水生植物对农田排水沟渠中氮、磷的截留效应

为有效阻控农田土壤流失氮、磷通过沟渠进入水体,通过动态模拟实验研究对比不同排水沟渠对农田流失氮、磷的截留作用,同时通过静态模拟实验重点探讨了水生植物对氮、磷在水-沉积物-水生植物这一微观系统中的截留机理.结果表明:沟渠中的水生植物茭白和菖蒲对氮、磷的截留和转化有明显的促进作用;水生植物的存在可以加速氮、磷界面交换和传递,从而使上覆水中氮、磷含量快速减少;沉积物间隙水中氮、磷含量的变化受界面交换、沉积物吸附、微生物转化及植物吸收等各方面因素影响,水生植物调整并加强氮、磷的各种转化,植物的存在使得间隙水中氨氮及磷酸盐含量降低并呈现规律变化.

Study on the Interception of Nitrogen and Phosphorus by Macrophyte in Agriculture Drainage Ditch

In order to effectively intercept and wipe off nitrogen and phosphorus of agricultural soil, the interception effect of different agriculture drainage ditch on. nitrogen and phosphorous was studied by dynamic simulation experiment, and further research was carried out to reveal the mechanism of absorption and removal of nitrogen and phosphorous in the ditch by macrophyte such as caduueiflora and acorus calamus by static simulation experiment. The result indicates that the caduuciflora and acorus calamus in the ditch can accelerate the interface exchange by which nitrogen and phosphorous of superjacent water is reduced and can obviously speed .up the intercept, the transfer and transformation of nitrogen and phosphorous. The change of nitrogen and phosphorous contents in the sediment interstitial water is affected by multiple factors, such as interface change, sediment adsorption, microbial transformation and plant absorption. The macrophyte can adjust and strengthen various transformation of nitrogen and phosphorous, and the plants can reduce the concentration of ammonia nitrogen and phosphate, with some rules of change.