不同氮素形态对桉树幼苗生长及某些生理特性的影响

Effects of Different Nitrogen Forms on the Growth and Physiological Characteristics of Eucalyptus Seedlings

[目的]为明确桉树幼苗的氮素营养特性,进一步为桉树幼苗的栽培管理提供科学的理论依据。[方法]采用水培的方法研究不同氮素形态对尾赤桉和巨尾桉幼苗生长及某些生理指标的影响。[结果]在相同氮素浓度处理下,桉树幼苗对硝态氮的吸收量显著大于对铵态氮的吸收量;在铵态氮处理下,尾赤桉对铵态氮的吸收量显著高于巨尾桉。桉树叶片的叶绿素含量随着氮素处理浓度的升高而升高;但是过高的氮素处理,叶绿素含量则出现下降的趋势。铵态氮更有利于尾赤桉幼苗的高生长,其高生长增量显著大于巨尾桉16号;而硝态氮对2种桉树幼苗高生长的影响没有显著差异。[结论]不同桉树品种的氮素营养特性不同。

[ Objective] The research aimed to study the nitrogen nutrition characteristics in eucalyptus seedlings and provide theoretical basis for eucalyptus seedlings cultivation management. [ Methods] The effect of nitrogen forms on the growth and physiological characteristics of eucalyptus seedlings were studied with the method of water culture. [ Results] In the same concentration of nitrogen treatment, the amount of nitrate nitrogen absorbed by eucalyptus seedlings was much higher than ammonium nitrogen. In the ammonium nitrogen treatments, the amount of ammonium nitrogen absorbed by E. urophylla × E. camaldulensis was significantly higher than by E. grandis × E. urophylla. The results also showed that the chlorophyll content of leaves in eucalyptus seedlings increased with the concentration of nitrogen, but it showed a decreasing tendency in overhigh nitrogen concentration. In the ammonium nitrogen treatments, the height increment of E. urophylla × E. camaldulensis was significantly greater than that of E. grandis × E. urophylla ; but in the nitrate nitrogen treatments, the height increment between two eucalyptus species has no significant difference. [ Conclusion] Different eucalyptus species showed different nitrogen nutrition characteristics.