Pesticide drift into field margins threatens bee pollinators and other beneficial insects

Pesticide drift into sensitive habitats is an increasing concern in agricultural landscapes due to negative impacts on non-target animals including wild bees and other beneficial insects. Creating buffer zones between the crop and sensitive habitats has been commonly proposed as a mitigation measure for reducing off-target pesticide deposition. Given prior evidence of significant pesticide deposition in wildflower plantings adjacent to highbush blueberry farms in Michigan, the aim of this study was to determine the buffer zone needed to significantly reduce pesticide deposition in these plantings. We used silicone bands as passive pesticide samplers placed at varying distances between 0 and 32 m from the crop at conventionally managed blueberry farms during the fruit ripening period when insecticide applications are common. We found there was no significant reduction in number of active ingredients detected in samples at any measured distance from the crop. There was also no significant reduction in pesticide concentration (summed mass of all active ingredients) until 24 m from the field border, and this change was driven by reductions in concentrations of fungicides as there was no significant reduction in total insecticide or herbicide deposition at any of the tested distances. Drift reduction measures, such as installation of windbreaks and use of precision application methods are recommended to reduce off-target pesticide movement.