Soil degassing during watering: An overlooked soil N2O emission process

Junzeng Xu; Qi Wei; Shihong Yang; Linxian Liao; Zhiming Qi; Weiguang Wang

doi:10.1016/j.envpol.2018.06.103

Soil degassing during watering: An overlooked soil N₂O emission process

Environ Pollut. 2018 Nov;242(Pt A):257-263. doi: 10.1016/j.envpol.2018.06.103. Epub 2018 Jun 30.

Authors

Junzeng Xu¹, Qi Wei², Shihong Yang¹, Linxian Liao³, Zhiming Qi⁴, Weiguang Wang⁵

Affiliations

¹ State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098, China; College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, 210098, China.
² State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098, China; College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, 210098, China. Electronic address: weiqi8855116@163.com.
³ College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, 210098, China.
⁴ Department of Bioresource Engineering, McGill University, Quebec, H9X 3V9, Canada.
⁵ State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098, China.

PMID: 29990933
DOI: 10.1016/j.envpol.2018.06.103

Abstract

Pulse diffusive nitrous oxide (N₂O) emission following water application is well documented, whereas N₂O emission caused by soil water-air displacement during the watering process (termed as soil degassing) has been largely overlooked. Watering-induced N₂O emissions from ten different soils in China were quantified, and found to range from 74.4 ± 6.7 to 678.1 ± 36.6 μg N₂O m^-2 h^-1 in surface watered (SW) soils, and from 45.6 ± 4.4 to 358.1 ± 23.6 μg N₂O m^-2 h^-1 in subsurface watered (SUW) soils. These N₂O fluxes were much larger than the diffusive N₂O flux from the same soil either under dry (7.9%-9.6% water filled pore space, WFPS) or wet (85.1%-93.6% WFPS) conditions. The watering process (the water infiltration process upon irrigation/rainfall or the process of shallow groundwater uplifting) resulted in massive N₂O emissions.

Keywords: Nitrous oxide; Rainfall; Shallow groundwater lifting; Soil degassing; Watering.

MeSH terms

Agricultural Irrigation
Air Pollutants / analysis*
China
Models, Chemical*
Nitrous Oxide / analysis*
Rain
Soil / chemistry*
Water

Substances

Air Pollutants
Soil
Water
Nitrous Oxide