Soil N₂O production and the ¦Ä¹⁵N-N₂O value: Their relationship with nitrifying/denitrifying bacteria and archaea during a growing season of soybean in northeast China

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• 作者：Zongwei Xia ; Hui Xu ; Guanxiong Chen ; Dan Dong ; E. Bai ; Liangguo Luo
• 关键词：Nitrous oxide (N2O) ; 15N isotope ; Ammonia-oxidizing bacteria (AOB) ; Ammonia-oxidizing archaea (AOA) ; Denitrification
• 刊名：European Journal of Soil Biology
• 出版年：2013
• 出版时间：September-October, 2013
• 年：2013
• 卷：58
• 期：Complete
• 页码：73-80
• 全文大小：503 K

文摘

Nitrous oxide, one of the principal greenhouse gases that can cause global warming, is mainly produced in soil via a series of microbial enzymatic processes. However, source identification of N₂O in soil has been a great challenge. In this study, a laboratory incubation experiment was conducted with soils sampled from a soybean field on six sampling dates to evaluate a new approach for identifying soil N₂O production processes. The isotopic signatures of soil-emitted N₂O, the copy numbers of nitrification- and denitrification-related genes, and some soil properties were monitored simultaneously. Results showed that the soil N₂O flux was related to water-filled pore space (WFPS) during the sampling period (r?=?0.73, p?<?0.01). The ¦Ä¹⁵N values of soil-emitted N₂O on the six sampling dates ranged from??11.3¡ë to?+1.6¡ë, and significant differences among these values were found. The ¦Ä¹⁵N-N₂O values were significantly correlated with the copy numbers of AOB amoA (r?=?0.80, p?<?0.01) but not with those of AOA amoA. These results suggested that soil WFPS was a determinative factor of N₂O production processes, and AOB played a more important role in N₂O production in the tested soil. Therefore, the combination of a stable isotopic signature with abundance of the soil microbial community should be a more effective approach to identify soil microbial processes of N₂O production.