Occasional Flooding Impact On Heavy Metals Content In The Soil Of Polder Beša

Three plots in Dry Polder Beša in Slovakia (E) and 3 plots in no flooded area (R) were chosen to assess the Cd, Pb and Ni contamination in the soil by using geo-accumulation index (I_geo) and anthropogenic contribution rate (ACR). Heavy metals content was measured at three depths (0‒0.2 m, 0.2‒0.4 m and 0.4‒0.6 m). It was found that the average content of Pb was 1.4 times higher and content of Ni 2.3 times higher at experimental area than at reference area. The average content of Cd were on the same level (E - 0.040 mg/kg, R - 0.041 mg/kg). The variability of heavy metals content in the soil was significantly influenced by soil depth and sampling plot and concentrations significantly correlated with soil organic carbon content (r - in the range of 0.41 to 0.65, p < 0.05). Geo-accumulation index indicates that the soils in the all of studied plots were polluted with respect to Ni, while were unpolluted with respect to Cd and Pb. Cd and Pb occurrence in these soils may be associated to the geochemical weathering. The value of the ACR indicate that anthropogenic input of Ni was 1.331 times higher in flooded area than in reference no flooded area. Different soil types can be arranged in descending Igeo values for Ni as follows: Luvisols ˃ Regosols ˃ Gleysols ˃ Chernozems. It was found that the content of Ni and Pb exceeded the critical values, in relation to transfer of contaminants from the soil to the plant , only at flooded area.