Microbial Sulfate Reduction Rates in Soils in the Napa River Watershed, California, USA, 2021-2023

Agricultural sulfur (S) inputs are a major source of anthropogenic S to the environment, often stimulating microbial sulfate reduction (MSR) in downstream environments, which can drive a cascade of unintended ecosystem consequences. This dataset includes samples collected throughout the Napa River Watershed, California, USA, where routine, high S applications to vineyards are common. Sampling was focused confirming the presence of microbial sulfate reduction (MSR) within upland soils, challenging the conventional view that this process is restricted to fully saturated environments. We collected soil samples for sulfate concentrations, sulfate reduction rates (SRRs), and organic C content (Loss On Ignition, LOI) under three different hydrological conditions: while soils were moist (November 2021), dry (January/February 2022), and saturated (January/February 2023). We collected samples from a variety of different land cover types, including vineyard, vineyard stream, grassland, forest, forest stream, and wetland.