宁夏黄灌区稻秆还田对硝态氮流失量的影响.pdf

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1、农业环境科学学报2011,30(4)：697—703JournalofAgro—EnvironmentScience宁夏黄灌区稻秆还田对硝态氮流失量的影响王永生，黄剑，杨世琦(中国农业科学院农业环境与可持续发展研究所；农业部农业环境与气候变化重点开放实验室，北京100081)摘要：为控制稻田土壤硝态氮流失，对宁夏黄灌区稻田设置不同量秸秆还田处理：常规施肥不还田(CK)、常规施肥条件下稻秆分别半量(T。)与全量(T2)还田，采用树脂芯法测定了稻秆还田10、20、30am土层硝态氮淋失量。结果表明，稻秆还田可以有效减少30Cm处硝态氮淋失量，减少比例在5．5％左右。从生育期内来看，前期流失量大

2、于后期，但在后期120am土层渗滤液中硝态氮含量在10mg·L。1以下，对地下水污染没有威胁。稻秆还田条件下，前期土壤硝态氮含量较低，减少了硝态氮淋失的可能性，后期N素得到释放而促进了水稻的生殖生长，产量得到增加。因此，稻秆还田可以作为源头控制稻田硝态氮流失的较好措施加以推广。关键词：硝态氮；淋失量；秸秆还田；树脂芯中图分类号：$181文献标志码：A文章编号：1672—2043(2011)04—0697—07TheInfluenceofRiceStrawReturningontheLeachingLossesoftheNitrateNitrogeninNingxiaIrrigationDi

3、strict，ChinaWANGYong-sheng，HUANGJian，YANGShi-qi木(InstituteofEnvironmentandSustainableDevelopmentinAgriculture，ChineseAcademyofAgriculturalSciencesKeyLaboratoryofAgro—EnvironmentandClimateChange，MinistryofAgricultural，Beijing100081，China)Abstract：NingxiaIrrigationDistrictistherepresentativeirrigati

4、onfarmingregionintheupperstreamareaoftheYellowRiver．Thepaddy-uplandrotationisstillthetypicalagriculturalmodelinthisirrigationdistrict．Thecrudefarmingmethodsareusedinthepaddyplanting，suchuncontrolled‘‘‘and‘fertilization．thereforethere‘highaccumulationoftheresidual‘soilaftertheasuncontrolledirrigati

5、onandexcessivetertilizationtheretorethereISahighaccumulationoItheresidualnitratenitrogeninsoilerthe，harvest．AfiledexperimentwasconductedinpaddyofNingxiaYellowRiverIrrigationDistrictwiththreetreatmentsincludingnormalfertil-ization(CK)，halfreturning(T1)andtotalreturning(T2)，respectively，onthebasisof

6、thenormalfertilization．Theleachinglossesofnitrateni-trogeninthedepthof10，20，30amwasmeasuredbythemethodofresincore．Theresultshowedthattheleachinglossesof30amwerere-ducedeffectivelybystrawreturning．thedecreaseratioofleachinglosseswasabout5．5％．Theleachinglossesofnitratenitrogenwasbiggerinpreviousthan

7、laterduringthegrowthperiod．Theconcentrationofthenitratenitrogeninthe120amsoilpercolatewasunder10mg。L一1inthelaterperiod，therewasnothreattothegroundwaterpollution．Theresultsindicatedthatricestrawreturningcouldreduc