滇池柴河流域蔬菜地土壤施用控释尿素与普通尿素的氮损失比较  

Comparison of Nitrogen Loss Between Controlled Release Urea and Common Urea in Vegetable Soils at Chaihe Catchment of Dianchi Lake

作　　者：朱晓琦[1] 胡正义[1] 王惠惠[1] 周国慧[1] 刘小宁[1] 

机构地区：[1]中国科学院大学资源与环境学院,北京100049

出　　处：《中国农业科技导报》2014年第6期109-116,共8页Journal of Agricultural Science and Technology

基　　金：国家水体污染控制与治理科技重大专项(2012ZX07102-003)资助

摘　　要：在滇池柴河流域,蔬菜地施用的氮肥通过径流、淋溶和氨挥发等途径向水体迁移,对周围水体质量有较大影响。通过盆栽试验比较了控释尿素(3个氮水平:0 mg N/kg土、280 mg N/kg土和320 mg N/kg土)与普通尿素(4个氮水平:0 mg N/kg土、280 mg N/kg土、320 mg N/kg土和400 mg N/kg土)施用在柴河流域土壤所表现出的肥料氨挥发和氮淋失特征。结果表明,两种氮肥所有施氮水平处理的氮淋溶量都显著大于氨挥发量。在两种施氮水平下(320 mg N/kg土和280 mg N/kg土),施用普通尿素产生的氨挥发量分别占施氮量的3.64%和3.57%,而施用控释尿素产生的氨挥发量分别占施氮量的3.64%和2.78%;施用普通尿素产生的氮淋失量分别占施氮量的14.38%(其中硝态氮占85.34%)和14.46%(其中硝态氮占95.70%),施用控释尿素产生的氮淋溶量分别占施氮量11.60%(其中硝态氮占91.05%)和8.37%(其中硝态氮占96.84%)。硝态氮淋溶可能是柴河流域蔬菜地肥料氮素向水体迁移的主要途径。随着施氮量的减少,控释尿素的氮淋失量显著下降,而普通尿素的氮淋失量差异不显著。相同施氮水平下,普通尿素氮淋失量显著大于控释尿素。由此可见,控释尿素主要通过减少氮淋溶途径来减少氮损失。减量施氮结合控释尿素的施用对控制该地区氮肥施用对水体污染具有实际的指导意义。At Chaihe catchment of Dianchi Lake,application of fertilizer in vegetable soils exerted negative influence on water body due to discharge of nitrogen（N） from vegetable land via nitrogen leaching,runoff and ammonia volatilization and subsequent deposition.Pot experiment was carried out to compare the loss of nitrogen via leaching and ammonia volatilization when applying 2 nitrogen sources（CU：common urea and CRU：controlled release urea）with different rates（0 mg N / kg soil,280 mg N / kg soil,320 mg N / kg soil and 400 mg N / kg soil） of N supply.The results showed that N loss in soil was significantly greater via leaching than via ammonia volatilization irrespective of N sources and application rates.There was no significant difference in ammonia volatilization between CU and CRU,and the cumulative ammonia volatilization in treatments of 320 mg N / kg soil and 280 mg N / kg soil accounted for 3.64% and 3.57% in supplied CU respectively,while accounted for 3.64% and 2.78% in supplied CRU respectively.However,the leaching loss of N was significantly greater in CU treatment than that in CRU treatment,and the leaching loss of N in treatments of 320 mg N / kg soil and 280 mg N / kg soil accounted for 14.38% and 14.46% in supplied CU respectively,while accounted for 11.60% and 8.37% in supplied CRU respectively.Theleaching loss of N decreased with reduced application rate of supplied CRU.However,no obvious difference of N leaching loss among rates of CRU supplied was found.The decrease of nitrogen loss in supplied CRU is mainly attributed to the decrease of N leaching,rather than ammonia volatilization.Therefore,the NO3--N leaching may be the main pathway for transportation of N from vegetable soils to water body in Chaihe catchment.The lower application rate of CRU might have a practical influence on reducing risk of eutrophication in Dianchi Lake.

关 键 词：普通尿素 控释尿素 氨挥发 氮淋溶 柴河流域 

分 类 号：X522[环境科学与工程—环境工程]