为探究不同施氮量对北疆滴灌超高产春玉米根系生长时空分布特征的影响,采用土壤剖面取样法大田研究了0、150、300、375和450 kg·hm-25个施氮水平对春玉米0～60 cm土层根系生长及产量的影响.结果表明,滴灌超高产春玉米根干重和根长度主要集中在0～20 cm土层,且生育期内表现为先升高而后降低变化,吐丝期达到峰值.增加施氮量显著提高各土层根干重密度和根长密度.大喇叭口期配合吐丝期施氮可明显延缓春玉米各土层根系衰老,特别是显著提高灌浆期20～60 cm土层根系活力.当施氮量在300 kg·hm-2左右时,春玉米根系长势相对较好,此时农学利用率为13.8 kg·kg-1,籽粒产量为17 117 kg·hm-2,较缺氮处理增产32.10％.若继续增加施氮量,各土层根系参数表现为降低变化趋势,且增产不显著,农学效率明显降低.综合考虑,该地区春玉米获取超高产的适宜施氮量可确定为拔节期结合大喇叭口期配合吐丝期施氮300 kg·hm-2.%To explore the effect of different nitrogen fertilizer on root distribution law of super-high-yield spring maize under drip irrigation.Five nitrogen levels(0,150,300,375,450 kg·hm-2)were used in the experiment to investigate the effect of root growth in 60 cm soil depth and yield of Spring Maize by soil profile sampling method.The results showed that,root dry weight and root length of super-high-yield spring maize were mainly concentrated in the 0～20 cm soil layer,and decreased after the first increase in the whole growth period,while the maximum was reached at the silking stage.Dry weight density and root length density of each layer significantly increased with ni-trogen increase.Applying nitrogen can delay root senescence of Spring Maize in different soil layers significantly during booting with silking stage,especially the root activity increased significantly during grain filling period in 20～60 cm soil layer.When the amount of nitrogen fertilizer was 300 kg·hm-2,the root growth of spring maize was better,and the agronomic efficiency was up to 13.8 kg·kg-1,meanwhile,the grain yield was 17 117 kg·hm-2,and the yield increased by 32.10％.When we continued to increase the amount of nitrogen fertilizer,the yield in-crease was not significant,and the root trait of each soil parameter showed a decrease trend of change.Comprehen-sive consideration,the suitable nitrogen amount would be 300 kg·hm-2at booting and silking stage,so that high yield can be achieved.
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