Intact soil cores were collected to a depth of 15 cm from a Lexington silt loam. Simulated precipitation with adjusted pH values of 3.7, 4.7 and 5.7 (control), was applied to the cores in increments of 500 mL day until totals which approximated 10, 20, 40, and 80 yr of effective rainfall in Louisiana were reached. The exchangeable acidity and A1 and H2O and KCl pH were measured from 2.5 cm sections of the cores after treatment. Only the 3.7 treatment at the 80 yr volume significantly affected the soil pH and exchangeable acidity and Al.