3种不同地下茎形态竹子的氮含量及积累特性

以浙江省典型的散生型高节竹（Phyllostachys prominens）、混生型苦竹（Pleioblastus amarus）和丛生型绿竹（Dendrocalamopsis oldhami）为研究对象，对其植株氮含量及其在不同器官间（叶、枝、秆）的分配进行研究。结果表明，3种竹子不同器官的氮含量均表现为叶 > 枝 > 秆，各器官氮含量均随着竹龄的增大而下降；3年生叶片氮含量绿竹显著大于高节竹、苦竹（P<0.05）；秆中氮含量表现为绿竹 > 苦竹 > 高节竹，其中2年生和3年生秆氮含量在竹种间的差异达显著性水平（P<0.05），绿竹和苦竹的1年生秆氮含量也显著大于高节竹（P<0.05）。不同竹种间枝条氮含量没有显著性差异（P>0.05）。不同竹种间氮素积累量表现为绿竹 > 苦竹 > 高节竹，其积累量分别为370.28、254.72和113.03 kg/hm²，而氮素利用效率高低则表现为高节竹 > 苦竹 > 绿竹，3种竹子每生产1 t干物质所需氮素为分别为6.37、6.53和7.96 kg。

Nitrogen Content and Accumulation Characteristics in Three Bamboo Species with Different Underground Stem-Root System

Nitrogen content and accumulation in different organs of bamboo including leaves, branches and culms was studied with the three typical bamboo species in Zhejiang Province, i.e., Phyllostachys prominens,Pleioblastus amarus and Dendrocalamopsis oldhami. The results showed that the nitrogen contents in the different organs of the three bamboo species could be ordered by leaves > branches > culms, and nitrogen content decreased with the age of bamboo. Nitrogen content in 3-year-old D. oldhami was significantly higher than that of Ph. prominens and P. amarus (P<0.05).Nitrogen content in culms were in the order of D. oldhami > P. amarus > Ph. prominens, and there were significant difference among 2-and 3-year-old bamboo culms of the three species (P<0.05). Nitrogen accumulation of the different bamboo species were ordered by D. oldhami > P. amarus > Ph. prominens, and the nitrogen storage was 370.28, 254.72 and 113.03 kg/ha, respectively. Nitrogen use efficiency was showed as Ph. prominens > P. amarus > D. oldhami, and the nitrogen element that was needed per ton of dry matter of the three bamboo species were 6.37, 6.53 and 7.96 kg, respectively.