不同施肥期沾化冬枣对^(15)N的吸收、分配及利用特性

Characteristics of Absorption, Distribution and Utilization of ‘Zhanhua Dongzao’ Jujube to ^(15)N in Different Fertilizer Application Stages

盆栽条件下利用15N示踪技术,研究不同时期施15N-尿素,对沾化冬枣15N的吸收利用及分配特性的影响。结果表明:生长季前期(萌芽前和花前)施用15N-尿素,经根系吸收后,15N优先分配到贮藏器官(包括主干、多年生枝和粗根)中,然后外运用于树体新生器官(包括枣吊及其叶片、新生营养枝、细根及果实)的形成,果实采收后15N开始向贮藏器官回流;果实硬核期15N直接用于树体营养生长和生殖生长,而不是先贮藏再利用;果实速长期15N优先向贮藏器官中积累;萌芽前施15N在树体内的运转规律符合落叶果树贮藏N营养分配规律,优先转运到生长中心。随着施肥期的后延,植株对15N-尿素的当季利用率逐渐下降。

The technique of isotope  15 N-labelled urea is used to study the characteristics of  15 N absorption, partition and translocation of‘Zhanhua Dongzao’jujube in different fertilizer application stages under the potted condition. The results showed that: Fertilized before sprout and before full-bloom,  15 N absorbed by the root was distributed preferentially to the storage organs (including the trunk, the perennial spurs and the large root),then was transported to the use of the new organs construction (including the deciduous spur and its leaf, the neonatal branches, the fine root and the fruit), and after fruit harvest  15 N was started to circumfluent to storage organs again. Fertilized during fruit core-hardening,  15 N was transported not directly to the storage organs, but to the reproductive organs and nutritional organs. And fertilized during fruit rapid growth,  15 N was distributed firstly and preferentially to the storage organs. When  15 N-urea was fertilized before sprout in jujube trees the rule that  15 N was translocated firstly to the growth center was in accordance with storage N distribution rule of deciduous fruit trees. And with the delay of  15 N-urea application stage,  15 N utilization rate of the plant decreased gradually.