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期 刊 ：植物研究 2015年 35卷 3期 页码：391-396

关键词：白桦；裸根苗；指数施肥；生长动态；光合作用；

Keywords:Betula platyphylla, bare-rooted seedlings, exponential fertilization, growth dynamic, biomass allocation,

摘 要 ：设定常规施肥（CF）、指数施肥（EF）和1.5倍指数施肥（EF1.5）3种施肥处理研究不同氮素施入方法和剂量对白桦1年生裸根苗生长（苗高、地径、生物量）动态、生物量分配、相对生长速率(RGR)和光合作用的影响。研究结果表明：（1）3种处理苗木生长前期苗高、地径和生物量均无显著差异，生长后期EF与EF1.5显著高于CF（P<0.05），EF与EF1.5间差异不显著（P>0.05）；（2）生长结束时，EF、EF1.5处理苗高分别比CF高18.2%和25%（P>0.05），地径分别比CF高11.2%和5.8%（P<0.05），单株生物量分别比CF高41.5%和25.4%（P<0.05）；（3）EF与EF1.5处理苗木的茎、叶、根生物量均显著高于CF，各处理间苗木的根冠比差异不显著（P>0.05）；（4）EF1.5处理和EF处理苗木苗高、地径及生物量相对生长速率（RGR）均显著高于CF处理（P<0.05），而EF1.5处理和EF处理间仅生物量相对生长速率达到显著水平，且EF>EF1.5（P<0.05）；（5）苗木生长高峰期，EF处理提高了苗木叶片的光合能力。EF处理苗木叶面积高于CF处理16.8%（P<0.05），叶绿素含量及光合速率较CF处理分别提高了4.5%（P>0.05）、5.0%（P>0.05）。EF、EF1.5处理常规施肥处理促进了苗木生长和生物量积累，二者促进效果类似，认为EF为最佳的施肥处理。

Abstract:We studied the growth(height, ground diameter, biomass) dynamic, biomass allocation, relative growth rate and leaf photosynthesis of Betula platyphylla bare-rooted seedlings under constant fertilization(CF), exponential fertilization(EF) and 1.5 exponential fertilization(EF1.5) regimes in one growing season. Dynamic of seedling height, ground diameter and biomass presented the same tendency, which barely showed difference in the early growing stage between three treatments, while both EF and EF1.5 were significantly higher than CF in the late growing period; however, EF and EF1.5 were not significantly different. At the end of the growing season, EF1.5 seedlings were the tallest, EF and EF1.5 seedlings were 18.2% and 25% taller than CF, respectively(P>0.05). EF seedlings owned the thickest ground diameter, EF and EF1.5 were 11.2% and 5.8% thicker than CF, respectively(P<0.05). The biomass sequence of each plant between three treatments was EF>EF1.5>CF, and EF and EF1.5 were 41.5% and 25.4% higher than CF, respectively(P<0.05). Stem biomass, leaf biomass and root biomass under EF and EF1.5 were both significantly higher than those under CF(P<0.05). Height, ground diameter and biomass RGR under EF and EF1.5 were both significantly higher than those under CF(P<0.05), and biomass RGR was EF>EF1.5(P<0.05). During the fast-growing periods of seedlings, EF treatment promoted seedling leaf photosynthetic characteristics. The seedling leaf area under EF treatment was 16.8% greater than that under CF treatment(P<0.05). Chlorophyll content and photosynthetic rate were increased by 4.5%(P>0.05) and 5.0%(P>0.05). EF and EF1.5 promoted seedling growth and biomass accumulation obviously than CF. EF saved a large amount of fertilizer than EF1.5, and promoted seedling growth similarly. Therefore, EF is the best treatment.

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