不同宽度草皮缓冲带对农田径流氮磷去除效果研究

在前期调查及试验研究的基础上，通过设置不同宽度的混播草皮缓冲带，研究其对农田径流总氮、总磷的去除效果。结果表明:在总氮、总磷进水平均浓度分别为17.89，1.04 mg/L的试验条件下，3～12 m宽度的混播草皮缓冲带对总氮、总磷具有一定的去除效果，且随着缓冲带宽度的增加而不断提高，其中对渗流水总氮、总磷的去除效果优于地表径流水，当草皮缓冲带宽度为12 m时，对农田径流中总氮、总磷的去除率可达80%。最后通过数值拟合的方法计算当总氮、总磷去除率均达70%时，混播草皮缓冲带所需的适宜宽度。

Effects of Grass Buffer Strips with Different Widths on Nitrogen and Phosphorus Removal Efficiency of Farmland Runoff

On the basis of preliminary survey and experimental study, we researched the removal efficiency of nitrogen and phosphorus in farmland runoff by setting mixed grass buffer strips with different widths. The results showed that under the test condition of nitrogen and phosphorus with average concentrations of 17.89 mg/L and 1.04 mg/L, respectively, 3~12 m width of mixed grass buffer strips had a certain removal effect on nitrogen and phosphorus, and the removal effect constantly improved with strips bandwidth increase, nitrogen and phosphorus removal efficiency in seepage water was better than in surface runoff. When the width of grass buffer strips was 12 meters, the removal rates of nitrogen and phosphorus in farmland runoff reached up to 80%. Finally, the data fitting method was used to calculate the optimal widths of mixed grass buffer strips when the nitrogen and phosphorus removal rates reached to 70%.