DOI: 10.1111/gcb.12461
论文题名: Excessive use of nitrogen in Chinese agriculture results in high N2O/(N2O+N2) product ratio of denitrification, primarily due to acidification of the soils
作者: Qu Z. ; Wang J. ; Almøy T. ; Bakken L.R.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2014
卷: 20, 期: 5 起始页码: 1685
结束页码: 1698
语种: 英语
英文关键词: Agriculture
; Denitrification
; Fertilizer
; Nitrous oxide
; Soil acidification
Scopus关键词: acidification
; agricultural soil
; concentration (composition)
; denitrification
; fertilizer
; leaching
; nitrate
; nitrogen
; nitrous oxide
; soil emission
; soil respiration
; China
; fertilizer
; nitric acid derivative
; nitrogen
; nitrous oxide
; soil
; agriculture
; chemistry
; China
; denitrification
; metabolism
; pH
; soil
; Agriculture
; China
; Denitrification
; Fertilizers
; Hydrogen-Ion Concentration
; Nitrates
; Nitrogen
; Nitrous Oxide
; Soil
英文摘要: China is the world's largest producer and consumer of fertilizer N, and decades of overuse has caused nitrate leaching and possibly soil acidification. We hypothesized that this would enhance the soils' propensity to emit N2O from denitrification by reducing the expression of the enzyme N2O reductase. We investigated this by standardized oxic/anoxic incubations of soils from five long-term fertilization experiments in different regions of China. After adjusting the nitrate concentration to 2 mM, we measured oxic respiration (R), potential denitrification (D), substrate-induced denitrification, and the denitrification product stoichiometry (NO, N2O, N2). Soils with a history of high fertilizer N levels had high N2O/(N2O+N2) ratios, but only in those field experiments where soil pH had been lowered by N fertilization. By comparing all soils, we found a strong negative correlation between pH and the N2O/(N2O+N2) product ratio (r2 = 0.759, P < 0.001). In contrast, the potential denitrification (D) was found to be a linear function of oxic respiration (R), and the ratio D/R was largely unaffected by soil pH. The immediate effect of liming acidified soils was lowered N2O/(N2O+N2) ratios. The results provide evidence that soil pH has a marginal direct effect on potential denitrification, but that it is the master variable controlling the percentage of denitrified N emitted as N2O. It has been known for long that low pH may result in high N2O/(N2O+N2) product ratios of denitrification, but our documentation of a pervasive pH-control of this ratio across soil types and management practices is new. The results are in good agreement with new understanding of how pH may interfere with the expression of N2O reductase. We argue that the management of soil pH should be high on the agenda for mitigating N2O emissions in the future, particularly for countries where ongoing intensification of plant production is likely to acidify the soils. © 2013 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/62208
Appears in Collections: 影响、适应和脆弱性
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作者单位: Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, PO box 5003, Aas, N-1432, Norway; College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China; Department of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences, PO box 5003, Aas, N-1432, Norway
Recommended Citation:
Qu Z.,Wang J.,Almøy T.,et al. Excessive use of nitrogen in Chinese agriculture results in high N2O/(N2O+N2) product ratio of denitrification, primarily due to acidification of the soils[J]. Global Change Biology,2014-01-01,20(5)