Heavy metals concentration in soil, plant, earthworm and leachate from poultry manure applied to agricultural land

Abstract

Heavy metals of livestock wastes (poultry manure) were studied. Heavy metals from two types of poultry manure (sawdust and straw bed) may represent a potential environmental risk for surface and groundwater. The test was made using a terrestrial microcosm, the Multi-Species Soil System (MS3) developed in the Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA, National Institute for Agricultural and Food Research and Technology). The results of heavy metals in soils showed higher statistically significant differences (p ≤ 0.001) for Zn and Cd in straw and sawdust poultry manure amended soil. In the case of, Cd, Pb and Hg values were increased also for straw and sawdust poultry manure but did not show statistically significant differences. The presence of heavy metals, in the aerial parts of the wheat plant (Triticum aestivum), was studied and only Cu (sawdust poultry manure) and Hg (straw poultry manure) showed statistically significant differences (p ≤ 0.01 and p ≤ 0.05 respectively). The concentrations of Cd, Cu, Zn and Hg in earthworms showed significant differences (p ≤ 0.01, p ≤ 0.05 and p ≤ 0.001 respectively). Cu concentration showed significant differences (p ≤ 0.01) for straw poultry manure only. Finally, regarding the presence of metals in the leachates, only zinc, copper and nickel at 0 and 12 days showed statistically significant differences (p ≤ 0.0001) between control and the different types of poultry manure. For copper and nickel also differences were observed at 12 days.