Evaluation of cadmium absorption in different soil textures by black locust (Robinia pseoudoacacia L.), round-leaf ash (Fraxinus rotundifolia Miller) and Arizona cypress (Cupressus arizonica Greene)

Soil pollution caused by cadmium has recently become a major concern. Phytoremediation is a convenient, cost-effective and eco-friendly method for remediation of polluted environments. In this study, the effect of soil texture (clay, clay-loam and silty- clay- loam) on the cadmium accumulation by leaves, stems, and roots of black locust (Robinia pseoudoacacia L.), round-leaf ash (Fraxinus rotundifolia Miller) and Arizona cypress (Cupressus arizonica Greene) was surveyed. The study was carried out in a complete random-based factorial design with four factors (plant species, plant organs, soil texture and cadmium concentration level). At the end of the growing season, the cadmium concentration in the organs was measured. Analysis of variance showed significant deference (P < 0.01) of cadmium absorption amongst the species. Moreover, the three species showed significantly different absorption rate amongst different organs. In addition, different cadmium concentrations (1000, 2000, 3000 and 4000 mg/kg) applied on the species revealed significantly different absorptions. Soil texture was concluded to have no significant effect on cadmium absorption. Furthermore, R. pseoudoacacia revealed the highest absorption level which was attributed to its genetic specifications