Inferring Mobility of Trace Elements Resulting From Long-term Poultry Litter Additions to Benchmark Alabama Soils

Abstract

Poultry litter when applied to agriculture lands contains high trace element concentrations that may become toxic to plants and pose a risk to surface water and groundwater. We evaluated whole soil elemental concentrations throughout the soil profile using the US Environmental Protection Agency digestion method 3052 for Alabama benchmark soils that had received more than 20 years of poultry litter. Paired soils that had not received poultry litter were equivalently characterized. Pairwise comparison tests indicate that trace element concentrations were significantly greater (P < 0.05) in poultry litter–amended soils than those in nonamended soils. Cadmium, As, Cu, Ni, and Cr concentrations significantly increased with soil profile depth relative to those in nonamended soils. Chromium concentration significantly increased from 38.8 mg kg (0–15 cm) to 116 mg kg (75–90 cm) in Malbis soil. The downward migration of these metals and metalloids may pose a risk to shallow groundwater resources and, if the soil is eroded, may pose a risk to surface water resources.