Quantification of Trace Elements fluxes (As, Cd, Cu, Pb, Zn) into agricultural fields amended with pig slurry

Abstract : The accumulation of trace elements in agricultural soils may have long-term implications for quality of crops. Pig slurry is known as a major source of copper or zinc, because these elements are supplemented in pig feed. But the inputs in arsenic, cadmium or lead are not well quantified. The aims of our study were to quantify the trace elements inputs by pig slurry spreading, to compare them to other sources and to estimate the balances. This analysis was performed on 24 fields located in the South-West of France. Copper and zinc fluxes from pig slurry corresponded to 90 % of the total input fluxes. Soils accumulated these elements with an annual increase of the metal stock equal to 0.5 % for copper and 0.3 % for zinc. For cadmium, the major source was the phosphate fertilizers (60 % of the total inputs). Accumulation of As and Cd in soils was low (2,6 g/year/ha and 1,2 g/year/ha respectively). The major contamination source for lead was the atmospheric inputs.