Effects of Swine Effluent On Leaching of Ammonium and Nitrate in Soil.

The use of agricultural land as an alternative for swine effluent disposal have some agronomic benefits, however, it may pollute groundwater due to the leaching of ammonium and nitrate, even in oxidic soils. The objective of this study was to evaluate the effect of swine effluent on the leaching of nitrate and ammonium in a dystroferric Red Latosol (DRL), a dystrophic Yellow-Red (YRL), and a dystrophic Yellow-Red (YRA).  Samples of these soils (0-100cm depth) were packed in 10cm-diameter and 100cm-length columns. Lime was applied to increase base saturation to 70%, and 4L of deionized water was applied to each column in order to increase soil moisture and allow the lime to react. After 15 days, 1 liter of deionized water (DW), swine effluent (SE) or ionic solution (IS) was applied weekly, for ten weeks. Higher amount of ammonium was found in the leachate of IS columns, regardless of the soil type. More ammonium was found in the leachate of YRL soil, followed by DRL and YRA soils, regardless of the applied material. The SE treatment caused higher amounts of nitrate in the column effluent from YRL and YRA soils, as compared to the IS treatment. The leachate from DW columns showed the lowest amounts of nitrate. The leachate from YRA columns had lower amount of nitrate than the effluent from YRL and DRL soils.