RT journal article
T1 Nitrous oxide variability along an estuary influenced by agricultural land use (Guadalquivir estuary, SW Spain)
A1 Sánchez Rodríguez, Jairo
A1 Sierra Padilla, Ana
A1 Moreno Ortiz, Samuel
A1 Forja Pajares, Jesús
A1 Ortega Díaz, Teodora
A2 Química Física
K1 Nitrous oxide
K1 Water-atmosphere fluxes
K1 Benthic fluxes
K1 Reactivity
K1 Guadalquivir estuary
AB The Guadalquivir Estuary is the largest estuary in the southwest basin of the Iberian Peninsula, which is subject to strong anthropogenic influence such as the damming or the multitude of crop fields on its margins. Nitrous Oxide (N2O) variability is analysed considering the influence of temperature, salinity, water-atmosphere fluxes, benthic fluxes, reactivity and lateral inputs. N2O increases along the salinity gradient, with values ranging from 5.9 to 103.3 nmol L-1. Thus, values of N2O concentration are very close to equilibrium with the atmosphere at the mouth, while in the inner zone the fluxes to the atmosphere are higher, showing the greatest variability of N2O in the estuary (74.26 ± 7.41 µmol m-2 d-1). Sediments act as a source of N2O to the water column, with benthic fluxes presenting a wide range from 2 to 20 µmol m-2 d-1. Denitrification processes in the sediments may be important in the inner part of the estuary, where negative benthic fluxes of nitrate have been observed. Production rates of N2O in the water column are estimated from incubation experiments, resulting in higher production with temperature, and lower with salinity. Lateral inputs are calculated by balance of the different processes characterized and seems to be an important factor influencing N2O variability in the inner zone of the estuary.
PB Elsevier
SN 0304-4203
YR 2024
FD 2024
LK http://hdl.handle.net/10498/34010
UL http://hdl.handle.net/10498/34010
LA eng
NO This work was supported by the Spanish CICYT (Spanish Program for Science and Technology)
DS Repositorio Institucional de la Universidad de Cádiz
RD 10-nov-2026