Cadmium Content and Accumulation in Lettuce Grown on Different Types of Soil

This study was conducted on a pseudogley (pH 5.0) and a vertisol (pH 6.9) to analyze their total and available Cd levels and Cd accumulation by lettuce for risk assessment of potential human health impacts. Total Cd levels in both soil types were below maximum allowable concentrations, and showed a high dependence on soil pH (R=-0.974). Monoammonium phosphate (MAP) fertilizers containing various amounts of cadmium led to an increase in cadmium uptake, with higher concentrations accumulated in lettuce roots than in leaves. The transfer factor showed that Cd uptake from the pseudogley was much higher than from the vertisol, and its values indicated that lettuce is a cadmium hyperaccumulator. Lettuce head weight decreased with increasing cadmium rates and was highly negatively correlated with Cd concentration in the leaves (R=-0.818).