Soil acidity reflects the balance within the soil’s cation exchange complex between hydrogen ions and acidic forms of aluminium on the one hand and basic metal ions on the other.
Mae asidedd pridd yn adlewyrchiad o’r cydbwysedd sydd o fewn cymhlyg cyfnewid catïon rhwng ionau hydrogen a ffurfiau asidig o alwminiwm ar yr un llaw ac ionau metel sylfaenol ar y llaw arall.