Effects of Cd on Uptake of P in Potato Grown in Sierozems

The effects of Cd on the bioaccumulation of P in soil-plant system have aroused wide interest and been widely explored. Sierozem has been contaminated by Cd in many areas in Northwest China. To investigate the effects of Cd on the uptake and translocation of P in plants in sierozem, pot experiments were carried out by cultivating potato (Solanum tuberosum L.) under Cd treatment. The fractions of Cd in the soil were examined by soil extraction; available P in the soil was determined; Cd and P accumulation in the plants was also determined. The result of the soil extraction shows that the acid-soluble Cd fraction gradually became the main fraction with the increasing Cd concentrations in the soil. This suggests that the change in the main fraction of Cd may promote the uptake of Cd in plants because acid-soluble Cd fraction may be utilized easily by plants. Given increasing Cd concentrations in the soil, Cd concentrations increased in each part of potato plants, whereas the soil available P and plant P contents were decreased. These results indicate that increasing Cd concentrations in sierozems exerts negative effects on the uptake and translocation of P in plants.