Abstract
Recent increases in rainfall acidity and intensity have generated interest in their effect on soil-bound ions (i.e. mineral cations or nutrient anions) in drainage. A soil column experiment was conducted under field conditions to characterize infiltrated soil water quality resulting from simulated rainfall treatments. Two rainfall treatments (neu-tral rain and acid rain) and four rainfall intensities (2, 4, 20, 80 mm hr−1) were investigated. Water draining through the soil column was sampled and analyzed for electrical conductivity (EC) and dissolved ion concentration. Re-sults showed the acidic rain treatment caused more solute discharge than did neutral rain treatment. Infiltrated soil water quality was much higher than rain water, suggest-ing that changes in ionic concentration are due to leach-ing processes rather than ion exchanges. Moreover, high-est solute concentrations was resulted from 80 mm hr−1 rain, being affected by rainfall intensity. Surprisingly, 80 mm hr−1 intensity when combined with acid rain treatment caused higher discharge solute concentrations than either treatment independently.
