Details

Autor(en) / Beteiligte

• Valente, Ralph J.
• Thornton, Frank C.
• Williams, Eric J.

Titel

Field comparison of static and flow-through chamber techniques for measurement of soil NO emission

Ist Teil von

• Journal of Geophysical Research, Washington, DC, 1995-10, Vol.100 (D10), p.21147-21152

Ort / Verlag

Washington, DC: Blackwell Publishing Ltd

Erscheinungsjahr

1995

Beschreibungen/Notizen

• A field comparison of flow‐through and static chamber techniques for measuring soil emissions of NO was performed on fertilized soil at a commercial cotton (Gossypium hirsutum L.) farm near Muscle Shoals, Alabama, during July 1992. The purpose of the study was to compare soil NOx. emissions data taken using two different techniques at a common field site. Emission rates with collocated chambers using the two techniques were compared, and spatial means were also compared for 17 National Oceanic and Atmospheric Administration (NOAA) plots and 10 Tennessee Valley Authority (TVA) plots. Emission rates of NO at the site covered a broad spectrum, ranging from less than 1 to greater than 100 ng N m−2 s−1. Data from collocated TVA static and NOAA flow‐through chambers showed a correlation coefficient of 0.98 with a linear regression slope of 0.97. A t test indicated that the mean difference was not statistically different than zero. The plot mean emission rates were 17.7 and 18.0 ng N m−2 s−1 for the TVA and NOAA chambers, respectively, for an 8‐day comparison period. These findings indicate that data sets collected with these methods are comparable and may be combined without concern for differences in technique. These results also reveal that the techniques used by each group in attempting to characterize overall site mean emissions are remarkably similar, despite differences in chamber size, plot location, extent of areal coverage, and random error associated with the measurements. This finding is significant in that it means that field data used to characterize emissions estimates by both protocols can be pooled to better estimate regional soil NO emission inventories.