Koskinen W C, Clay S A
USDA-Agricultural Research Service, St. Paul, MN 55108, USA.
Rev Environ Contam Toxicol. 1997;151:117-65. doi: 10.1007/978-1-4612-1958-3_4.
Atrazine persistence and fate are influenced by many factors, the interactions of which are difficult to predict. Several models, such as LEACHP (Wagenet and Hutson 1989), have been used as tools to estimate losses and identify variables that will impact the magnitude of loss. The LEACHP model was evaluated for predicting atrazine movement in sandy loam, silt loam, and clay loam soils during three consecutive years (two dry and one wet) in Minnesota (Khakural et al. 1995). Considering the broad range in soil properties and climatic conditions used in testing, the model performed well. However, these are only estimates, and additional field studies need to be conducted to verify model results. In a report by Fausey et al. (1995), the amount of atrazine found in groundwater throughout the Midwestern region was reported to be much below the MCL. However, specific sites in the Midwest may struggle with atrazine problems from both point and nonpoint sources of contamination. Some states, such as South Dakota, have created groundwater protection areas that alert growers and the public to sensitive areas where contamination may occur because of soil type, depth to groundwater, and distance to public wellheads. Wisconsin has developed a tiered managerial strategy, or zoning approach, in which restrictions are matched to pollution detections (Wolf and Nowak 1996). The USEPA has mandates for states to implement generic management plans to prevent pesticide contamination of groundwater. Chemical-specific plans by states will be required for at least five pesticides, one of which will be atrazine. Best management practices have been and are continuing to be developed to aid the grower in lessening the adverse impacts of atrazine. With continuing research into understanding the problem and developing solutions, and with adaptation of these recommendations by growers, the use of effective, inexpensive herbicides may continue with minimal off-site environmental effects.
莠去津的持久性和归宿受多种因素影响，而这些因素之间的相互作用难以预测。一些模型，如LEACHP（Wagenet和Hutson，1989年），已被用作估算损失和识别会影响损失程度的变量的工具。LEACHP模型在明尼苏达州连续三年（两年干旱和一年湿润）期间，针对砂壤土、粉砂壤土和粘壤土中莠去津的迁移进行了评估（Khakural等人，1995年）。考虑到测试中使用的土壤性质和气候条件范围广泛，该模型表现良好。然而，这些只是估算值，还需要进行更多的实地研究来验证模型结果。在Fausey等人（1995年）的一份报告中，据报道，整个中西部地区地下水中发现的莠去津含量远低于最大污染物浓度。然而，中西部的一些特定地点可能会面临来自点源和非点源污染的莠去津问题。一些州，如南达科他州，已经设立了地下水保护区，提醒种植者和公众注意因土壤类型、地下水位深度和与公共井口的距离而可能发生污染的敏感区域。威斯康星州制定了分层管理策略或分区方法，其中限制措施与污染检测情况相匹配（Wolf和Nowak，1996年）。美国环境保护局已要求各州实施通用管理计划，以防止农药污染地下水。各州将需要针对至少五种农药制定特定化学品计划，其中一种将是莠去津。一直在并将继续制定最佳管理措施，以帮助种植者减轻莠去津的不利影响。随着对该问题的持续研究和解决方案的开发，以及种植者对这些建议的采纳，使用有效且廉价的除草剂可能会继续，同时将对场外环境的影响降至最低。
