玉米秸秆还田配施氮肥对冬小麦产量和土壤硝态氮的影响

Effects of maize straw return with nitrogen fertilizer on winter wheat yield and nitrate nitrogen

【目的】研究关中地区玉米秸秆还田配施氮肥对冬小麦产量和土壤硝态氮的影响,为该区域秸秆还田条件下冬小麦氮肥管理优化提供科学依据。【方法】2012-2016年,采用裂区试验设计,主处理设玉米秸秆还田和秸秆不还田2个水平,副处理为5个不同施氮水平(0,84,168,252和336kg/hm2),共计10个处理,研究关中冬小麦-夏玉米轮作区玉米秸秆还田对后茬冬小麦产量及土壤硝态氮残留的影响。【结果】5年玉米秸秆还田定位试验结果表明,与玉米秸秆不还田处理相比,秸秆还田处理呈"低氮减产,高氮增产"的规律。2012-2016年,当施氮量分别高于153,187,99,146,115kg/hm2时,玉米秸秆还田处理冬小麦产量明显增加,最高增产率分别为7.2%,5.6%,9.5%,5.8%和7.5%。2012-2016年,与玉米秸秆不还田处理相比,玉米秸秆还田处理冬小麦收获后0~2m土层硝态氮累积量平均值分别增加25.4%,3.4%,13.5%,24.0%和1.7%。2012-2015年,与秸秆不还田处理相比,秸秆还田处理冬小麦播种前0~2m土层硝态氮累积量总体增加。不论玉米秸秆还田还是不还田,随着施氮量的增加,冬小麦收获后和播种前0~2m土层硝态氮累积量均逐渐增加。【结论】在关中地区,玉米秸秆还田配施一定量的氮肥可以提高冬小麦产量;玉米秸秆对土壤硝态氮具有十分明显的保持效果,可以为后茬作物提供养分。

【Objective】The effects of straw return with nitrogen fertilizer on winter wheat yield and nitrate nitrogen in winter wheat-summer maize rotation region in Guanzhong Plain were investigated to improve nitrogen application on field with straw return.【Method】Split plot design with ten treatments was carried out during 2012-2016.The main treatments included maize straw return to soil and maize straw removal,and the five subplots each had different N applications of 0,84,168,252 and 336 kg/hm2.【Result】Compared with maize straw removal,straw return treatment decreased yield with low nitrogen while increased yield with high nitrogen.From 2012 to 2016,when the amount of nitrogen fertilizer applied washigher than 153,187,99,146 and 115 kg/hm2,the yield with maize straw return was significantly increased by up to 7.2%,5.6%,9.5%,5.8% and 7.5%,respectively.Compared with maize straw removal,soil nitrate nitrogen accumulation in the depth of 0-2 m with maize straw return was increased by 25.4%,3.4%,13.5%,24.0% and 1.7%from 2012 to 2016.The soil nitrate nitrogen accumulation in the depth of0-2 m was increased by maize straw return from 2012 to 2015.With the increase of nitrogen fertilizer,the soil nitrate nitrogen accumulation in the layer of 0-2 mincreased after winter wheat harvest and before sowing,regardless of maize straw return.【Conclusion】A certain amount of nitrogen fertilizer with maize straw return increased the yield of winter wheat in Guanzhong Plain.Maize straw was helpful to preserve soil nitrate nitrogen and provide nutrients for crops.