通过等温吸附试验,研究Ca(NO3)2、NH4Cl、NH4NO3、CO(NH2)2、KH2PO4和KCl 6种化肥对土壤中Cu吸附行为的影响。结果表明,添加CO(NH2)2使土壤中Cu的吸附率和分配系数增大,NH4NO3、KCl、NH4Cl和Ca(NO3)2则使其明显减小,KH2PO4对土壤Cu吸附的影响作用与Cu离子浓度有关。不同化肥处理土壤中Cu的吸附势E0顺序为:CO(NH2)2〉CK〉NH4NO3〉Ca(NO3)2〉KCl〉NH4Cl〉KH2PO4。6种化肥对土壤中Cu吸附行为的影响作用为:KH2PO4〉CO(NH2)2〉CK〉NH4NO3〉KCl〉NH4Cl〉Ca(NO3)2。由于不同化肥对土壤中Cu吸附行为的影响不同,因此在Cu含量较高的土壤上种植时应合理选择施用化肥,以避免土壤中Cu的迁移转化,降低其生物有效性。
Six types of fertilizers,i.e.Ca(NO3)2,NH4Cl,NH4NO3,CO(NH2)2,KH2PO4 and KCl,were used in an isothermal adsorption experiment to study effects of fertilizers on Cu adsorption behaviors in soil.Results show that application of CO(NH2)2 increased adsorption ratio and distribution coefficient of Cu,but the application of NH4NO3,KCl,NH4Cl or Ca(NO3)2 demonstrated an obviously reverse effect;the effect of KH2PO4 was related to Cu concentration.Cu adsorption potential E0 varied with fertilizer treatments,following an order of CO(NH2)2 CK(control groups)NH4NO3 Ca(NO3)2 KClNH4ClKH2PO4.The effects of the six types of fertilizers on Cu adsorption behaviors followed the order of KH2PO4 CO(NH2)2 CKNH4NO3 KClNH4ClCa(NO3)2.Because of the different effects of the fertilizers on Cu adsorption,reasonable choice should be made as to what type of fertilizer is to be used during crop cultivation season in the soil high in Cu content in order to avoid Cu mobilization transformation and decrease its bio-availability.