Abstract
A study to determine the effects of simulated acid rain on two Canadian Shield podzolic soils was performed on field plots and reconstructed profiles. Soils were irrigated with deionized water and HNO3 and H2SO4 (1:2 molar ratio) solutions at pH 3.5 and 2.0. Pore–water concentrations of Na, K, Mg, Ca, Fe, Mn, and Al were measured at 15–60 cm over 2 years. Half the reconstructed profiles were dismantled after 1 year. Total organic C, exchange cations Ca, Mg, K, and Na, and titratable acidity were measured and three different extraction procedures were used to determine soil free iron and aluminum oxides. Al mobilization high in the profiles, with extreme values up to 40 mg/L at pH 2.0, was followed by redeposition lower in the profile. Up to threefold enhancement of Ca and Al leaching was observed under the most acidic conditions, particularly in the field. Evidence in the present study suggests that anion affinity of the mineral soil reduces the leaching of base cations. A significant decrease in free iron oxides just below the Ae horizon was observed in one of the soils.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
