A Preliminary Study Of Herb Vegetative Filter Strips In The Prevevtion Of Agricultural Non-point Source Pollution

Chemical fertilizer and herbicide are widely used in agricultural production. These chemicalsubstances including nitrogen, phosphorus and herbicide go into water and subsequently causewater eutrophication. So it is an important problem to prevent agricultural non-point sourcepollution. As an ecological engineering, herb vegetative filter strips were considered as theeffective practice to prevent agricultural non-point source pollution. This unclear water scourexperiment was conducted to evaluate the effects of herb vegetative filter strips such asPennisetum (Pennisetum alopecuroides (Linn.) Spreng and Arundinella (Arundinella hirta(Thunb.) C. Tanaka) grass hedges on the loss of runoff, soil, nitrogen, phosphorus, chloride ionand atrazine. The results shows that the decrease of these agricultural non-point source pollutantsdue to herb vegetative filter strips could reach83%,90%,95%,88%,98%and96%, respectively.The content of phosphorus and atrazine gradually decreased by the vegetative filter strips withthe increasing time and the degradation rate gradually becomes very slow. The content ofphosphorus and atrazine becomes lower through the herb vegetative filter strips which its widthwas3m. The tests indicate that the proper width of herb vegetative filter strips was3m at least.The herb vegetative filter strips also can absorb phosphorus and atrazine by absorption anddegradation. And the concentration of phosphorus and atrazine gradually decreased with theincreasing time. Therefore, the herb vegetative filter strips can significantly reduce runoff, soil,nitrogen, phosphorus, chloride ion and atrazine and will be helpful to prevent agriculturalnon-point source pollution.