Sulfur isotopes reveal agricultural changes to the modern sulfur cycle

Details

• Journal Title:
  Environmental Research Letters
• Personal Author:
  Hermes, Anna L ; Dawson, Todd E ; Hinckley, Eve-Lyn S
• NOAA Program & Office:
  NESDIS (National Environmental Satellite, Data, and Information Service) ; NCEI (National Centers for Environmental Information)
• Description:
  The environmental fates and consequences of intensive sulfur (S) applications to croplands are largely unknown. In this study, we used S stable isotopes to identify and trace agricultural S from field-to-watershed scales, an initial and timely step toward constraining the modern S cycle. We conducted our research within the Napa River Watershed, California, US, where vineyards receive frequent fungicidal S sprays. We measured soil and surface water sulfate concentrations ([SO4 2−]) and stable isotopes (δ 34S–SO4 2−), which we refer to in combination as the ‘S fingerprint’. We compared samples collected from vineyards and surrounding forests/grasslands, which receive background atmospheric and geologic S sources. Vineyard δ 34S–SO4 2− values were 9.9 ± 5.9‰ (median ± interquartile range), enriched by ∼10‰ relative to forests/grasslands (−0.28 ± 5.7‰). Vineyards also had roughly three-fold higher [SO4 2−] than forests/grasslands (13.6 and 5.0 mg SO4 2−–S l−1, respectively). Napa River δ 34S–SO4 2− values, reflecting the watershed scale, were similar to those from vineyards (10.5 ± 7.0‰), despite vineyard agriculture constituting only ∼11% of the watershed area. Combined, our results provide important evidence that agricultural S is traceable at field-to-watershed scales, a critical step toward determining the consequences of agricultural alterations to the modern S cycle.
• Keywords:
  General Environmental Science Public Health, Environmental And Occupational Health Renewable Energy, Sustainability And The Environment Public Health, Environmental And Occupational Health Renewable Energy, Sustainability And The Environment Public Health, Environmental And Occupational Health Renewable Energy, Sustainability And The Environment
• Source:
  Environmental Research Letters, 17(5), 054032
• DOI:
  https://doi.org/10.1088/1748-9326/ac6683
• ISSN:
  1748-9326
• Format:
  PDF
• Publisher:
  IOP Publishing
• Document Type:
  Journal Article
• License:
  https://creativecommons.org/licenses/by/4.0
• Rights Information:
  CC BY
• Compliance:
  Submitted
• Main Document Checksum:
  urn:sha256:25d7f278a76d0182a120c44b9c22210bdcb370b731bb5c3f84dcee1003161ca9
• Download URL:
  https://repository.library.noaa.gov/view/noaa/51922/noaa_51922_DS1.pdf
• File Type:
  [PDF - 4.43 MB ]