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Soil and water conservation in natural and cultivated areas is a major concern for humankind. However, there are severe problems with degraded hillslopes due to bare soils in northern Iran, which are one of the most important factors driving land degradation processes. Subsequently, soil erosion, pollutant transport, and/or nutrient impoverishment are affecting large territories; therefore, rapid and inexpensive soil conservation measures need to be implemented. The use of vegetative buffer strips could be an effective strategy to reduce pollutant transport as well as soil erosion.Thus, this research aimed to investigate the possible efficiency of two different vegetative buffer strips composed of vetiver-grass (Chrysopogon zizanioides) and native turf-grass (Festuca arundinacea) at reducing runoff and soil losses as well as nitrate transport on a representative degraded hillslope with bare soils in Mazandaran, Iran.Twelve 10 m 2 experimental plots were tested over 1 year using a runoff simulator that produced overland flow that corresponded to the 25-and 100-year return period rainfall events. The plots with bare soils had the highest runoff volumes (30.5 and 55.4 L m −2 ), sediment concentrations (101.2 and 430.6 g L −1 ), and nitrate concentrations (10.4 and 37.6 mg L −1 ). Vetiver was the most useful tool to reduce runoff, soil loss, and nitrate concentration, with values of 13.4 and 28.6 L m −2 , 13.4 and 90.9 g L −1 , and 2.9 and 16.4 mg L −1 , respectively. Of the treatments investigated, vetiver provided the most rapid cover and was the most efficient at preventing soil erosion and nitrate transport directly after plantation.

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Soil erosion is one of the most serious environmental issues in the world. The use of vegetative buffer strips is an effective strategy to reduce surface water pollutions as well as soil erosion. The present research has been conducted with aim to study the efficiency of buffer strips in runoff volume and sediment control using experimental plots. In this regard, twelve experimental plots with the dimensions of 1 m × 10 m were provided, and runoff samples were collected monthly to measure runoff volume and sediment. Vetiver grass and tall fescue were used as the plant species of the studied vegetative buffer strips. It was found that, vegetative buffer strips reduced the runoff volume up to 97% and sediment concentration up to 96%. Vetiver grass showed a high efficiency in runoff and sediment control; but, the maximum efficiency is achieved when this species is used along with a plant similar to the tall fescue in terms of density and uniformity. Also, periodic cutting the plants and cleaning the buffer strips can be considered as effective strategies to prevent vegetative buffer strips acting as the source of sediment.

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