TY - JOUR
T1 - Modeling soil moisture and oxygen effects on soil biogeochemical cycles including dissimilatory nitrate reduction to ammonium (DNRA)
AU - Rubol, Simonetta
AU - Manzoni, Stefano
AU - Bellin, Alberto
AU - Porporato, Amilcare
N1 - Funding Information:
We acknowledge the support of the ProvinciaAutonoma di Trento and the European Commission within the 7° ProgrammaQuadro – Azioni Marie Curie Cofund, PAT-Outgoing. Partial support for this work was provided by the US Department of Energy (DOE) through the Office of Biological and Environmental Research (BER) Terrestrial Carbon Processes (TCP) program (DE-SC0006967), the US Department of Agriculture (2011-67003-30222),the US National Science Foundation (CBET-1033467; DEB-1145875/1145649), and the Faculty of Natural Resources and Agricultural Sciences, Swedish University of Agricultural Sciences. Finally, we thank the editor and the anonymous reviewers for useful comments that helped improve the paper.
PY - 2013/10
Y1 - 2013/10
N2 - The emission of greenhouse gasses (GHG) from soils is controlled by biogeochemical reactions and the physical constraints on gas diffusion to the soil surface. Here we present and discuss a mathematical model that couples oxygen and soil water dynamics to biochemical reactions and gas transport to explore the major drivers of trace gas emission at daily time scale in unsaturated soils. The model accounts for trace gas emissions (CO2, and N2O from nitrification and denitrification), as well as for the competition for nitrate by denitrification and dissimilatory reduction of nitrate to ammonium (DNRA). Our results indicate that explicit modeling of oxygen dynamics is important when re-aeration is limited, such as under wet conditions, in particular for fine-textured soils. The balance of labile substrate, oxygen, and water availabilities explain the observed peaks in GHG emissions at moisture values around the soil field capacity. The timing of these peaks during a dry-down is delayed in fine-textured soils, due to the slower drying and limited gas exchange rates. In addition, N2O emissions may be limited by DNRA at high soil moisture.
AB - The emission of greenhouse gasses (GHG) from soils is controlled by biogeochemical reactions and the physical constraints on gas diffusion to the soil surface. Here we present and discuss a mathematical model that couples oxygen and soil water dynamics to biochemical reactions and gas transport to explore the major drivers of trace gas emission at daily time scale in unsaturated soils. The model accounts for trace gas emissions (CO2, and N2O from nitrification and denitrification), as well as for the competition for nitrate by denitrification and dissimilatory reduction of nitrate to ammonium (DNRA). Our results indicate that explicit modeling of oxygen dynamics is important when re-aeration is limited, such as under wet conditions, in particular for fine-textured soils. The balance of labile substrate, oxygen, and water availabilities explain the observed peaks in GHG emissions at moisture values around the soil field capacity. The timing of these peaks during a dry-down is delayed in fine-textured soils, due to the slower drying and limited gas exchange rates. In addition, N2O emissions may be limited by DNRA at high soil moisture.
KW - N cycle
KW - Nitrate ammonification
KW - Nitrous oxyde emissions
KW - Oxygen dynamics
KW - Soil texture
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U2 - 10.1016/j.advwatres.2013.09.016
DO - 10.1016/j.advwatres.2013.09.016
M3 - Article
AN - SCOPUS:84887007444
SN - 0309-1708
VL - 62
SP - 106
EP - 124
JO - Advances in Water Resources
JF - Advances in Water Resources
ER -