Selection of the most suitable sampling time for static chambers for the estimation of daily mean N₂O flux from soils

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• 作者：Bruno J.R. Alves^a ; ^{bruno@cnpab.embrapa.br} ; Keith A. Smith^b ; ^{keith.smith@ed.ac.uk} ; Rilner A. Flores^c ; ^{rilner1@hotmail.com} ; Abmael S. Cardoso^c ; ^{abmael2@gmail.com} ; William R.D. Oliveira^c ; ^{ruralwillian@hotmail.com} ; Claudia P. Jantalia^a ; ^{claudia@cnpab.embrapa.br} ; Segundo Urquiaga^a ; ^{urquiaga@cnpab.embrapa.br} ; Robert M. Boddey^a ; ^{bob@cnpab.embrapa.br}
• 关键词：Air temperature ; Diurnal variation ; Nitrous oxide ; Soil moisture ; Static chamber
• 刊名：Soil Biology & Biochemistry
• 出版年：2012
• 出版时间：March 2012
• 年：2012
• 卷：46
• 期：Complete
• 页码：129-135
• 全文大小：595 K

文摘

Soil N₂O fluxes are frequently assessed by the use of static chambers with a single daily sampling. In this study, two experiments were conducted in two contrasting climatic locations, one in Edinburgh, UK, and the other at Serop¨¦dica, Rio de Janeiro State, Brazil. Soil N₂O fluxes were monitored every 6?h for 30 days during the summer in Edinburgh by the use of an automatic chamber system, and every 3?h for 5 days at Serop¨¦dica, using a manually-sampled static chamber. Air and soil temperatures were also measured at the same time as the N₂O fluxes. The principal driver of N₂O flux within any diurnal period was found to be soil temperature. Regression analysis showed that, for both places, the evenings (21:00-22:00?h) and mornings (09:00-10:00?h), were the times that the flux best represented the daily mean. The ability to work in daylight make the morning period the preferred one.