The research aimed to investigate the effects of different cadmium (Cd) concentrations (0, 15, 75, and 150 mg•kg⁻¹) using cadmium chloride (CdCl₂) on seed performance, growth characteristics, and the physiological and biochemical traits of fava bean (Vicia faba L.). The results showed that cadmium (Cd) contamination had no significant effect on seed performance. However, vegetative growth properties, including plant height, stem diameter, leaf area, and the percentage of nodule dry matter, decreased as Cd concentrations increased. Interestingly, a low Cd concentration (15 mg•kg⁻¹) slightly improved morphological growth, whereas a higher concentration (150 mg•kg⁻¹) significantly reduced these characteristics. The number of nodules per plant also decreased with increasing Cd levels (15, 75, and 150 mg•kg⁻¹) compared to the control. In contrast, cadmium (Cd) application had no significant effect on leaf number, root length, root diameter, or the dry matter of both shoots and roots.

Regarding physiological and biochemical characteristics, cadmium (Cd) contamination had no significant impact on chlorophyll a, chlorophyll b, peroxide levels, ascorbic acid, total proline, or total carbohydrates. The concentrations of Cd did not significantly alter the leaf content of photosynthetic pigments or the activity of certain enzymatic and non-enzymatic antioxidants. However, catalase enzyme activity and total carotenoid levels significantly increased at 15 mg•kg⁻¹ compared to other treatments. Furthermore, cadmium exposure had no significant effect on stomatal characteristics, including stomatal number, length, and width on both the adaxial and abaxial surfaces of V. faba plants. These findings suggest that while low Cd concentrations may have minimal or slightly beneficial effects on some growth traits, higher Cd levels negatively impact key growth and biochemical parameters in fava beans.