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This article in SSSAJ

  1. Vol. 59 No. 5, p. 1308-1310
    Received: Oct 13, 1994

    * Corresponding author(s): glhutch@lamar.colostate.edu
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Chamber Measurement of Soil-Atmosphere Gas Exchange: Linear vs. Diffusion-Based Flux Models

  1. W. H. Anthony,
  2. G. L. Hutchinson  and
  3. G. P. Livingston
  1. Cooperative Agricultural Research Center, Prairie View AM Univ., P.O. Drawer U, Prairie View, TX 77446
    USDA-ARS, Soil-Plant Nutrient Research Unit, P.O. Box E, Fort Collins, CO 80522
    Earth Systems Science Division, NASA Ames Research Center, SGE: 239-20, Moffett Field, CA 94035



We compared linear regression with a diffusion-based model for N2O flux estimation using non-steady-state chamber gas concentrations from a long-term study of N cycling in a managed grass pasture on sandy soil in southern Texas. Of 2224 chamber deployments, 449 met criteria established for using the diffusion-based model, which yielded flux estimates that averaged 54% larger than linear regression (n = 3). Although they represented only about 20% of all chamber deployments, this group included most of the data with greatest influence on the magnitude and dynamics of total N2O exchange at our site; e.g., of the 263 fluxes >10 g N ha−1 d−1, 192 (or 73%) were included. Apparently, application of a linear model to nonlinear chamber concentration data represents a potentially serious source of measurement bias that may influence not only summary statistics for the experiment, but also larger scale budgets based partially or wholly on those data.

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