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1、第21卷第4期环境科学学报Vol.21,No.42001年7月ACTASCIENTIAECIRCUMSTANTIAEJuly,2001文章编号:025322468(2001)20420475206中图分类号:X592文献标识码:A水稻田面水氮素的动态特征、模式表征及排水流失研究张志剑,董亮,朱荫湄(浙江大学环境与资源学院,杭州310029)摘要:采用具有独立排灌系统的田间试验研究了水稻田面水氮素的动态特征、模式表征及田间排水氮素流失.施用尿素后,田面水氨氮、总氮浓度迅速增加;随时间的推移,田面水氮素浓度下降较快.施氮后第3—4天,田面水氨氮P总氮比为0141—0191,随
2、时间的推移,氨氮P总氮比呈下降趋势.田面水总氮、氨氮浓度随时间动态下降的最佳拟合模式为指数、对数或乘幂2型.在控水灌溉下的水稻田,两次田间排水合计总氮流失负荷分别为81993—291131kgPhm,氮肥表观流失率随施氮量提高而逐渐下降.施氮后一周是防止水稻田面水氨氮、总氮大量流失的关键时期.关键词:水稻田;氮素;动态特征;模式表征;流失Thedynamiccharacteristicsandmodelingofnitrogeninpaddyfieldsur2facewaterandnitrogenlossfromfielddrainageZHANGZhijian,DON
3、GLiang,ZHUYinmei(CollegeofEnvironmentandNaturalResources,ZhejingUniversity,Hangzhou310029)Abstract:Afieldcasestudywithindependentirrigationsystemwasconductedtoelucidatethedynamiccharacteristics,modelingofnitrogen(N)insurfacewaterofpaddyfieldandNlossfromdrainage.Theresultsoffieldexperiment
4、showedthatureaapplicationwithinthreetimes+sharplyincreasedtheconcentrationsofammonianitrogen(NH42N)andtotalnitrogen(T2N)infieldsurfacewaterandbothsubsequentlyde2+clinedasthetimefollowed.OnthethirdtofourthdayafterNapplicationtherateofNH42NPT2Ninsurfacewaterwas0.41—0.91,andsl2oweddownasthet
5、imefollowed.QuantitativemodelswithbestcoefficientforT2NandNH42NconcentrationsinthefieldsurfacewaterafterN2fertilizerapplicationwereexponentialandlogarithmicorlogarithm.TotalNlosswithintwodrainagesreached8.993kgNPhm(N2Ⅰ),16.0132222kgNPhm(N2Ⅱ),24.969kgNPhm(N2Ⅲ),26.744kgNPhm(N2Ⅳ)and29.131kgN
6、Phm(N2Ⅴ)respectively.ItwasclearthatNap2parentlossratiowasreducedastheNapplicatedlevelincreased.TheperiodwithinaweekafterNapplicationwasdefinedasthekeytimetocontrolmassiveNlossfromfloodedpaddyfield.TocontrolNnonpointpollutionfrompaddyfield,furtherresearchmustbefocusedonthemin2imizationofNl
7、ossfrompaddyfielddrainageandthebestNmanagementfornativericeproduction.Keywords:Paddyfield;nitrogen;dynamiccharacteristic;modeling;loss[1,2]水体生态环境的恶化很大程度上归因于农业面源氮磷等营养型污染物.农田氮素的损失或流失是农业氮素面源的主要贡献者.已报道的农业氮素面源研究较多地针对氮肥的一种[3,4]+或几种周转产物而进行,如田间土壤或排水途径下的硝氮(NO32N)淋溶流失、氨氮(NH42
