控释尿素对小麦-玉米产量及土壤氮素的影响

利用田间试验研究了包膜控释尿素对小麦-玉米产量、氮素利用效率、土壤氮素积累及移动的影响。结果表明,与施用普通尿素比较,小麦-玉米周年施用包膜控释尿素,在肥料用量减少20%和40%情况下,小麦-玉米总产量分别是100%普通尿素处理的97.4%和97.7%;控释尿素施氮量为60%处理的肥料农艺利用率和偏生产力分别比普通尿素提高11.57%和54.14%。控释尿素施氮量为80%处理的肥料农艺利用率和偏生产力分别提高6.40%和22.09%。施用控释尿素显著增加了0-20 cm土层的碱解氮和0～40cm土层的硝态氮含量;60-100 cm土层中,控释氮肥处理土壤硝态氮含量与不施氮肥处理差异不显著,普通尿素处理小麦收获后60～80 cm土层、玉米收获后60～100 cm土壤硝态氮显著高于不施氮肥处理,肥料氮素下移明显。试验结果显示,施用控释尿素增加了耕层（0～20 cm）土壤的氮素积累,减少了氮素向土壤深层移动的数量,有利于减少施肥对环境的不利影响。

Effects of Controlled-release Urea on Wheat-corn′s Yield and Soil Nitrogen

The effects of controlled-release urea on wheat-corn′s yield,nitrogen use efficiency,soil nitrogen accumulation and movement were studied by field experiment.The results showed that the yield of wheat and corn were 97.4% and 97.7% respectively after applying con-trolled-release urea which quantity was decreased by 20% and 40% compared with that of general urea treatment.After applying controlled-release urea which amount was 60% of general urea,agronomic N use efficiency（ANUE）increased by 11.57% and partial factor productivity for applied fertilize（rPFP）increased by 54.14%.After applying controlled-release urea which amount was 80% of general urea,fertilizer a-gronomic utilization increased by 6.40% and partial factor productivity increased by 22.09%.Alkali-hydrolyzable（0～20 cm）nitrogen and soil nitrate（0～40 cm）were increased after applying controlled-release urea,soil nitrate（60～80 cm）had no significant difference between controlled-release urea and no nitrogen treatment,soil nitrate（60～80 cm,wheat block;60～100 cm,corn block）were increased compared with that of no nitrogen treatment,nitrogen moved obviously.Test results suggested that reducing controlled-release urea amount could in-crease nitrogen accumulation of upper soil,at the same time the amount of nitrogen which moved to soil depth was decreased.Therefore,re-ducing controlled-release urea amount was helpful to increasing the fertilizer′s adverse effect on environment.