Denitrification Potential of Marsh Soils in Two Natural Saline-alkaline Wetlands  

作　　者：BAI Junhong ZHAO Qingqing WANG Junjing LU Qiongqiong YE Xiaofei GAO Zhaoqin 

机构地区：[1]State Key Laboratory of Water Environment Simulation,School of Environment,Beijing Normal University

出　　处：《Chinese Geographical Science》2014年第3期279-286,共8页中国地理科学（英文版）

基　　金：Under the auspices of National Natural Science Foundation of China(No.51179006,51379012);Program for New Century Excellent Talents in University(No.NCET-10-0235);Fok Ying Tung Education Foundation(No.132009)

摘　　要：Little information is available on denitrification potential of marsh soils in natural saline-alkaline wetlands. The denitrification potentials of an open wetland in the floodplain(Erbaifangzi wetland) and a closed wetland(Fulaowenpao wetland) in backwater areas in Jilin Province of Northeast China were monitored by an anaerobic incubation at 30℃ for 25 days. Our results showed that the relative denitrification index(RDI) increased gradually with incubation time, and showed a rapid increase in the first 5 days of incubation. The RDI values declined quickly from surface soils to subsurface soils and then kept a small change in deeper soils along soil profiles over the incubation time. Denitrification proceeded much faster in the top 20 cm soils of open wetland than in the closed wetland, whereas no significant differences in RDI values were observed in deeper soils between both wetlands. The RDIs were significantly negatively correlated with bulk density and sand content, while a significantly positive correlation with clay content, soil organic matter, total nitrogen and phosphorous. The maximum net NO–3-N loss through denitrification in 1 m depth were higher in the open wetland than the closed wetland with higher soil pH values. Future research should be focused on understanding the influencing mechanisms of soil alkalinity.Little information is available on denitrification potential of marsh soils in natural saline-alkaline wetlands. The denitrifica- tion potentials of an open wetland in the floodplain （Erbaifangzi wetland） and a closed wetland （Fulaowenpao wetland） in backwater areas in Jilin Province of Northeast China were monitored by an anaerobic incubation at 30℃ for 25 days. Our results showed that the relative denitrification index （RDI） increased gradually with incubation time, and showed a rapid increase in the first 5 days of incuba- tion. The RDI values declined quickly from surface soils to subsurface soils and then kept a small change in deeper soils along soil pro- files over the incubation time. Denitrification proceeded much faster in the top 20 cm soils of open wetland than in the closed wetland, whereas no significant differences in RDI values were observed in deeper soils between both wetlands. The RDIs were significantly negatively correlated with bulk density and sand content, while a significantly positive correlation with clay content, soil organic matter, total nitrogen and phosphorous. The maximum net NO3--N loss through denitrification in 1 m depth were higher in the open wetland than the closed wetland with higher soil pH values. Future research should be focused on understanding the influencing mechanisms of soil alkalinity.

关 键 词：relative denitrification index potential net denitrification rate marsh soil saline-alkaline wetland 

分 类 号：X703[环境科学与工程—环境工程]