[Nutrient concentration and storage in different organs of Eucalyptus under effects of nitrogen topdressing].
A field experiment was conducted to study the effects of nitrogen (N) topdressing on the biomass accumulation and nutrient concentration and storage in different organs of two-year-old eucalyptus. Comparing with the control, N topdressing increased the eucalyptus biomass by 24.2%. Branch had the highest increment (38.2%), while leaf had the lowest one. The nutrient uptake under N topdressing was improved significantly, with the order of P > K > N > Mg > Ca > Si. Leaf had the highest contents of N, P, Mg, and Si; trunk had the highest storage of K; while branch had the most significant increase of nutrient concentration and storage. The N, P, and K were recycled mainly through internal flux, with 73.8% of N, 79.1% of P, and 72.9% of K in leaf transferred back to the plant before leaf fallen, and the external flux of these three nutrients only occupied 14.8%, 7.7%, and 8.6% of their total storage in the tree, respectively. The Ca, Mg and Si were the external flux elements, especially for Ca. 89.2% of Ca in leaf was cycled in external flux, accounting for 25.9% of its total storage in the tree.
Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China. qma@iae.ac.cn
Qiang
Q
Ma
Wan-Tai
WT
Yu
Hua
H
Zhou
Yong-Gang
YG
Xu
Jin-Ning
JN
Chen
Gui-Jin
GJ
Chen
Shu-Ying
SY
Liu
Li
L
Deng
D018533:Biomass; D005052:Eucalyptus / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D005308:Fertilizers; D009584:Nitrogen / Q000378:metabolism / Q000494:pharmacology*; D010710:Phosphates / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism / Q000502:physiology; D018547:Plant Stems / Q000378:metabolism* / Q000502:physiology
D005308:Fertilizers; D010710:Phosphates; D009584:Nitrogen