Experimental investigation of vegetative buffer strips in qualitative and quantitative conservation of water and soil

Iran has an arid and semi-arid climate as well as a more unstable ecosystem than humid regions; so the importance of water and soil resources conservation becomes higher in this country. The use of vegetative buffer strips is an effective strategy to reduce pollutions in surface waters as well as soil erosion. The present research has been conducted with the aim of study the effect of runoff rate, plant age and plant species on the efficiency of vegetative buffer strips to control runoff quality and quantity in Sari, Mazandaran, Iran. 1×10 m experimental plots were used and artificial runoff with two rates equal to the runoff generated by a precipitation with 25 and 100 years return period. The results indicated that the efficiency of vegetative buffer strips containing vetiver grass and turf grass affected by the runoff with a rate equal to the runoff generated by a precipitation with 25 years return period was higher than the buffer strips affected by the runoff with a rate equal to the runoff generated by a precipitation with 100 years return period, during the study period. Also, it was found that the efficiency of vegetative buffer strips to control runoff quality and quantity is affected more by the flow properties than characteristics of buffer strips, their plant age and species, when runoff rate is high. Two studied plant species including vetiver grass and native turf grass also showed a different performance to reduce runoff volume and its pollutants. On the other hand, variation of the plants’ age caused different efficiency for the studied vegetative buffer strips.