氮磷对牛蹄豆幼苗生长及光合特性的影响

对引进树种牛蹄豆幼苗生长和光合特征中的氮磷响应进行了研究。结果表明牛蹄豆对氮磷的适应性均较强,即随供氮量的增加,牛蹄豆的根冠比、根生物量比显著降低;在较大的氮范围内,牛蹄豆的总生物量都随供氮量的增加而显著增加,超过0.1g/kg土则显著下降;随供磷量的增加,牛蹄豆的根冠比、根生物量比降低,总生物量显著增加;无论在供氮量增加还是在供磷量增加的情况下,牛蹄豆的比叶面积增加,株高、叶氮、叶磷、净光合速率显著增加。

Effects of Nitrogen and Phosphorus on Growth and Photosynthesis of Pithecellobium dulce Seedlings

Effects of nitrogen and phosphorus on growth and photosynthesis of Pithecellobium dulce(an introduced species) seedlings were studied.The results showed that P.dulce was able to acclimate to a wide range of nitrogen and phosphorus environment.With an increase in nitrogen level,the ratio of root mass to total mass and root mass to overground mass of the seedlings significantly decreased.Under a wide range of nitrogen level,their total biomass significantly increased,but decreased significantly at over 0.1g·kg-1soil nitrogen level.With an increase in phosphorus level,the ratio of root mass to total mass and root mass to overground mass of the seedlings decreased,but the total biomass significantly increased.No matter with an increase in nitrogen level or with an increase in phosphorus level,the specific leaf area(SLA) of the seedlings increased and their height,leaf nitrogen content,leaf phosphorus content,net photosynthetic rate also significantly increased.