considering the impact of specific grass traits, stem density and root length density has the greatest effects on the surface flow and the subsurface flow respectively, while the effect of roots was lower than that of stems on NO₃-N loss below ground. Additionally, the NO₃-N loss mass in the surface and subsurface flow were mostly related to the water flow volume and the NO₃-N loss concentration respectively. This indicated that grass traits that reduce water flow should be considered more to control the NO₃-N loss mass above ground, whereas the grass traits reducing NO₃-N loss concentration should be considered more to control the NO₃-N loss mass below ground.

植被滤条（VFS）已被证明可以有效拦截水流并去除氮。通常基于对物种，布局，生长期，季节变化和其他植被条件的定性分析来研究植被对水流和氮的影响，而没有考虑基于植物性状的量化。在这项研究中，硝酸盐氮（NO ₃从植物特定性状效应的角度研究了VFS中的-N），方法是使用三种带草的VFS（cent草，高羊茅和香根草），以及在不同坡度梯度下裸露的VFS（2％， 7％和12％的坡度）。测量了主要草的性状（茎距，根深，根长密度和氮素吸收总量），并使用灰色关联分析法定量评估了水流和地上和地下NO ₃ -N损失对土壤的响应。。结果表明，草和坡度对水流和NO ₃ -N损失总体上有显着影响，除了表面流的NO ₃ -N损失浓度外，高羊茅VFS表现出最高的NO。在每个斜坡条件下，总保留率为₃ -N。考虑到特定草性状的影响，茎密度和根长密度分别对地表流和地下流的影响最大，而根对地下NO ₃ -N损失的影响低于茎对根流的影响。另外，表面和地下流中的NO ₃ -N损失质量分别主要与水流量和NO ₃ -N损失浓度有关。这表明应该更多地考虑减少水流的草性状，以控制地面上的NO ₃ -N损失量，而减少NO ₃ -N损失浓度的草性状，应更多地控制NO。地下₃ N损耗质量。