The researchers studied how adding or removing calcium carbonate affects the way soils absorb and release cadmium. They tested three different types of soils and found that adding calcium carbonate increased the amount of cadmium absorbed by the soil. This increase varied depending on the type of soil. Removing calcium carbonate from the soil decreased the amount of cadmium absorbed and increased the amount released. The study showed that calcium carbonate plays a significant role in the adsorption and desorption of cadmium in soils.