DOI: 10.5061/dryad.5vn554c
title: Data from: Organic farming promotes biotic resistance to food-borne human pathogens

description: Farmland biodiversity benefits pollination, biological control and other
 key ecosystem services. Food safety has been seen as an exception to this
 broader pattern, as diverse farmlands attract wildlife that vector
 foodborne human pathogens. Resulting mitigation efforts thus often seek to
 deter wildlife by removing natural habitats, while also excluding
 vertebrate livestock. However, surprising recent evidence suggests that
 farm simplification actually increases the likelihood that produce will be
 contaminated with human pathogens. Here, we consider the possibility that
 intensified agriculture harms faeces‐feeding (coprophagous) beetles and
 bacteria, which could contribute to heightened food‐safety risk. In 70
 commercial vegetable fields spanning the US west coast, using either
 organic or conventional farming methods, we surveyed coprophages both
 above‐ and below‐ground. We also measured removal rates of the faeces of
 Sus scrofa, which vectors foodborne pathogens both as livestock and as
 feral wildlife. Above‐ground, organic farms fostered dung beetle species
 that removed S. scrofa faeces more rapidly than was seen on conventional
 farms, although this benefit was weakened in simplified landscapes
 dominated by pasture and an introduced dung beetle. Below‐ground, organic
 farming encouraged significantly higher biodiversity among soil bacteria.
 Organic farming similarly benefitted dung beetles and bacteria on farms
 that produced livestock alongside vegetables, or vegetables alone.
 Complementary laboratory experiments revealed that the dung beetle species
 and biodiverse bacterial assemblages typical of organic farms were
 significantly more effective at suppressing human‐pathogenic Escherichia
 coli O157:H7, compared to coprophage communities associated with
 conventional farms. This suggests that farm management practices,
 coprophage conservation, and human–pathogen suppression might be linked.
 Synthesis and applications. Altogether, our results indicate that insects
 and microbes can rapidly remove faeces, with the potential to also
 decrease the persistence of human pathogens. In turn, this suggests that
 improved food safety may be an important, and perhaps underappreciated,
 ecosystem service that is enhanced by on‐farm biodiversity. We recommend
 that farm managers and regulators consider the risks and benefits to
 coprophages when making management decisions regarding food safety.
description: Data S1 - Beetle
 speciesDung beetles caught in
 baited pitfall traps at each study site during 2014-15 field survey. The
 most common species (Onthophagus taurus, Onthophagus nuchicornis, Aphodius
 pseudolividus) were chosen to use in laboratory
 experiments.Data_S1.xlsxData_S2 Soil PropertiesSoil Properties. Results of soil chemical/physical properties from soil sampling at each study site during 2014-15 field survey.Data_S2.xlsxData_S3 Grassland CoverPercept grazeable grassland cover around each sampling location with spatial location (county-level) at each study site during 2014-15 field survey.Data_S3.xlsx