【摘要】 利用田间小区试验,研究了无机肥配施不同用量有机肥对菜地土壤氮素径流流失的影响。结果表明,施肥显著增加菜地土壤氮素径流流失量。单施无机肥处理总氮、硝态氮和铵态氮流失量均最高,分别为4.20,1.22,2.30kg/hm2。配施有机肥可降低不同形态氮流失量,且随有机肥配施量增加而显著降低。配施高量有机肥处理总氮、硝态氮和铵态氮流失量相比单施无机肥处理分别降低了53.4%,58.2%和56.0%。不同处理下,矿质态氮(硝态氮+铵态氮)流失量占总氮流失量的76.8%～84.0%,矿质态氮是土壤氮径流输出的主要形态。试验期间,不同处理硝态氮浓度均未超过地表水环境质量标准限值,铵态氮和总氮浓度相对较高,存在一定的污染风险。氮肥追施一定程度上易增加其施用几天内降雨径流液的硝态氮浓度。更多还原

【Abstract】 A field plot experiment was conducted to study the effects of combined application of organic and inorganic fertilizer on soil nitrogen runoff in vegetable field.The results showed that fertilizer application increased the nitrogen loss via runoff.The highest losses of total nitrogen,nitrate nitrogen and ammonium nitrogen were 4.20,1.22,2.30 kg/hm2,respectively,as treated by inorganic fertilizer alone.The nitrogen loss decreased significantly with the increased combined application of organic and inorganic fertilizer.For treatment of higher organic matter application rate,the losses of total nitrogen,nitrate nitrogen and ammonium nitrogen were reduced by 54.3%,58.2% and 56.0%,respectively,as compared with the inorganic fertilizer treatment.The runoff loss of mineral nitrogen(nitrate nitrogen plus ammonium nitrogen) was 76.8%~84.0% of that of total nitrogen in all treatments.The results indicated that mineral nitrogen was the main form of soil nitrogen via runoff in a field.During the experiment,nitrate nitrogen concentration did not exceed the standard of surface water environmental quality while the ammonium nitrogen and total nitrogen had risk of pollution to water in some extent due to the higher content in runoff water in different treatment.After the several days of nitrogen fertilizer topdressing,the concentration of nitrate nitrogen could increase in runoff water.更多还原