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The nitrogen budget of a hybrid poplar plantation in Minnesota |
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Canadian Journal of Forest Research,
Volume 20,
Issue 11,
1990,
Page 1818-1822
Karen L. Updegraff,
Donald R. Zak,
David F. Grigal,
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摘要:
The nitrogen (N) dynamics within short-rotation intensive-culture forest plantations are poorly understood. We developed a N budget for a 3-year-old hybrid poplar plantation under short-rotation intensive-culture management in northwestern Minnesota. Measured pools and fluxes of N included plant content, atmospheric input, litter fall, microbial biomass, mineralization, nitrification, and denitrification. Total aboveground tree biomass represented only 1.6% of the total N capital. Stable soil organic N was the largest pool, 5670 kg N•ha−1, and constituted 93% of all N within the site. Labile soil organic N and microbial N represented 5.6 and 1.6% of stable soil organic N, respectively. Nitrogen mineralization averaged 56 kg N•ha−1•year−1, and 66% of that production was oxidized to NO3−. Losses of N by denitrification and leaching were small compared with the magnitude of the other fluxes. Results suggest that a relatively high rate of plant uptake and production maintained NH4+and NO3−pools at low levels, minimizing N exports to the atmosphere and groundwater.
ISSN:0045-5067
DOI:10.1139/x90-244
出版商:NRC Research Press
年代:1990
数据来源: NRC
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