During herbicide spray application, nontarget terrestrial plants (NTTPs) growing in the off‐field area need to be protected from unacceptable effects of herbicide drift. The risk of such unintended effects is assessed in order to establish whether a particular use can be approved, possibly in combination with mitigation measures. In Europe, the risk of herbicide treatment to NTTPs is assessed on the basis of tier 2 studies done under controlled conditions in greenhouses. Following the concept of a tiered testing approach, higher tier field studies under more realistic conditions could be used to refine the risk assessment. No current guideline for conducting higher tier NTTP field studies is available. We developed an NTTP higher tier field study method done on an experimental plant community established by sowing of a seed mixture. The setup was optimized in 3 pilot field studies and subsequently used for a definitive study testing effects of the herbicide iofensulfuron‐sodium. Results show that the method can be regarded as a suitable higher tier option for assessing effects of herbicides on NTTPs. Growth of species from the soil seed bank cannot be avoided and has to be carefully considered when evaluating results. Adaptations of the study design may be necessary when testing different herbicides. Community‐level endpoints were at the same level as single‐species endpoints. Results of the field study were compared to standard greenhouse study results for the same herbicide. No observed effect rates (NOERs) in the field were about a factor of 10 higher and show that the current tier 2 risk assessment for NTTPs can be regarded as protective in this case. Whether the present field study design and the assessed endpoints can be used in higher tier risk assessment of NTTPs depends on selection of the specific protection goal and requires further discussion. Integr Environ Assess Manag 2020;16:691–705. © 2020 Bayer AG. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC)

中文翻译：

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一种田间研究方法，作为潜在的高级方法，用于完善非目标陆生植物的除草剂风险评估

在喷洒除草剂期间，需要保护在野外地区生长的非目标陆地植物（NTTP），以免受除草剂漂移的不良影响。为了确定是否可以批准某种特定用途（可能与缓解措施结合使用），评估了这种意外影响的风险。在欧洲，根据在温室中受控条件下进行的第2级研究评估了对NTTP进行除草剂处理的风险。遵循分层测试方法的概念，可以在更现实的条件下进行更高级别的现场研究来完善风险评估。当前没有进行更高级别的NTTP现场研究的指南。我们开发了一种通过种子混合物播种建立的实验植物群落的NTTP更高层田间研究方法。该设置在3个试验现场研究中进行了优化，随后用于确定性研究，以测试除草剂碘芬磺隆钠的作用。结果表明，该方法可作为评估除草剂对NTTP效果的合适的更高层次的选择。无法避免土壤种子库中物种的生长，在评估结果时必须仔细考虑。测试不同的除草剂时，有必要对研究设计进行修改。社区级别的端点与单物种的端点处于同一级别。将野外研究的结果与相同除草剂的标准温室研究结果进行比较。在该领域，没有观察到的有效率（NOER）大约高出10倍，并且表明在这种情况下，当前对NTTP的第2级风险评估可以被视为具有保护性。Integr环境评估管理2020； 16：691-705。©2020拜耳公司。Wiley Periodicals，Inc.代表环境毒理化学协会（SETAC）出版的《综合环境评估与管理》