The study looked at how soil pH affects the adsorption and desorption of heavy metals like Cd, Cu, and Zn in different soils. They found that the maximum adsorption of these metals occurred around pH 6.0, regardless of soil type. Cu and Zn adsorption was linked to soil properties like C.E.C. and organic matter. Cu adsorption increased more with soil pH adjustment using Cu application rather than NaOH. Cu was also harder to desorb from certain soils due to their mineral composition and high C.E.C. and organic matter content.