Effectiveness of Riparian Vegetated Filter Strips in Removing Agricultural Nonpoint Source Pollutants in Agricultural Runoff from the Liao River Area, China

Abstract

Riparian vegetated filter strips (RVFS) can effectively intercept agricultural non-point source pollution (ANSP) into a water body and reduce the risk of water body pollution. The present study evaluates the long-term effectiveness of different types and lengths (5 m, 9 m, 13 m) of RVFS in reducing the suspended solids (SS) and nutrients from agricultural runoff. Three field experimental plots (T1-T2-T3) planted with weeds, sweet clover (Melilotus suaveolens L.) and sweet clover/Chinese wingnut (Pterocarya stenoptera C. DC.) were established adjacent to the agricultural edge from 2011 to 2018. The runoff volumes, SS, and nutrients concentrations were determined at each effective runoff event during the study periods. The results indicated that all RVFS (T1, T2, and T3) reduced the mass of the nutrients rather than the concentration in all runoff events. In the rainfall events, the pollutants were reduced significantly in the presence of RVFS. The removal efficiency of T2 and T3 amounted to 79% and 84% for SS within the first 5 m, which was significantly higher than T1(61%). The 9 m-long T3 caused a significant reduction in the mean total phosphorus (TP) and dissolved phosphorus (DP) by 84% and 82%, respectively. More than 70% of the pollutants from rainfall runoff could be controlled by a 13 m RVFS. The snow-melt events increased the risk of ANSP migrating to streams, especially for the DP. However, the Chinese wingnut strip increased the filtering capacity of the DP as compared

Reduction of nitrogen loss in runoff from sloping farmland by a ridged biochar permeable reactive barrier with vegetated filter strips

“…The literature suggests that VFS may struggle to reduce the movement of more total dissolved forms of N (e.g., nitrate) and P into surface waters, although relatively high trapping efficiencies have been reported for these forms (Yang et al, 2015). In a recent study, Tang et al evaluated the long-term effectiveness of different types and lengths of VFS in reducing suspended solids and nutrients in agricultural runoff (Tang et al, 2021). They found that VFS (9 m, 13 m) reduced suspended solids to 79% and 84% of the original amount, in consistence with the findings of the present study.…”

“…Vegetated filter strips (VFS), designated areas of land intended to create a buffer between agricultural land and ecologically significant aquatic or terrestrial environments. They demonstrated efficacy in intercepting agricultural non-point-source pollution before it enters a water body (Prosser et al, 2020;Tang et al, 2021). Research consistently demonstrates that VFS can efficiently capture a substantial portion of the total phosphorus and nitrate load in field runoff, preventing its entry into surface water (Janssen et al, 2018;Lyu et al, 2021).…”