不同施肥模式下土壤-玉米中重金属累积规律及安全性分析

Accumulation and Risk Analysis of Heavy Metals in Soil-Maize Cropping System under Different Fertilization

施用化肥(N、P、K)土壤中重金属(Ni、Cu、Zn、As、Pb)仅有少量残留或不残留;农家肥和化肥配施土壤中Cr、Cu、Zn、Cd、Pb出现了累积效应;单施用化肥增加了土壤中的Cr和Cd累积,随着有机肥料的施入使这两种重金属的风险加剧,特别是农家肥和化肥配施更进一步提高了重金属Cr、Cd以及Cu、Zn的风险。施肥可增加Ni、As、Pb在植株中的富集,减少Zn的吸收。单施化肥提高植物体Cd的富集,农家肥和化肥配施可减少Cr、Cu、Cd和Pb向植物体的富集。通过预测,化肥的使用短期内不会存在子粒中重金属超标的危险,农家肥和化肥混施条件下Cr、Zn、Cu超标的预防应该引起注意。

The results showed that with the application of chemical fertilizers（N, P, K） alone, concentrations ofheavy metals（Ni, Cu, Zn, As. Pb） in soils changed insignificantly, but the concentration of Cr and Cd increased. How-ever, in plots amended with chemical fertilizers plus organic manure, concentrations of Cr, Cu, Zn, Cd and Pb in soilsincreased, which might raise potential risk of soil heavy metals contamination, especially the pollution of Cr, Cd, Cuand Zn. Application of fertilizers alone or combined with organic manure led to increment in concentrations of Ni, Asand Pb in maize plant, but the concentration of Zn reduced. The accumulation capacity of Cd in maize plant increasedin plots amended with chemical fertilizers alone, but that of Cr, Cu, Cd and Pb in maize plant decreased significantlywith the combined application of chemical fertilizers and organic manure. It was predicted that short term applicationof chemical fertilizers alone would not result in heavy metals pollution in maize seeds, but it was suggested to pay moreattention to the Cr, Zn and Cu pollution caused by application of chemical fertilizers plus organic manure.