The pot experiments were performed to investigate the effects of nitrogen fertilizer forms(NH+4-N and NO-3-N) on growth and Pb accumulation characteristics of Picris japonica Thunb.under Pb stress(2 000 mg/kg).The results indicated that,under the Pb stress,a moderate nitrogen fertilizer could be beneficial for the growth of Picris japonica Thunb.and its accumulation capacity for Pb.On the contrary,the growth of Picris japonica Thunb.and the Pb accumulation could be inhibited with an excessive nitrogen ferti...