Effects of Graded Levels of Cadmium on Spinach and Cabbage Grown in an Inceptisol

Cadmium (Cd) contamination of the soil and its concentrations in spinach and cabbage were studied in a pot culture experiment. Eight levels of Cd (0–100 mg kg−1 soil) were applied singly. Application of Cd of up to 10 and 15 mg kg−1 resulted in safe Cd concentrations (1.56 and 1.38 mg kg−1) in the shoots of spinach and cabbage, respectively, at the consumable stage. The total chlorophyll content gradually decreased with the addition of Cd, and the maximum decreases were 31.7 and 32% in spinach and cabbage, respectively, at 60 days of crop growth in the treatment Cd100 over the control. The greatest diethylene triamine penta-acetic acid (DTPA)–extractable Cd contents in the postharvest soil of spinach and cabbage were 22.09 and 24.22 mg kg−1, respectively, in the treatment Cd100. The DTPA Cd was significantly negatively correlated with leaf area and total chlorophyll content while positively correlated with root and shoot Cd concentrations of spinach and cabbage.