尿素对玉米不同时期重金属Cu、Zn和Cd吸收的影响

Influence of Urea on the Uptake of Cu,Zn and Cd of Corn at Different Stages of Growth

通过盆栽试验研究污染红壤中施用不同用量尿素(0,100,200,400mg/kg)对玉米不同时期吸收重金属Cu、Zn和Cd的动态影响。结果表明:玉米生物量随着尿素施用量的增加而增加,且高用量尿素(400mg/kg)处理玉米生物量远高于其他处理。与对照相比,低中用量尿素(100mg/kg和200mg/kg)处理的根区土壤有效态重金属Zn、Cd含量随尿素用量的增加呈增大趋势,但对于高用量尿素处理呈现减小趋势。在玉米生长的60d里,随着生长期的延长,尿素不同处理玉米植株体内重金属含量有逐渐增加的趋势,同一时期尿素高用量处理下玉米植株体内重金属含量低于中低量尿素处理,但是由于获得高生物量使得高用量尿素处理玉米的地上部和根部重金属Cu、Zn、Cd移除总量最高。因此,酸性土壤上高用量尿素的施用,可强化玉米植株从污染土壤中移除重金属的能力。

The effect of applying different urea levels（0,100,200,400 mg/kg） on the uptake of Cu,Zn and Cd of corn at different stages of growth was studied in contaminated red soil by a pot experiment. The results showed that corn biomass increased with the increase of urea application amount,and high application rate of urea treatment（400 mg/kg）of corn biomass was far higher than the other treatments. Compared with con- trol, the root zone soil available heavy metal concentrations of the low and medium amount of urea treatments （100,200 mg/kg）increased with the increase of the dosage of urea, however,the soil available heavy metal concentrations of root zone in high application rate of urea treatment decreased. During the corn growth for 60 days, the heavy metal concentrations in corn increased gradually in different urea treatments with the extension of the growing season. For the same growing period of corn, heavy metal concentration in corn for high application rate of urea treatment was lower than that of low and medium amount of urea treatments. But due to the highest biomass in all treatments,corn in high application rate of urea treatment removed the maximum of copper, zinc and cadmium from the soil. Therefore, high amount of urea application in acidic soils strengthened the corn ability to remove heavy metals from contaminated soil.