Soil degassing during watering: An overlooked soil N2O emission process

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

Soil degassing during watering: An overlooked soil N2O emission process

2018

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.

Показать больше [+]