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Titel |
Organically fertilized tea plantation stimulates N2O emissions and lowers NO fluxes in subtropical China |
VerfasserIn |
Z. Yao, Y. Wei, C. Liu, X. Zheng, B. Xie |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 12, no. 20 ; Nr. 12, no. 20 (2015-10-16), S.5915-5928 |
Datensatznummer |
250118128
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Publikation (Nr.) |
copernicus.org/bg-12-5915-2015.pdf |
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Zusammenfassung |
Tea plantations are rapidly expanding in China and other countries in the
tropical and subtropical zones, but so far there are very few studies
including direct measurements of nitrogenous gas fluxes from tea
plantations. On the basis of 2-year field measurements from 2012 to 2014, we
provided an insight into the assessment of annual nitrous oxide (N2O)
and nitric oxide (NO) fluxes from Chinese subtropical tea plantations under
three practices of conventional urea application, alternative oilcake
incorporation and no nitrogen fertilization. Clearly, the N2O and NO
fluxes exhibited large intra- and inter-annual variations, and furthermore,
their temporal variability could be well described by a combination of soil
environmental factors including soil mineral N, water-filled pore space and
temperature, based on a revised "hole-in-the-pipe" model. Averaged over a
2-year study, annual background N2O and NO emissions were approximately
4.0 and 1.6 kg N ha−1 yr−1, respectively. Compared to no nitrogen
fertilization, both urea and oilcake application significantly stimulated
annual N2O and NO emissions, amounting to 14.4–32.7 kg N2O–N ha−1 yr−1
and at least 12.3–19.4 kg NO–N ha−1 yr−1,
respectively. In comparison with conventional urea treatment, on average,
the application of organic fertilizer significantly increased N2O
emission by 71 % but decreased NO emission by 22 %. Although the
magnitude of N2O and NO fluxes was substantially influenced by the
source of N, the annual direct emission factors of N fertilizer were estimated to
be 2.8–5.9, 2.7–4.0 and 6.8–9.1 % for N2O, NO and
N2O+NO, respectively, which are significantly higher than those
defaults for global upland croplands. This indicated that the rarely
determined N2O and NO formation appeared to be a significant pathway in
the nitrogen cycle of tea plantations, which are a potential source of
national nitrogenous gases inventory. |
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