中文摘要：

为了研究茭白-茨菰湿地系统对节水灌溉稻田排水中氮素的原位消减效果,探讨不同湿地-稻田面积比对系统氮素去除效果的影响,通过大田试验观测,分析了稻田排水进入湿地后氮素浓度的变化规律和湿地-稻田面积比（1∶10,1∶7和1∶4）对氮素去除效果的影响。结果表明,稻田排水进入湿地系统经过7-14 d的净化后其铵态氮（NO＋4-N）、硝态氮（NO-3-N）和总氮（TN）的浓度下降范围可以维持在83.6%-88.7%、59.6%-94.3%和72.6%-88.9%范围内,不同湿地-稻田面积比间氮素的去除率有所差异,但差异不大。此外,氮素浓度在排水进入湿地系统后的前3-6 d内其去除效果明显,均呈指数趋势下降,且其去除率均达到56%以上,而后2-4 d则趋于平稳降低,其去除率均低于30%。总体上来看,1∶4湿地对氮素负荷截留量最小,1∶10湿地截留量最大,但不同湿地对氮素负荷的去除率相差不大,均维持在93%-98%以内。

英文摘要：

To reveal the nitrogen removal effect in drainage from water-saving irrigated rice fields by using water bamboo-arrowhead wetland system, and the influence of different wetland-paddy area ratios on nitrogen removal efficiency of the system. The dynamics of water nitrogen concentration in the wetlands and the impact of wetlands-paddy area ratio on nitrogen removal effect are analyzed based on field experiments with three different wetlands-paddy area ratios （ 1 ： 10, 1 ： 7 and 1 ： 4）. The concentrations of ammonium nitrogen （ NH--N）, nitrate nitro- gen（NO--N） and total nitrogen （TN） in drainage water has reduced by 83.6%- 88.7%, 59.6% - 94.3% and 72.6% - 94.3% after 7 - 14 days purification in the wetlands. The difference in the reduction rates among different wetland - paddy area ratio is not significant. The reduction rate of nitrogen concentration in drainage water has reduced exponentially along with the time. In addition, the reduction rate is much larger during the first 3- 6 days （higher than 56% ） than during the later 2 - 4 days （less than 30% ）. Overall, the 1 ： 4 wetland to intercept a minimum amount of nitrogen load, and the 1 ： 10 wetlands intercept the maximum, but the differences between different wetlands on the removal rate of nitrogen load are not significant, all of which are maintained betwen 93% - 98%.