Effects of Herbaceous Filter Strip on soil erosion control and nutrients conservation

Herbaceous Filter Strip (HFS) built between the source of the pollution and the water body can retain sediments and thus limit soil erosion intensity, conserve soil nutrients and protect the water body from pollution. However, the trapping efficiencies of the HFS composed of diverse plant species are decided by many factors, especially the width of the HFS. The impact of width on the efficiency of the HFS to retain runoff, sediments and soil nutrients was assessed by means of a field experiment with vegetation developing spontaneously. Three kinds of HFS width were tested, 10 m width-treatment 1 (Tr1), 20 m width-treatment 2 (Tr2) and 25 m width-treatment 3 (Tr3). Measured retention efficiencies were compared with control (Ct), plot with no vegetation. The spontaneously developed HFS has a stable and good trapping efficiency of runoff and sediment through plant growth stages due to its morphological diversity and homogeneous plant cover. Moreover, the HFS with a width of 25 m is wide enough to trap most runoff and sediments for the study area.