What it is
Researchers tested the effects of 63 pesticides on soil archaea, bacteria, fungi, protists, nematodes, arthropods and key functional gene groups across 373 sites spanning woodlands, grasslands and croplands in 26 European countries. Residues were detected at 70% of sites and emerged as the second strongest driver of soil biodiversity patterns after soil properties. The effects were organism- and function-specific: pesticides altered microbial functions including phosphorus and nitrogen cycling, and suppressed beneficial taxa such as arbuscular mycorrhizal fungi and bacterivore nematodes.
Why it matters
Soil biodiversity is a cornerstone of ecosystem functioning, yet the effects of pesticides on the full soil community and its nutrient-cycling functions are not routinely captured in current risk assessment. Detecting residues at 70% of sites across 26 countries, with pesticides ranking as the second strongest driver of soil biodiversity after soil properties, shows these non-target effects are widespread rather than local.
How to read this
It makes the case for integrating functional and taxonomic soil traits into risk assessment so that regulation safeguards the organisms driving nutrient cycling, not only the intended targets.
Underlined numbers link to their source. See all metrics and figures under Sources below.