During my field visits to Mercer County organic farms, growers often express concerns about negative soil health impacts from copper based fungicides. In an effort to evaluate soil copper use and the resulting soil copper levels, soil was sampled at fifteen farms throughout the state.
Soils sampled for copper levels.
Both conventional and organic farms participated in this study which was funded by The Phillip Alampi Fund. Two composite samples were taken from each farm, one where copper fungicides had been applied and one where copper fungicides had never been used. Total and soluble copper levels were higher on copper applied soils compared to the non-copper applied soils. Even though copper levels were higher in these soils, the levels were not high enough to cause plant toxicity symptoms, reduce plant growth, nor were the soils showing signs of reduced microbial activity.
Best management practices developed for copper based fungicides use:
