The researchers studied how copper and zinc behave in sandy soils from citrus groves in Florida. They found that lower soil pH led to more copper and zinc being easily extracted. In one type of sand, the release of these metals increased after reaching certain levels. When the soil had higher copper and zinc levels, more of these metals were found in the leachates. The study showed that the acidity of the soil played a big role in how easily copper and zinc could be extracted and moved around.