In order to find out the suitable amount of nitrogen fertilizer for rapeseed in phytoremediation

a field experiment was conducted to study the effect of five nitrogen levels (0

90

120

150 and 180 kg/hm2) on the yield

cadmium (Cd) uptake and accumulation of rape (Brassica campestris L.) (Xiangzayou 743 and Fengyou 682). Results showed that the application of nitrogen fertilizer significantly increased shoot biomass of rape. Compared with the control treatment

the shoot biomass of ‘Xiangzayou 743’ and ‘Fengyou 682’ was significantly increased by 473.9%～1 055.5% and 412.4%～1 164.6%

respectively. Nitrogen application increased the uptake of Cd by rape roots and the transport Cd from root to shoot. With nitrogen treatments

Cd concentrations in root of ‘Xiangzayou 743’ and ‘Fengyou 682’ were increased by 1.5%～21.9% and 6.0%～26.3%

respectively

while Cd concentrations in shoot increased significantly by 22.2%～82.8% and 19.5%～45.8%

respectively. Cd accumulation in shoot were increased significantly by 598.5%～1 912.4% and 518.6%～1 547.3%

and the Cd transfer coefficients increased by 1.7%～19.3% and 18.5%～65.1%

respectively. Cd concentration in roots was significantly negatively correlated with soil CaCl2-Cd concentration. The main reason for increasing Cd accumulation in shoot of rape was the increase of bioavailability and the transfer coefficient of Cd. Under this experimental condition

the suitable nitrogen application level for rape in phytoremediation was 150 kg/hm2.