Data from: Agricultural practices for food safety threaten pest control services for fresh produce

Over the past decade, several foodborne disease outbreaks provoked widespread reforms to the fresh produce industry. Subsequent concerns about wildlife vectors and contaminated manures created pressure on growers to discontinue use of manure-based composts and remove nearby semi-natural vegetation. Despite widespread adoption, impacts of these practices on ecosystem services such as pest control have not been assessed.
We used a landscape-scale field experiment to quantify associations between compost applications, semi-natural vegetation, pest control services and lettuce yields on organic farms throughout California's Central Coast, a region experiencing food safety reforms.
We found that farms with surrounding semi-natural vegetation supported a diverse arthropod assemblage, whereas a herbivore-dominated assemblage occupied farms in simplified landscapes. Moreover, predatory arthropods consumed more herbivores at sites with more surrounding non-crop vegetation and reduced aphid pest infestations in lettuce.
Compost improved lettuce yields by increasing soil nutrients and organic matter, but affected neither pest control nor Escherichia coli prevalence.
Synthesis and applications. Food safety concerns are prompting practices that simplify farms and landscapes. Our results demonstrate that two practices – elimination of manure-based composts and removal of non-crop vegetation – are likely having negative impacts on arthropod biodiversity, pest control and soil quality. Critically, our findings and previous research suggest that compost can be applied safely and that habitat removal is likely ineffective at mitigating food safety risk. There is thus scope for co-managing fresh produce fields for food safety, ecosystem services, and biodiversity through applying appropriately treated composts and stopping habitat removal.

过去十年间，多起食源性疾病暴发（foodborne disease outbreaks）引发了鲜食农产品产业（fresh produce industry）的全面改革。此后，针对病媒野生动物（wildlife vectors）与受污染粪肥（contaminated manures）的担忧，迫使种植者停用粪肥基堆肥（manure-based composts），并移除农场周边的半自然植被（semi-natural vegetation）。尽管此类措施已得到广泛推行，但其对害虫防治（pest control）等生态系统服务（ecosystem services）的影响尚未得到评估。
我们依托景观尺度野外实验（landscape-scale field experiment），对正推进食品安全改革的加利福尼亚中央海岸地区全境有机农场（organic farms）中，粪肥施用、半自然植被、害虫防治服务与生菜产量之间的关联进行了量化分析。
研究结果显示，周边保留半自然植被的农场孕育了多样的节肢动物群落（arthropod assemblage），而景观简化的农场则分布着以植食性动物占优势的群落（herbivore-dominated assemblage）。此外，在周边非作物植被更为丰富的样点，捕食性节肢动物（predatory arthropods）对植食性动物的捕食量更高，同时有效减轻了生菜田的蚜虫虫害（aphid pest infestations）。
粪肥基堆肥可通过提升土壤养分与有机质含量改善生菜产量，但既未对害虫防治效果产生影响，也未改变大肠杆菌（Escherichia coli）的检出水平。
综合与应用。食品安全方面的担忧正催生简化农场与景观的实践。我们的研究结果表明，停用粪肥基堆肥与移除非作物植被这两项措施，可能会对节肢动物生物多样性、害虫防治能力与土壤质量造成负面影响。至关重要的是，本研究与既往相关研究均证实，经妥善处理的粪肥基堆肥可安全施用，而移除生境对降低食品安全风险并无实效。因此，通过施用经妥善处理的粪肥基堆肥并停止移除生境，我们能够在鲜食农产品田块中协同兼顾食品安全、生态系统服务与生物多样性保护。