论文部分内容阅读
江淮地区受梅雨影响,玉米苗期易发生渍害,如何通过合理运筹氮肥达到减灾效果值得研究。以夏玉米品种‘隆平206’为试验材料,研究不同氮肥运筹方式[氮肥全部基施(N1)、基肥70%+拔节肥30%(N2)、基肥50%+拔节肥50%(N3)和基肥30%+拔节肥50%+大喇叭口肥20%(N4)]对苗期受渍夏玉米根系形态和花后光合性能恢复的影响,以期为苗期受渍夏玉米合理施肥提供理论依据。结果表明,苗期渍水7 d抑制根系生长,根重、根长度、根表面积和根直径均显著降低,渍水对根系形态指标抑制效应表现为:根长度>根表面积>根直径。氮肥后移对渍水后根系生长有显著的补偿效应,氮肥后移量增加,根重、根长度和根表面积显著增加。渍水胁迫解除后18 d,N1-N4处理根长度较渍水前提高1.9~5.1倍,根表面积提高6.3~10.3倍,根直径提高0.7~1.0倍,氮肥后移对根系形态指标补偿生长效应强弱表现为:根表面积>根长度>根直径。渍水使群体叶面积系数降低9.3%~22.5%,氮肥后移可提高群体叶面积系数,较全部基施处理提高3.2%~20.7%。苗期渍水7 d显著降低灌浆期间穗位叶片的光合能力,净光合速率下降,灌浆中期和末期净光合速率分别下降16.1%和28.9%,灌浆后期光合能力下降幅度高于对照,非气孔限制是导致渍水胁迫下净光合速率下降的主要原因。渍水胁迫下,氮肥后移处理改善了穗位叶光合性能,光合能力优于氮肥前移处理。在苗期易导致渍害的地区适当减少基肥比例,后移氮素至拔节期和大喇叭口期,能够对受渍夏玉米起到较好的补偿生长效应。
Due to the influence of the rainy season in the Jianghuai region, the corn seedlings are prone to stain damage. How to achieve the disaster reduction effect through rational operation of nitrogen fertilizer is worthy of study. Taking the summer maize cultivar ’Longping 206’ as test material, the effects of different N application modes (N1, 70% + 30% jointing fertilizer, 50% basal fertilizer and 50% N3 + jointing fertilizer and The effect of 30% basal fertilizer + 50% jointing fertilizer + 20% (N4) of big bellmouth fertilizer on root morphology and post-anthesis photosynthetic property recovery of summer maize was studied in order to provide a theoretical basis for rational summer- . The results showed that waterlogging at seedling stage inhibited root growth for 7 d, root weight, root length, root surface area and root diameter decreased significantly. The inhibitory effect of waterlogging on root morphology was root length> root surface area> root diameter. After transplanting nitrogen fertilizer, there was a significant compensatory effect on root growth after waterlogging. The amount of transplanting nitrogen fertilizer increased, root weight, root length and root surface area increased significantly. The root length of N1-N4 increased by 1.9-5.1 times and the root surface area increased by 6.3-10.3 times and the root diameter increased by 0.7-1.0 times after the waterlogging stress was relieved. Nitrogen fertilization compensated the growth of root morphology Strength as follows: root surface area> root length> root diameter. Waterlogging decreased the leaf area coefficient of population by 9.3% -22.5%. After nitrogen fertilizer migration, the leaf area index increased by 3.2% ~ 20.7% than that of all basal treatments. Waterlogging at seedling stage significantly reduced the photosynthetic capacity, net photosynthetic rate and net photosynthetic rate of leaves at heading stage decreased by 16.1% and 28.9%, respectively, and the photosynthetic capacity at late filling stage decreased more than that of control and non-stomatal limitation Is the main reason for the decrease of net photosynthetic rate under waterlogging stress. Under waterlogging, photosynthetic capacity of spike leaf was improved after nitrogen fertilization, and photosynthetic capacity was better than that of nitrogen fertilizer. In the seedling susceptible to cause injury in the appropriate area to reduce the proportion of basal fertilizer, after the transfer of nitrogen to the jointing stage and the big bell mouth stage, the affected summer maize can play a good compensatory growth effect.