Abiotic nitrous oxide production from hydroxylamine in soils and their dependence on soil properties. (May 2015)

• Record Type: Journal Article
• Authors: Heil, Jannis; Liu, Shurong; Vereecken, Harry; Brüggemann, Nicolas
• Is Part Of: Soil biology and biochemistry. Volume 84(2015)
• Page Start: 107
• Page End: 115
• Publication Date: 2015-05
• Subjects: Coupled biotic–abiotic process -- Nitrification -- Intermediate -- N2O -- NH2OH; Soil biochemistry -- Periodicals; Soil biology -- Periodicals; Sols -- Biochimie -- Périodiques; Sols -- Biologie -- Périodiques; Sols -- Microbiologie -- Périodiques; Bodembiologie; Biochemie; 631.46
• DOI: 10.1016/j.soilbio.2015.02.022
• Languages: English
• ISSNs: 0038-0717

Abstract

Abstract: Despite the fact that microbial nitrification and denitrification are considered the major soil N2 O emission sources, especially from agricultural soils, several abiotic reactions involving the nitrification intermediate hydroxylamine (NH2 OH) have been identified leading to N2 O emissions, but are being neglected in most current studies. Here, we studied N2 O formation from NH2 OH in cropland, grassland, and forest soils in laboratory incubation experiments. Incubations were conducted with and without the addition of NH2 OH to non-sterile and sterile soil samples. N2 O evolution was quantified with gas chromatography and further analyzed with online laser absorption spectroscopy. Additionally, the isotopic signature of the produced N2 O (δ 15 N, δ 18 O, and 15 N site preference) was analyzed with isotope ratio mass spectrometry. While the forest soil samples showed hardly any N2 O evolution upon the addition of NH2 OH, immediate and very large formation of N2 O was observed in the cropland soil, also in sterilized samples. Correlation analysis revealed soil parameters that might explain the variability of NH2 OH-induced N2 O production to be: soil pH, C/N ratio, and Mn content. Our results suggest a coupled biotic–abiotic production of N2 O during nitrification, e.g. due to leakage of the nitrification intermediate NH2 OH with subsequent reaction with the soil matrix. Highlights: We propose a coupled biotic–abiotic N2 O production during nitrification. Hydroxylamine seems to be the key intermediate in abiotic N2 O formation in soils. We found high hydroxylamine-induced N2 O emissions from a sterile agricultural soil. One or more of soil pH, C/N ratio, and Mn content seem to control abiotic N2 O formation.