The study looked at how copper sticks to different types of soil when the soil is acidic. They found that copper sticks quickly at first, then slows down. The amount of copper that can stick to the soil decreases as the acidity increases. The time it takes for half of the copper to stick varies between the soils. The soil releases or consumes hydrogen ions during the process, which can affect how copper behaves. The soil minerals also play a role in the process. The researchers used different equations to describe the reactions, with some working better than others.