Global Research Alliance N2O chamber methodology guidelines: Recommendations for 2 deployment and accounting for sources of variability

A - Papers appearing in refereed journals

Charteris, A., Chadwick, D. R., Thorman, R. E., Vallejo, A., De Klein, C. A. M., Rochette, P. and Cardenas, L. M. 2020. Global Research Alliance N2O chamber methodology guidelines: Recommendations for 2 deployment and accounting for sources of variability. Journal of Environmental Quality. https://doi.org/10.1002/jeq2.20126

AuthorsCharteris, A., Chadwick, D. R., Thorman, R. E., Vallejo, A., De Klein, C. A. M., Rochette, P. and Cardenas, L. M.
Abstract

Adequately estimating soil nitrous oxide (N2O) emissions using static chambers is challenging due to the high spatial variability and episodic nature of these fluxes. This paper discusses how static chamber N2O experiments can be designed, and protocols implemented, to better account for this variability and reduce the uncertainty of N2O emission estimates. It is part of a series of papers in this special issue, each discussing a particular aspect of N2O chamber methodology. Aspects of experimental design and sampling affected by spatial variability include site selection, and chamber layout, size and areal coverage. Where used, treatment application adds a further level of spatial variability. Time of day, frequency and duration of sampling (both in terms of individual chamber closures and overall experiment duration) affect the temporal variability captured. In addition, we present best practice recommendations for experimental chamber installation and sampling protocols to minimise the introduction of further uncertainty. To obtain the best N2O emission estimates, resources should be allocated to minimise the overall uncertainty in line with experiment objectives. In some cases, this will mean prioritising individual flux measurements and increasing their accuracy and precision by, for example, collecting ≥4 headspace samples during each chamber closure. However, where N2O fluxes are exceptionally spatially variable, for example, in heterogeneous agricultural landscapes, such as uneven and woody grazed pastures, using available resources to deploy more chambers with fewer headspace samples per chamber may be beneficial. Similarly, for particularly episodic N2O fluxes, generated for example by irrigation or freeze-thaw cycles, increasing chamber sampling frequency will improve the accuracy and reduce the uncertainty of temporally interpolated N2O fluxes

Year of Publication2020
JournalJournal of Environmental Quality
Digital Object Identifier (DOI)https://doi.org/10.1002/jeq2.20126
Open accessPublished as non-open access
FunderDepartment of Environment, Food and Rural Affairs
Output statusIn press
Publication process dates
Accepted16 Jul 2020
PublisherAmerican Society of Agronomy (ASA)
ISSN0047-2425

Permalink - https://repository.rothamsted.ac.uk/item/98164/global-research-alliance-n2o-chamber-methodology-guidelines-recommendations-for-2-deployment-and-accounting-for-sources-of-variability

Restricted files

Accepted author manuscript

Under embargo indefinitely

Supplemental file

Under embargo indefinitely

26 total views
2 total downloads
14 views this month
0 downloads this month