Characteristic of Transformation and Migration of Cu and Zn in Different Black Soil Farmland

Pot experiments were conducted to study the transformation and accumulative rules of Cu and Zn on soybean in the Black soil and the relationship between adsorption and desorption of Cu and Zn in the soils.With the increased concentration of Cu and Zn in the soil,the accumulation of Cu and Zn in aboveground of soybean increased but plant absorption decreased.There was a highly positive correlation between the accumulation of Cu and Zn in aboveground of soybean and the Cu and Zn in the soil.Contents in the aboveground of soybean showed the order of Hailun Black soil > Fangzheng Black soil > Shuangcheng Black soil when put the same concentration of Cu and Zn in the soil.The absorption of Cu and Zn in Black soil of Shuangcheng was higher than that of Fangzheng and Hailun,thus leading to reduction in transferring content of Cu and Zn to the aboveground of soybean.With the increased Cu and Zn addition into the soil,the effective Cu and Zn residues increased in the soil,and the content of Cu and Zn in the plant was also increased.The effective Cu residues in the soil and the addition of Cu into soil were positively correlated.The content of Zn in the plant was higher than the effective Zn residues in the soil with the same concentration of Zn in the soil.