【摘要】 采用室内盆栽试验,研究低(N1:110kg/hm2)、中(N2:220kg/hm2)、高(N3:440kg/hm2)3水平的尿素处理对重金属Cd、Pb污染土壤中农作物玉米(Zeay mays L.)幼苗生长及吸收富集重金属Cd、Pb的影响。结果表明:中、高水平的尿素处理能促进玉米生长,玉米总生物量较对照CK(N0:0kg/hm2)显著增加31.92%~55.68%,并能显著增强玉米对重金属的吸收及转运;与CK相比,N2、N3处理的玉米Cd、Pb富集系数增加25.53%~97.51%,除N3处理的玉米Pb转运系数较CK下降8.04%外,玉米Cd、Pb转运系数同步增加13.90%~38.94%。与此相比,低水平尿素处理中玉米的生物量及重金属吸收与CK均无显著差异,N1处理玉米对重金属的吸收及转运低于N2、N3。因此,中、高水平尿素施用量对玉米生物量积累及重金属富集具有显著同步促进效应,在生产实践中应通过权衡玉米经济产量与重金属富集2大指标,通过适度调控施肥措施减少玉米对重金属的吸收,从而保障农产品安全。更多还原

【Abstract】 Nitrogen(N)application was an important factor in heavy metal uptake and accumulation of maize(Zeay mays L.).In order to reveal the effect of nitrogen(N)application on heavy metal uptake and accumulation by maize,pot experiments of four N application rates which were CK(N0:0kg/hm2),low N(N1:110kg/hm2),normal N(N2:220kg/hm2)and high N(N3:440kg/hm2)were conducted.The results showed that:A significant change in biomass and heavy metal uptake and transport of maize under different N application rates.Biomass of maize in N2,N3 treatments were significantly improved which were 31.92% ~55.68% higher than CK,as well as the heavy metal accumulating coefficient and transport coefficient of maize in N2,N3 treatments were 25.53%~97.51% and 13.90% ~38.94% higher than CK respectively.However,Pb transportcoefficient of maize in N3 treatment decreased 8.04% than CK.On the other hand,N1 treatment had no obvious influence on the biomass and heavy metal uptake and transport of maize than CK,and the heavy metal accumulating coefficient and transport coefficient of maize of N1 treatment was lower than N2 and N3.Generally,N application rates of N2 and N3treatments had synchronization promoting effects on improving dry matter accumulation and heavy metal uptake of maize.Thus,the economic yield and heavy metal accumulation of maize in planting practice should be well balanced,then the heavy metal uptake of maize would be reduced which could ensure the safety of agricultural products by modest N fertilizer practice.更多还原