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Journal of Environmental Quality Abstract - Atmospheric Pollutants and Trace Gases

Tillage and Field Scale Controls on Greenhouse Gas Emissions

 

This article in JEQ

  1. Vol. 35 No. 3, p. 714-725
     
    Received: Sept 8, 2005


    * Corresponding author(s): ecolee@ucdavis.edu
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doi:10.2134/jeq2005.0337
  1. Juhwan Lee *a,
  2. Johan Sixa,
  3. Amy P. Kingb,
  4. Chris van Kessela and
  5. Dennis E. Rolstonb
  1. a Department of Plant Sciences, University of California, Davis, CA 95616
    b Department of Land, Air, and Water Resources, University of California, Davis, CA 95616

Abstract

There is a lack of understanding of how associations among soil properties and management-induced changes control the variability of greenhouse gas (GHG) emissions from soil. We performed a laboratory investigation to quantify relationships between GHG emissions and soil indicators in an irrigated agricultural field under standard tillage (ST) and a field recently converted (2 yr) to no-tillage (NT). Soil cores (15-cm depth) were incubated at 25°C at field moisture content and 75% water holding capacity. Principal component analysis (PCA) identified that most of the variation of the measured soil properties was related to differences in soil C and N and soil water conditions under ST, but soil texture and bulk density under NT. This trend became more apparent after irrigation. However, principal component regression (PCR) suggested that soil physical properties or total C and N were less important in controlling GHG emissions across tillage systems. The CO2 flux was more strongly determined by microbial biomass under ST and inorganic N content under NT than soil physical properties. Similarly, N2O and CH4 fluxes were predominantly controlled by NO3 content and labile C and N availability in both ST and NT soils at field moisture content, and NH4 + content after irrigation. Our study indicates that the field-scale variability of GHG emissions is controlled primarily by biochemical parameters rather than physical parameters. Differences in the availability and type of C and N sources for microbial activity as affected by tillage and irrigation develop different levels and combinations of field-scale controls on GHG emissions.

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Copyright © 2006. American Society of Agronomy, Crop Science Society of America, Soil Science SocietyASA, CSSA, SSSA