@article{fdi:010074772,
  title = {{N}2{O} flux measurements over an irrigated maize crop : a comparison of three methods},
  author = {{T}allec, {T}. and {B}rut, {A}. and {J}oly, {L}. and {D}umelie, {N}. and {S}erca, {D}. and {M}ordelet, {P}. and {C}laverie, {N}. and {L}egain, {D}. and {B}arrie, {J}. and {D}ecarpenterie, {T}. and {C}ousin, {J}. and {Z}awilski, {B}. and {C}eschia, {E}. and {G}u{\'e}rin, {F}r{\'e}d{\'e}ric and {L}e {D}antec, {V}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}his paper presents the {N}itro{COSMES} campaign, aimed at testing and evaluating the performance of three methods for monitoring {N}2{O} fluxes over an agricultural field. {T}he experiment was conducted from {M}ay to {A}ugust 2012 at a site located in the south-west of {F}rance. {N}2{O} fluxes from a 24 ha irrigated maize field were measured using eddy covariance ({EC}), automated chamber ({AC}) and static chamber ({SC}) methodologies. {U}ncertainties were calculated according to the specificities of each set-up. {M}easurements were performed over a large range of water-filled pore spaces ({WFPS}), soil temperatures, and mineral nitrogen availability, and offered the opportunity to compare methodologies over a wide range of {N}2{O} emission intensities. {T}he average {N}2{O} fluxes were compared among the three methodologies during the same periods of measurement and for different intensities of emissions (low, moderate and high). {P}eriods of comparison were determined according to the {AC} results. {O}n average, the three methods gave comparable results for the low ({SC}: 14.7 +/- 2.2, {EC}: 15.7 +/- 10.1, {AC}: 17.5 +/- 1.6 ng {N}2{O}-{N} m(-2) s(-1)) and the high ({SC}: 131.7 +/- 22.1, {EC}: 125.3 +/- 8, {AC}: 125.1 +/- 8.9 ng {N}2{O}-{N} m(-2) s(-1)) {N}2{O} emission ranges. {F}or the moderate {N}2{O} emission range, {AC} measurements gave higher emissions (57.2 +/- 3.9 ng {N}2{O}-{N} m(-2) s(-1)) on average than both the {SC} (41.6 +/- 6.6 ng {N}2{O}-{N} m(-2) s(-1)) and {EC} (33.8 +/- 3.9 ng {N}2{O}-{N} m(-2) s(-1)) methods, which agreed better with each other. {T}he relative standard deviation coefficient ({RSD}) indicated that {EC} methodology gave highly variable values during periods of low {N}2{O} emissions, from -52.2 +/- 88.1 to 62.2 +/- 50.7 ng {N}2{O}-{N} m(-2) s(-1), with a mean {RSD} of 151%. {W}ater vapour effects (dilution and spectroscopic cross-sensitivity) were discussed in an attempt to explain the high variability in low {N}2{O} emission measurements. {E}ven after applying the {W}ebb term correction, there could still be a spectroscopic cross-sensitivity effect of water vapour on the {N}2{O} trace gas signal because of the layout of the analysers, which was not determined during the experiment. {T}his study underlined that {EC} methodology is a promising way to estimate and refine {N}2{O} budgets at the field scale and to analyse the effects of different agricultural practices more finely with continuous flux monitoring. {I}t also highlighted the need to continue the effort to assess and develop chambers and {EC} methodologies, especially for the low {N}2{O} emission measurement range, for which values and systematic uncertainties remain high and highly variable.},
  keywords = {{N}2{O} fluxes ; {E}ddy covariance ; {C}hambers ; {W}ater vapour effect ; {M}aize ; {FRANCE}},
  booktitle = {},
  journal = {{A}gricultural and {F}orest {M}eteorology},
  volume = {264},
  numero = {},
  pages = {56--72},
  ISSN = {0168-1923},
  year = {2019},
  DOI = {10.1016/j.agrformet.2018.09.017},
  URL = {https://www.documentation.ird.fr/hor/fdi:010074772},
}