养殖污水直灌对稻田土壤氮、磷积累与垂直迁移的影响

养殖污水直灌对稻田土壤氮、磷积累与垂直迁移的影响*章明奎**摇AHMEDElgodah摇鲍陈燕(浙江大学环境与资源学院,杭州310058)摘摇要摇尽管国内外对养殖污水处理已提出了一系列的工艺技术,但因经济原因养殖污水直接灌溉农田在我国农村地区仍较为常见.为了解长期畜禽养殖污水直灌对稻田土壤质量的影响,在浙江省绍兴市柯桥区选择了养殖污水直灌不同年限(0、4、7、13年)的稻田,比较研究了养殖污水直接灌溉对稻田土壤不同深度土层中各形态氮和磷含量的影响,探讨了长期养殖污水灌溉对氮、磷在土壤剖面中垂直迁移的影响.结果表明:长期养殖污水直接灌溉可显著提高稻田土壤中氮和磷的积累,积累量随灌溉年限的增长而增加,其中磷素的增幅高于氮素.养殖污水灌溉4、7和13年后,土壤表层中全P和全N分别比对照增加了43.6%、95.2%、148郾4%和7.7%、17.0%、28.4%.土壤氮素的变化为NH4+鄄N、NO3-鄄N>酸解有机氮>非酸解有机氮;土壤有效磷的变化明显大于全磷.长期养殖污水灌溉可促进氮、磷在土壤剖面中的垂直迁移,增加对地下水的污染风险.关键词摇养殖污水摇灌溉摇水稻土摇氮形态摇磷形态摇环境风险文章编号摇1001-9332(2014)12-3600-09摇中图分类号摇S141.3;X53摇文献标识码摇AEffectsofirrigationofuntreatedlivestockfarmwastewateronaccumulationandverticalmig鄄rationofnitrogenandphosphorusinpaddysoil.ZHANGMing鄄kui,AHMEDElgodah,BAOChen鄄yan(CollegeofEnvironmentalandResourceSciences,ZhejiangUniversity,Hangzhou310029,China).鄄Chin.J.Appl.Ecol.,2014,25(12):3600-3608.Abstract:AlthoughaseriesofprocesstechniquesfortreatingwastewaterfromlivestockandpoultrybreedinghavebeendevelopedinChinaandoverseas,itisstillcommoninChina爷sruralareasforutilizationoftheuntreatedwastewatertoirrigatefarmlanddirectlybecauseofeconomicreasons.Theimpactofuntreatedwastewaterirrigationonaccumulationandverticalmigrationofnitrogenandphosphorusinpaddysoilisconcerned.Consequently,fourrepresentativepaddyfieldswithdifferenthistoriesoflivestockfarmwastewaterirrigation(0,4,7,13years)wereselectedforcollectingpro鄄filesoilsamplestostudytheeffectsoflong鄄termirrigationofuntreatedlivestockfarmwastewateronvariousformsofnitrogenandphosphorusinthesoilsatdifferentverticaldepths.Ascomparedwithcontrolfieldwithoutanyirrigationofwastewater,long鄄termirrigationofuntreatedlivestockfarmwastewatersignificantlyincreasedtheaccumulationofNandPinthesoilswithincreasingtheirriga鄄tionyear,andtheincrementoftotalPinthesoilwasgreaterthanthatoftotalN.TotalPcontentinsurfacesoilfromfieldswith4,7,and13yearsirrigationwasincreasedby43.6%,95.2%,and148.4%,whiletotalNincreasedby7.6%,16.9%,and28.4%,respectively.DifferentformsofsoilNwereincreasedinorderofNH4+鄄N,NO3-鄄N>acidhydrolyza