【摘要】 定量分析不同水肥管理下设施菜地的氮素损失途径及氮素利用效率,可为合理制订菜地水肥管理措施提供科学依据。2009年在北京市顺义区设施番茄大棚设置了6种水肥管理模式:(1)传统施肥+传统畦灌(N1F1);(2)优化施肥+优化畦灌(N2F2);(3)减量施肥+优化畦灌(N3F2);(4)传统施肥+传统滴灌(N1D1);(5)优化施肥+优化滴灌(N2D2);(6)减量施肥+优化滴灌(N3D2)。利用田间观测数据对EU-Rotate_N模型进行了校验,并计算了各水肥管理下设施菜地的氮素淋失、气体损失和氮素利用效率。结果表明,各处理的土壤氮素淋失量占施肥总量的1%~9%,气体损失占施肥总量的5%~14%,各处理氮素淋失表现为N1F1>N3F2≈N2F2>N1D1>N2D2>N3D2。滴灌处理的淋失量比对应畦灌处理减少了72%~87%,气体损失量比畦灌处理平均降低了40%,其氮素利用效率比对应畦灌处理提高32%~36%。在保证蔬菜产量影响不大的情况下,优化施肥和滴灌均能有效地降低氮素淋失和气体损失,提高氮素利用效率。更多还原

【Abstract】 Optimal applications of water and fertilizers are important for maintaining yield and reducing environmental pollution in green-house vegetable production. An experiment was conducted to examine nitrogen(N)loss pathways and nitrogen use efficiency(NUE)under different water and fertilizer managements in a tomato-growing greenhouse located in Shunyi, Beijing from August 2009 to January2010. Six different water and fertilizer combinations were designed, including(i)traditional fertilization + traditional irrigation(N1F1)(,ii)optimal fertilization +optimal irrigation(N2F2)(,iii)reduced fertilizer + optimal irrigation(N3F2),(iv)traditional fertilization +conven-tional drip irrigation(N1D1)(,v)the optimal fertilization + optimal drip irrigation(N2D2)and(vi)reduced fertilizer + optimal drip irrigation(N3D2). We used the field observed dataset to calibrate and validate the EU-Rotate N model, and calculated N leaching, gaseous N loss and NUE. The results showed that the amounts of N leaching and gaseous N loss under different treatments accounted for 1%~9% and 5%~14% of total applied N, respectively. Nitrogen leaching for all treatments was in order:N1F1>N3F2≈ N2F2>N1D1>N2D2>N3D2. Compared with the corresponding furrow treatments, N leaching under drip treatments was reduced by 72%~87%, gaseous N loss decreased by about 40%, and the NUE increased by 32%~36%. Therefore, optimal fertilization and drip irrigation combination practices could significantly reduce N leaching and gaseous N loss and increase the NUE without decreasing tomato yields.更多还原