Effects of full and limited irrigation and contaminated soil on cadmium uptake by corn

Abstract

Using plants for the remediation of soils contaminated with heavy metals is an economical, cheap, and effective strategy. The goal of this research was to study the effect of sewage sludge and drought stress on the remediation of cadmium in soil, root uptake by corn plant. This study was carried out on corn in factorial design experiment based on completely randomized design with three replications in three soil pollution levels, namely B1(control soil), B2 (Cd with soil, 20 mg.kg-1), B3 (Cd with sewage sludge with soil treated, 20 mg.kg-1), and two different irrigation regimes, including A1 (full irrigation) and A2 (limited irrigation). The research included two irrigation treatments at two levels of irrigation: 100% of field capacity (A1) and deficit irrigation at 80% of field capacity (A2). The results showed that the soil treated with cadmium and sewage sludge decreased dry and fresh wet weight plant. Sewage sludge increased the amount of cadmium concentration in shoot almost 21% toward the soil treated with cadmium (soil without cadmium); however, it could not increase cadmium uptake due to the decrease in shoot and root dry matter. In limited irrigation, cadmium concentration in shoot and root was reduced by 46 and 16% toward control treatment, respectively. With increasing irrigation and in the soil treated with sewage sludge, the transfer factor of cadmium from root to shoot dry matter increased. The translocation factors were 0.65, 0.5, and 0.13 for sewage sludge contaminated treatments, cadmium-contaminated treatments, and control treatments, respectively. Based on the results, growing plants at an irrigation level of 100% offered nest advantages in terms of higher biomass and efficient Cd removal.