Uptake of Cd and Ni by spinach, Spinacea oleracea (L.) from polluted soil under field conditions as affected by salt water irrigation

Both heavy metal pollution and soil salinization are increasing in dry area s. Nevertheless, salinity-heavy metal interactions in soils and crops are n ot well understood. This work aimed at evaluating the effect of salt water irrigation on the uptake of Cd and Ni by spinach from a polluted soil under field conditions at the Nahda project site, northwest of Egypt. Microplots were irrigated either with water or with salt solution (0.8 g.L-1) for 9 w eeks. Subsequently, the plants were harvested for root evaluation and plant as well as soil chemical analysis. Salt water irrigation stimulated root d evelopment and enhanced the extractability of Cd and Ni from soil as well a s their uptake by spinach considerably. Possibly related interactions are d iscussed. The results suggest that the risk of leaching of heavy metals int o surface waters and their transfer to the food chain in salt affected area s may be much greater than so far assumed, (C) Inra/Elsevier, Paris.