不同水肥管理下设施黄瓜地氮素损失及水氮利用效率模拟分析

【目的】利用模型定量分析不同水肥管理对设施菜地氮素损失及水氮利用效率的影响，为设施菜地合理水肥管理措施的制定提供理论指导。【方法】2010—2011年在山东寿光设施大棚设置了4种水肥管理模式：对照+畦灌（CK）、传统施肥+畦灌（FP）、优化施肥+畦灌（OPT）和传统施肥+滴灌（RI）。利用EU-Rotate_N模型模拟了两个生长季（春夏茬和秋冬茬）各处理下设施黄瓜地的产量、氮素淋失和气体损失等，并计算了水氮利用效率。【结果】两个生长季内滴灌处理（RI）比畦灌处理（CK、FP和OPT）节水约60%，且灌溉水利用效率提高了2倍多。在各施肥处理中，春夏茬和秋冬茬黄瓜的氮素气体损失分别占施氮量的16%—19%和6%—11%，氮素淋失量分别占施氮量的14%—57%和20%—55%，其中OPT和RI处理的氮素淋失量比FP处理分别减少了19%—31%和63%—76%。OPT处理两茬黄瓜的氮素利用效率比FP处理分别提高了3%和7%，而RI处理的氮素利用效率比FP处理分别提高了41%和44%。【结论】氮素淋失是设施菜地氮素损失的主要途径，滴灌和优化施肥均能有效地减少菜地土壤硝态氮的淋失，提高氮素利用效率。

Simulation and Analysis of Nitrogen Loss, Water and Nitrogen Use Efficiencies of Greenhouse Cucumber Under Different Water and Fertilizer Managements

【Objective】 The study was to quantify the nitrogen (N) loss, and water and nitrogen use efficiencies (WUE, NUE) of greenhouse vegetable under different water and fertilizer managements using the EU-Rotate_N model, and to provide some basic suggestions on greenhouse vegetable cultivation. 【Method】 A field experiment was conducted in a cucumber greenhouse located in Shouguang city, Shandong Province, from 2010 to 2011. Four different water and fertilizer practices were designed, including no fertilizer + furrow irrigation (CK), conventional fertilization +furrow irrigation (farmer’s practice, FP), optimal fertilization + furrow irrigation (OPT), and conventional fertilization + drip irrigation (RI). The EU-Rotate_N model was used to simulate the yield, nitrate leaching, and gaseous N loss, during spring-summer (SS) and autumn-winter( AW) seasons. WUEs and NUEs of all treatments were also calculated. 【Result】 The results showed that irrigation water use efficiencies under drip irrigation (RI) increased by over twice compared with furrow irrigation treatments (CK, FP and OPT) with saving 60% of irrigation input in both growing seasons. For all fertilization treatments, the amount of gaseous N loss accounted for 16%-19% and 6%-11% of total N input in SS and AW seasons, respectively. The amounts of nitrate leaching accounted for 14%-57% and 20%-55% of total N application in SS and AW seasons, respectively. Compared with FP treatment, the amount of nitrate leaching in OPT and RI treatments reduced by 19%-31% and 63%-76%, respectively. Meanwhile, the NUE in OPT treatment increased by 3% and 7%, and the NUE in RI treatment increased by 41% and 44% in SS and AW seasons, respectively. 【Conclusion】 Nitrate leaching is a major component of N loss in greenhouse vegetable production in Shouguang County. Both optimal fertilization and drip irrigation practices could reduce the nitrate leaching and increase the NUE.