钝化剂组合对水稻土Pb、Zn赋存形态及水稻根系富集的影响

Effects of Passivator Combinations on Pb,Zn Forms in Paddy Soil and Their Accumulation by Rice Root System

为筛选出有效抑制Pb、Zn在土壤-水稻根系中积累的有机、无机材料钝化剂组合,选取水稻土,以盆栽试验研究了15种钝化剂组合(生石灰、鸡粪、钝化剂D1—D4,分别构成一元组合、二元组合、三元组合)对水稻土壤Pb、Zn赋存形态及水稻根系富集的影响。结果表明,施用钝化剂后,与CK相比,土壤pH值上升0.25~1.04,土壤阳离子交换量(CEC)增加2.65%~50.96%,有机质(OM)含量上升0.22%~17.20%,土壤总Pb、Zn含量无明显变化。施用钝化剂后,与CK相比,可交换态Pb含量降低14.59%~27.06%,可还原态Pb含量增加7.99%~17.65%,土壤可氧化态、残渣态Pb含量无明显变化。施用钝化剂后,与CK相比,可交换态Zn含量降低12.58%~33.30%,可还原态Zn含量增加1.35%~22.40%,可氧化态、残渣态Zn含量无明显变化。施用钝化剂后,与CK相比,水稻根系中Pb、Zn含量降低,一元、二元、三元组合使水稻根系中Pb含量分别降低8.53%~47.40%、29.09%~52.54%、43.54%~68.97%,一元、二元、三元组合使水稻根系中Zn含量分别降低20.41%~42.39%、6.45%~44.90%、45.40%~57.89%,施用钝化剂后,与CK相比,水稻根系Pb、Zn富集系数分别降低了5.00%~70.00%、4.55%~59.09%。综上所述,施用钝化剂后,与CK相比,土壤Pb、Zn由可交换态向其他形态转化,钝化剂三元组合在降低水稻根系中Pb、Zn含量方面具有较好的效果。

In order to screen out the passivator combinations of organic,inorganic materials which can effectively inhibit the accumulation of Pb,Zn in soil-rice root system,a pot experiment of paddy soil was conducted,to study the effects of15 passivator combinations(quicklime,chicken maure,passivators D1-D4 constituted single combination,binary combination,ternary combination) on combined forms of Pb,Zn in paddy soil and content of Pb,Zn in rice root system.The results showed that,after application of passivators,compared with CK,the soil pH value increased by 0.25-1.04 and cation exchange capacity of soil (CEC) increased by2.65%- 50.96%,content of organic matter (OM) increased by 0.22%- 17.20%,while total content of Pb,Zn in soil had no significant changes.After application of passivators,compared with CK,content of exchangeable Pb reduced by14.59%- 27.06%,content of reducible Pb increased by 7.99%- 17.65%,while content of oxidizable and residual Pb in soil had no significant changes.After application of passivators, compared with CK,content of exchangeable Zn reduced by12.58%- 33.30%,content of reducible Zn increased by1.35%- 22.40%,while content of oxidizable and residual Zn had no significant changes.After application of passivators,compared with CK,content of Pb,Zn in rice root were reduced.Single, binary, ternary combinations decreased content of Pb in rice root by 8.53%- 47.40%,29.09%- 52.54%,43.54%- 68.97%,respectively.Single,binary,ternary combinations reduced content of Zn in rice root by20.41%-42.39%,6.45%- 44.90%,45.40%- 57.89%,respectively.After application of passivators,compared with CK,bioconcentration factors of Pb,Zn in rice root reduced by 5.00%-70.00%,4.55%- 59.09%,respectively.In summary,after application of passivators,compared with CK,exchangeable Pb,Zn in soil transform to other forms,and the ternary passivator combinations have a better reducing effect on content of Pb,Zn in rice root.