摘要
以鄱阳湖流域典型围垦区—蒋巷联圩为研究区域,解析了水稻生长期内稻田-多级沟渠系统氮磷时空变化特征.研究结果表明,分蘖期稻田-多级沟渠系统水体的TN浓度显著高于其他时期(p<0.05),是面源污染的主要贡献时期.相较于稻田水,沟渠水的NO_(3)^(-)-N浓度显著高于NH_(4)^(+)-N浓度(p<0.05),在水稻生长期内呈先降低后升高的变化趋势,且NO_(3)^(-)-N主要来自一级沟渠.稻田水的磷浓度表现为先升后降,而沟渠水的磷浓度为下降趋势.在空间尺度上,稻田水的氮、磷浓度在上段最高,中段最低,中段氮形态主要为NO_(3)^(-)-N;沟渠水的氮浓度在中段高,TN、NH_(4)^(+)-N、NO_(3)^(-)-N浓度分别为(4.50±6.16)、(0.57±1.98)、(1.63±1.49)mg·L^(-1),而磷浓度在上段最高(TP为(0.14±0.09)mg·L^(-1));上段和中段二级沟渠水的氮、磷浓度低于其他沟渠.稻田水的氮形态主要为NH_(4)^(+)-N,而沟渠水的氮形态为NO_(3)^(-)-N,磷以颗粒态为主(69.84%).集中降雨时期(分蘖期和长穗期),氮、磷浓度在从稻田到三级沟渠的流向上表现为升高趋势,受汇水类型及沟渠物理形态影响,其中二级自然沟渠水的氮磷平均浓度最低,而伴有城镇生活污水汇入的一级沟渠水的氮磷平均浓度最高.
Jiangxiang Lianwei,a typical reclamation area of the Poyang Lake Basin,is selected in this study to investigate spatiotemporal characteristics of nitrogen and phosphorus in the paddy field and multi-ditch drainage system during the paddy growth period.Research results indicate that the total nitrogen(TN)concentration in both paddy field and ditch water were signifucantly higher compared to other stages(p<0.05),with mean concentration of(7.91±9.50)mg·L^(-1)and(7.23±6.10)mg·L^(-1),respectively.The nitrate nitrogen(NO_(3)^(-)-N)concentrations in paddy field water peaked during the seedling stage and the filling stage in ditch water(p<0.05),with measurements at(1.44±1.55)mg·L^(-1)and(2.52±1.46)mg·L^(-1),respectively.The phosphorus concentration in paddy field water increased initially and then decreased,while the overall trend in ditch water showed a persistently increasing trend.At the spatial scale,nitrogen and phosphorus concentrations in paddy field water were higher in the upper reaches,with TN and total phosphorus(TP)concentrations of(6.23±13.77)mg·L^(-1)and(0.11±0.09)mg·L^(-1),respectively,in contrast to the middle reaches,which showed lower levels of(3.17±4.43)mg·L^(-1)and(0.09±0.04)mg·L^(-1),respectively.The phosphorus concentrations in the ditch water were highest in the upper section,with TP and particulate phosphorus(PP)concentrations of(0.14±0.09)mg·L^(-1)and(0.10±0.07)mg·L^(-1),respectively,while nitrogen concentrations were relatively diminished,with TN concentration at(2.73±2.26)mg·L^(-1)and(0.19±0.41)mg·L^(-1)for ammonium nitrogen(NH_(4)^(+)-N).Nitrogen concentrations were higher in the middle section,with TN,NH_(4)^(+)-N,and NO_(3)^(-)-N concentrations of(4.50±6.16),(0.57±1.98),and(1.63±1.49)mg·L^(-1),respectively.In the multi-level ditch system of the paddy field,phosphorus mainly existed in particulate form,accounting for more than 69.84%of the total phosphorus.Influenced by the type of water inflow and the physical structure of the ditches,the primary ditch,which is subject to urban domestic sewage imputs,had the highest average nitrogen and phosphorus concentrations,while the secondary natural ditch had the lowest.
作者
黄建榕
杜必发
李昆
胡大洲
桂双林
朱利英
魏源送
HUANG Jianrong;DU Bifa;LI Kun;HU Dazhou;GUI Shuanglin;ZHU Liying;WEI Yuansong(School of Resources and Environment,Nanchang University,Nanchang 330031;State Key Joint Laboratory of Environmental Simulation and Pollution Control,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085;Laboratory of Water Pollution Control,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085;University of Chinese Academy of Sciences,Beijing 100049;Energy Research Institute,Jiangxi Academy of Sciences,Nanchang 330096;Fujian Governmental Investment Projects Appraisal,Fuzhou 350003)
出处
《环境科学学报》
北大核心
2025年第3期251-259,共9页
Acta Scientiae Circumstantiae
基金
长江生态环境保护修复城市驻点跟踪研究项目(No.2022-LHYJ-02-0505-01,2019-LHYJ-01-0.000211-18)。
关键词
鄱阳湖
围垦区
稻田-沟渠系统
水稻生长期
氮磷变化
时空分布
Poyang Lake
reclamation areas
paddy field-ditch drainage system
paddy growth period
changes of nitrogen and phosphorus
spatiotemporal distribution
