通过同位素示踪技术研究了不同时期幼龄橡胶树对15N标记尿素的吸收和分配特性.结果表明:顶蓬嫩叶和成熟叶从氮肥中吸收分配到的15N的量,对该器官全氮量的贡献率(Ndff值),随着施肥时间的延长总体均呈增加趋势;同一采样时间里顶蓬嫩叶Ndff值均大于成熟叶.落叶前后氮素在橡胶树各器官中分配差异显著.落叶前期橡胶树吸收的氮素主要分配在叶片中;落叶期橡胶树吸收的氮素则主要分配在主茎中.%Absorption and distribution of 15N-labelled urea in different parts of young rubber tree were studied by using 15N trace technique. Results showed that Ndff of newly developed top leaves and mature leaves both increased with the extended application time, and Ndff of newly developed top leaves was higher than that of mature leaves at the same sampling time.There was significant difference in the nitrogen distribution of various organs of rubber tree between pre-defoliation period and defoliation period. Fertilizer N absorbed by rubber tree was mainly distributed into leaves in pre-defoliation period and transported from the leaves to the trunk before defoliation.
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