Using species sensitivity distributions to assess the toxicity of pesticides on nitrifiers and broader microbial groups: From single-species tests to soil amplicon sequencing.

Soil microbial groups show differing sensitivities to metsulfuron-methyl, with hazard concentration 5% (HC 5 ) values of 0.001 mg kg -1 for AOM and 0.042 mg kg -1 for prokaryotes, indicating variable risk levels.

• Why it matters: Understanding pesticide effects on soil microbes is crucial for ecosystem health, but conventional tests often fail to capture the full community response, especially for microbial diversity.
• What they did: Researchers combined amplicon sequencing with species sensitivity distributions (SSDs) to assess metsulfuron-methyl's impact on AOM, prokaryotes, and fungi, deriving hazard thresholds from both single-species and soil community data.
• The result: Findings suggest a potential risk to AOM based on single-species data, but no risk was indicated from soil-derived data, highlighting the value of integrating different SSD approaches for more comprehensive pesticide risk assessments.