Open AccessAn experimental determination of the scale length of N 2 O in the soil of a grassland
Author(s) -
Neftel Albrecht,
Blatter Andreas,
Schmid Martin,
Lehmann Bernhard,
Tarakanov Sergei V.
Publication year - 2000
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2000jd900088
Subject(s) - flux (metallurgy) , deposition (geology) , grassland , atmosphere (unit) , soil science , diffusion , analytical chemistry (journal) , relaxation (psychology) , atmospheric sciences , environmental science , chemistry , hydrology (agriculture) , physics , environmental chemistry , geology , meteorology , thermodynamics , geomorphology , agronomy , geotechnical engineering , organic chemistry , sediment , biology , psychology , social psychology
Concentration profiles of N 2 O in a grassland soil and dynamic response curves to disturbance of the soil concentration (relaxation curves) were measured with a new membrane tube technique. Diffusive properties of the soil were derived from 222 Rn measurements. The mathematical analysis of the relaxation curves yielded N 2 O uptake rates U soil diffusivities D s , scale lengths z * , and production rates P at different levels under the surface. The following ranges were found during 2 days of measurements: D s = (0.4–5) × 10 −7 m 2 s −1 , U = (1–20) × 10 −4 s −1 , z * = 0.7–2.8 cm, and P = 0.02–4.4 ppb s −1 . These values were used to reproduce the measured N 2 O concentration profiles with a one‐dimensional diffusive transport model of N 2 O in the soil air‐filled pore space and to deduce flux profiles. Bidirectional fluxes occurred with small deposition fluxes up to a few ppt ms −1 during intensive growing phases of the grass. Uptake rates were high enough that N 2 O produced at greater depth did not reach the atmosphere.