Zinc Leaching Potential in Pastureland

Soil liquid phase (soil solution) is considered as an early environmental indicator forpotential leaching of trace elements through soil profile. Field-based sampling for soluble fractions ofnutrients and/or heavy metals like zinc below the root zone is often used to assess potential risk togroundwater. This study was conducted to assess zinc content and seasonal dynamics in a grassland system inNorth Florida. Suction cup lysimeters were installed beneath pasture plots in three replications bydepths at 0.61, 1.22 and 1.83 m at the University of Florida Santa Fe Beef Cattle Research Unit. Themonitoring scheme was designed in a way to permit assessment of the aftereffect of sludge appliedon some of the plots six years earlier. Soil solution samples were taken biweekly, analyzed for pHand zinc content and monthly data averaged as one aggregate observation per plot at each depth. The preliminary results have shown that the zinc content in soil solution was significantly (p<0.05)affected by the treatment and the time of observation and an increase with the depth layers wasobserved. Further information over an extended period, is needed to determine potential long termimpacts on ecological health and groundwater quality.