Ma Q.,CAS Shenyang Institute of Applied Ecology |
Yu W.-T.,CAS Shenyang Institute of Applied Ecology |
Zhou H.,CAS Shenyang Institute of Applied Ecology |
Xu Y.G.,CAS Shenyang Institute of Applied Ecology |
And 4 more authors.
Chinese Journal of Applied Ecology | Year: 2010
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.