Copper sulfate is listed as allowed for use in crop systems in 7CFR 205 for plant disease control, with a restriction that it be used in a manner that minimizes copper accumulation in the soil. It is also listed for use as a micronutrient with a testing requirement for documented deficiency. The petition is for use as an algicide and to control invertebrates, specifically tadpole shrimp in rice production. This material has been historically widely used for organic crop disease control in the US and internationally, but the EU has proposed a complete ban on all copper use scheduled to take effect in May 2002. Reviewers were concerned primarily about effects of this use on the aquatic environment, impact on aquatic organisms, and soil accumulation. Reviewers cited concerns about negative effect on mosquito fish, pond snails, and amphibians at the requested rate of use. The literature indicates that while copper sulfate is relatively immobile in soil and becomes quickly bound or adsorbed to organic or clay fractions in the soil, it is also highly water soluble. Some research indicates this may be of concern in marshland ecosystems subject to flooding and drying conditions. While all three reviewer shared concerns about impact on aquatic organisms, one felt that the use of the material should be permitted with strict limitations. Two reviewers found this material not compatible with sustainable systems and recommended against this use. The petitioner proposes listing for this use, with possible restrictions to limit the use to one application per year not to exceed rates of 10 lbs /acre (copper pentahydrate form)
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