Lowering N2O emissions from soils using eucalypt biochar: the importance of redox reactions

Quin P., Joseph Stephen, Husson Olivier, Donne Scott, Mitchell David R.G., Munroe Paul, Phelan D., Cowie Annette, van Zwieten Lukas. 2015. Lowering N2O emissions from soils using eucalypt biochar: the importance of redox reactions. Scientific Reports, 5 (16773), 14 p.

https://doi.org/10.1038/srep16773

Article de revue ; Article de recherche ; Article de revue à facteur d'impact Revue en libre accès total

Version publiée - Anglais
Sous licence

.
Quin Joseph Husson et al - 2015 -Lowering N2O emissions_redox reactions.pdf
Télécharger (1MB)

Quartile : Outlier, Sujet : MULTIDISCIPLINARY SCIENCES

Résumé : Agricultural soils are the primary anthropogenic source of atmospheric nitrous oxide (N2O), contributing to global warming and depletion of stratospheric ozone. Biochar addition has shown potential to lower soil N2O emission, with the mechanisms remaining unclear. We incubated eucalypt biochar (550 °C) – 0, 1 and 5% (w/w) in Ferralsol at 3 water regimes (12, 39 and 54% WFPS) – in a soil column, following gamma irradiation. After N2O was injected at the base of the soil column, in the 0% biochar control 100% of expected injected N2O was released into headspace, declining to 67% in the 5% amendment. In a 100% biochar column at 6% WFPS, only 16% of the expected N2O was observed. X-ray photoelectron spectroscopy identified changes in surface functional groups suggesting interactions between N2O and the biochar surfaces. We have shown increases in -O-C = N /pyridine pyrrole/NH3, suggesting reactions between N2O and the carbon (C) matrix upon exposure to N2O. With increasing rates of biochar application, higher pH adjusted redox potentials were observed at the lower water contents. Evidence suggests that biochar has taken part in redox reactions reducing N2O to dinitrogen (N2), in addition to adsorption of N2O.

Mots-clés Agrovoc : réduction des émissions, charbon de bois, Eucalyptus, fertilisation, sol agricole, oxyde d'azote, gaz à effet de serre, réchauffement global, biochimie, spectroscopie aux rayons x, Microscopie électronique, propriété physicochimique du sol