玉米秸秆还田条件下麦田氮素运转和籽粒产量对氮肥的响应

摘要

To provide the theoretical basis for rational nitrogen application in the high yield region of North Henan Province,the field experiments were carried out during 2011-2013 using Zhoumai 18 and Jimai 22 as materials.Under the condition of corn straw returning,7 nitrogen fertilizer levels were arranged:N0 (no nitrogen application in whole growth stage),and N1,N2,N3,N4,N5 and N6,of which 0,60,100,140,180 and 210 kg/ha nitrogen were topdressed respectively at jointing stage under the condition of 120 kg/ha nitrogen as basic fertilizer.The dynamic change of nitrogen content in soil and wheat plants,the amount of nitrogen absorption in wheat plants,the nitrogen utilization efficiency in wheat and soil system and the grain yield under different fertilizer treatments were analyzed.The results showed that nitrogen accumulation of wheat plants and grain yield changed as a single peak curve with the increase of topdressing amount.For the treatments N3 and N4,nitrogen accumulation in Zhoumai 18 plants was higher,and the grain yields was higher simultaneously,while Jimai 22 showed higher nitrogen accumulation and higher grain yields in N1 and N2 treatments.With the adding of nitrogen amount,nitrogen loss in wheat and soil system tended to rise first and then fall.Nitrogen partial factor productivity (NPFP) and nitrogen agronomic efficiency could be improved significantly with straw returning and proper nitrogen fertilizer application,but they tended to be lower with the continuous increase of nitrogen.In consideration of both nitrogen fertilizer efficiency and grain yield,the appropriate nitrogen application of Zhoumai 18 and Jimai 22 was 220-260 kg/ha and 120-180kg/ha respectively under the condition of straw returning in wheat and corn double cropping area.%为给秸秆全部还田条件下豫北麦玉两熟高产地区冬小麦合理施用氮肥提供理论依据,以周麦18和济麦22为试材,于2011-2013年研究了不同施氮处理(小麦全生育期不施氮肥,及底施纯氮120 kg/hm2基础上拔节期分别追施0,60,100,140,180,210 kg/hm2)下麦田土壤和植株氮素含量的动态变化,分析了不同追氮量对植株氮素吸收、麦田氮肥利用率和籽粒产量的影响.结果表明,小麦檀株氮素吸收积累和籽粒产量随施氮量的增加呈单峰曲线变化,周麦18和济麦22分别在220,260 kg/hm2和120,180 kg/hm2施氮量下植株氮素吸收积累达到峰值,籽粒产量较高.麦田氮流失量随施氮量增加呈先升后降变化趋势.秸秆还田配施适量氮肥能够显著提高氮肥偏生产力、氮肥农学利用率;随着施氮量的持续增加氮肥偏生产力、氮肥农学利用率显著降低.综合来看,玉米秸秆还田条件下兼顾氮肥效率和籽粒产量,豫北麦玉两熟区周麦18适宜的氮肥配施量为220 ～ 260 kg/hm2,种植济麦22适宜的氮肥配施量为120～180 kg/hm2.