The study looked at how copper and zinc move in sandy soils. They found that copper mainly comes from certain soil fractions in long-term leaching, while zinc comes from a different fraction. Short-term leaching releases copper and zinc from other fractions. pH levels greatly affect how much zinc and copper are released. Water-logging after rain can increase copper and zinc release. More rain can increase total release amounts but decrease concentration in surface runoff. Calcium in soil can stabilize organic matter and decrease copper release, while high sodium can increase organic matter dissolution and copper release.