Atmospheric So2 Emissions Since the Late 1800s Change Organic Sulfur Forms in Humic Substance Extracts of Soils

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es702315g· OSTI ID:959791

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

Atmospheric SO2 emissions in the UK and globally increased 6- and 20-fold, respectively, from the mid-1800s to the 1960s resulting in increased S deposition, acid rain, and concurrent acidification of terrestrial and aquatic ecosystems. Structural analyses using synchrotron-based X-ray near-edge spectroscopy (XANES) on humic substance extracts of archived samples from the Rothamsted Park Grass Experiment reveal a significant (R2 = -0.58; P < 0.05; N = 7) shift in soil organic sulfur (S) forms, from reduced to more oxidized organic S between 1876 and 1981, even though soil total S contents remained relatively constant. Over the last 30 years, a decrease in emissions and consequent S deposition has again corresponded with a change of organic S structures of humic extractsreverting in the direction of their early industrial composition. However, the observed reversal lagged behind reductions in emissions by 19 years, which was computed using cross correlations between time series data (R2 = 0.66; P = 0.0024; N = 11). Presently, the ratio of oxidized-to-reduced organic S in humic substance extracts is nearly double that of early industrial times at identical SO2 emission loads. The significant and persistent structural changes of organic S in humic substances as a response to SO2 emissions and S deposition may have effects on recuperation of soils and surface waters from acidification.

• Research Organization: Brookhaven National Laboratory
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 959791
• Report Number(s): BNL--82777-2009-JA
• Journal Information: Environmental Science and Technology, Journal Name: Environmental Science and Technology Vol. 42; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ACID RAIN
ACIDIFICATION
AQUATIC ECOSYSTEMS
DEPOSITION
GRAMINEAE
SOILS
SPECTROSCOPY
SULFUR
SURFACE WATERS