Sulphur Speciation and Turnover in Soils: Evidence from Sulfur K-Edge XANES Spectroscopy and Isotope Dilution Studies

Journal Article · Sun Jan 01 04:00:00 EST 2006 · Soil Biol. Biochem.

DOI:https://doi.org/10.1016/j.soilbio.2005.08.013· OSTI ID:914215

Zhao, F; Lehmann, J; Solomon, D; Fox, M; McGrath, S

Sulphur K-edge X-ray absorption near edge structure (XANES) spectroscopy was used to quantify S species in humic substance extracts from ten soils from the UK, China and New Zealand, which differ in land use and agricultural management. XANES spectroscopy showed the presence of most reduced (sulphides, disulphides, thiols and thiophenes), intermediate (sulphoxides and sulphonates) and highly oxidised S (ester sulphates) forms, with the three groups representing 14-32%, 33-50% and 22-53% of the organic S in the humic substance extracts, respectively. Land use had a profound influence on the relative proportions of S species. Well-drained arable soils generally had a higher proportion of organic S present in the most oxidised form than the grassland soils collected nearby, whereas paddy soils showed a more reduced profile due to episodic flooding. In the Broadbalk Classical Experiment at Rothamsted, reversion of an arable system to grassland or woodland in the 1880s resulted in an increase of the most reduced and intermediate S species at the expense of the most oxidised S species. Long-term applications of farmyard manure to an arable plot also shifted S species from the most oxidised to the intermediate and the most reduced species. Sulphur immobilisation and gross mineralisation were determined in seven soils using the {sup 35}S isotope dilution method. Gross mineralisation during a 53-day incubation correlated more closely with the amounts of the most reduced and intermediate S species than with the most oxidised S species, suggesting that the former (C-bonded S) were the main source of organic S for mineralisation in the short-term.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 914215
• Report Number(s): BNL--78783-2007-JA
• Journal Information: Soil Biol. Biochem., Journal Name: Soil Biol. Biochem. Journal Issue: 5 Vol. 38; ISSN SBIOAH; ISSN 0038-0717
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
ABSORPTION
INCUBATION
ISOTOPE DILUTION
LAND USE
MANAGEMENT
MANURES
POLYCYCLIC SULFUR HETEROCYCLES
SOILS
SPECTROSCOPY
SULFUR
THIOLS
national synchrotron light source