Assessment of the potential for phytoremediation of cadmium polluted soils by various crop rotation patterns based on the annual input and output fluxes.

Abstract Phytoremediation potential of two oil crop rotations (oilseed sunflower–rape (O+Ra) and peanut–oilseed rape (P+Ra)) was compared with three conventional cropping patterns (rice–rape (R+Ra), rice–rice (R+R), single cropped rice (SR)) in experimental plots with cadmium (Cd)-contaminated soil. A new approach was used to evaluate phytoremediation potential based on the balance between annual input and output fluxes of Cd in farmland soil. In O+Ra and P+Ra rotations, 77.24 and 62.09 g/ha Cd were removed, respectively, whereas in R+Ra, R+R, and SR patterns, 41.79, 46.46, and 23.85 g/ha Cd were removed, respectively. The balance between inputs and outputs of Cd was − 40.72 and − 25.76 g/ha under O+Ra and P+Ra rotations, respectively. Available Cd content in topsoil was reduced by 5.58% and 3.91% under O+Ra and P+Ra rotations, respectively. Based on the balance between Cd inputs and outputs, phytoremediation efficiencies of O+Ra (1.23%) and P+Ra (0.78%) rotations were higher than those of R+R (0.29%), R+Ra (0.13%), and SR (− 0.38%) systems. Because crop removal is the main Cd output pathway, selection of a suitable crop is particularly important in remediation of Cd-contaminated farmland.