夏玉米各器官氮素积累与分配动态及其对氮肥的响应  

Dynamic Responses of Nitrogen Accumulation and Remobilization in Summer Maize Organs to Nitrogen Fertilizer

作　　者：张经廷[1] 刘云鹏[1] 李旭辉[1] 梁效贵[1] 周丽丽[1] 周顺利[1] 

机构地区：[1]农业部农作制度重点开放实验室/中国农业大学农学与生物技术学院,北京100193

出　　处：《作物学报》2013年第3期506-514,共9页Acta Agronomica Sinica

基　　金：教育部新世纪优秀人才支持计划(NETC-10-0790);国家自然科学基金项目(31071367);国家公益性行业(农业)科研专项(200903007;201203031)资助

摘　　要：为探明夏玉米各器官氮素积累与分配动态及其对氮肥的响应,以郑单958为材料,设置5个施氮水平进行了连续2年的大田定位研究。结果表明,除籽粒外各器官的氮素积累进程都呈单峰曲线,茎鞘在吐丝期达到峰值,而叶片、苞叶和穗轴则到吐丝后12d左右达到峰值,之后逐渐下降;籽粒和整株的氮素积累随生育进程持续增加,成熟期最高。与其他器官相比,叶片对氮素供给更敏感,氮胁迫使叶片氮素积累高峰提前,促进氮素提前向外转运,导致其率先衰老。施氮能提高各器官在各生育时期的氮素积累量和积累速率,但不改变氮素积累变化趋势。总体上,施氮量180kg Nhm-2可满足夏玉米对氮素的需求,获得较高的产量。以各器官氮素积累最大值与成熟期的差值计算,各处理再转运氮素对籽粒的贡献率均表现为叶片>茎鞘>穗轴>苞叶,各器官再转运氮素对籽粒贡献率之和平均为53.3%,其中苞叶和穗轴占12.3%,也是籽粒中氮素来源的重要组成部分。A successive two years＇ field experiment with five N application rates was conducted using hybrid Zhengdan 958. The results showed that the process of N accumulation in all organs except grain conformed to a unimodal curve in the whole life cy- cle. The N accumulation in blade, bract, and cob reached the peak at around 12 days after silking, and that in stem and sheath at silking stage and then decreased gradually. The N accumulation in grain and the whole plant continuously increased, and the maximum value appeared at maturity. Compared with other organs, blade was more sensitive to N supply and N deficit stress made the N accumulation peak in advance, accelerated blade N remobilization and promoted senescence of blade. N supply sig- nificantly improved N accumulation amount and N accumulation rate in all organs at various stages, but did not change the trend of N accumulation. On the whole, the demands of maize organs for N could be met at the N application rate of 180 kg N ha-1, and a higher grain yield also achieved. According to the maximum value of accumulated N in organs, the contribution of remobilized N from maize organs to grain showed a trend of blade 〉 stem and sheath 〉 cob 〉 bract, and the mean total contribution rate was 53.3%, of which cob and bract accounted for 12.3%, showing an essential part for grain N, too.

关 键 词：夏玉米 器官 氮肥水平 氮素的积累 分配与再分配 

分 类 号：S513[农业科学—作物学]