VEGETATIVE FILTER STRIP EFFECTS ON SEDIMENT CONCENTRATION IN CROPLANDRUNOFF

Little has been done to evaluate the effectiveness of vegetative filte r strips (VFS) in controlling sediment loading of surface waters from cropland soil erosion. We established study areas on 7% and 12% grades to evaluate VFS effects on sediment concentration, runoff volume, and soil loss from an 18.3-m continuous fallow strip. We designed a colle ctor-sample splitter to collect representative runoff subsamples. We p laced collectors at six intervals within the bromegrass filter ship an d recorded data from 13 rainfall events. The initial 3.0 m of the VFS removed more than 70% of the sediment from runoff while 9.1 m of the V FS removed 85%. Little decrease in sediment concentration was observed with greater VFS widths. The 12% grade had greater runoff and soil lo sses at all VFS widths than the 7% grade. The VFS promoted infiltratio n, reduced runoff volumes, and decreased runoff sediment concentration .