Abstract: A soil column experiment and BCR sequential extraction were applied together to investigate the chemical forms and migration risk of zinc （Zn）， copper （Cu）， lead （Pb） and cadmium （Cd） in the farm land soil. It was shown that application of different organic fertilizers had minimal effect on migration of heavy metals. After 9 months flooding， Zn， Cu， Pb and Cd migrated from the topsoil （0—20 cm） down about 2 cm （focusing on 20—22 cm soil layer）， which indicated limited pollution to the deep soil layers. After adding organic fertilizers， with the increase of flooded time， the percentage of acid\|extractable fraction decreased， while the reducible fraction increased， which indicated that organic fertilizers had certain inhibition effect on availability of heavy metals. The content of oxidizable and residual fraction remained substantially constant during this process， and the total percentage of oxidizable and residual fraction was less than 15%.

Key words: flooding, organic fertilizer, soil column, BCR, heavy metal, soil