Ion fluxes leached from each horizon were calculated by multiplying water fluxes by ion concentrations in precipitation (or
throughfall in the MG plantation) and soil solution. The water fluxes of precipitation and throughfall were measured using a
precipitation collector, while the half-hourly fluxes of soil water were estimated by applying Darcy’s law to the unsaturated
hydraulic conductivity and the gradient of the hydraulic heads at 0–5, 10–15, and 40–45 cm depths. The one dimensional, vertical flow equation (Richards’ equation) in the unsaturated soil zone was written as