土壤调理剂与有机肥对Cd污染农田的修复效果研究

Study on the remediation effect of soil conditioner and organic fertilizer on Cd-contaminated farmland

选用土壤调理剂与有机肥在长阳资丘镇受Cd污染地区开展大田试验,分析不同量的土壤调理剂与有机肥对土壤理化性质与总Cd、有效态Cd、玉米Cd含量的影响。结果表明,土壤调理剂与有机肥都能适当提高土壤pH,其中T3、T8、T9处理可以较好地调节土壤pH,且与对照组相比具有显著差异。T4到T9处理与对照组相比能显著提高有机质、有效磷、速效钾、缓效钾的含量。土壤调理剂与有机肥通过调节土壤的理化性质来影响土壤Cd的活性,促使有效Cd向稳定态转化,从而降低玉米对Cd的吸收与积累。相关性分析表明,玉米Cd含量与土壤pH呈显著负相关关系,与土壤有效Cd呈显著正相关关系。从土壤有效Cd和玉米中Cd的降低率考虑,T9处理效果最好,对Cd的钝化效率为21.57%,玉米Cd含量0.039 mg/kg,与对照组相比降低了49.35%。

Soil conditioner and organic fertilizer were used to carry out field experiment in the Cd-polluted area of Ziqiu town,Changyang City.The effects of soil conditioner and organic fertilizer on soil physical and chemical properties,total Cd,available Cd and Cd content of maize were analyzed.The results showed that both soil conditioner and organic fertilizer could increase soil pH value,and T3,T8 and T9 could adjust soil pH value better,and there was a significant difference compared with the control group.The contents of organic matter,available phosphorus,available potassium and slow-acting potassium were significantly increased in the treatment of T4 to T9 compared with the control group.Soil conditioner and organic fertilizer affected the activity of Cd by adjusting the physical and chemical properties of soil,promoted the transformation of effective Cd to the stable state,and thus reduced the absorption and accumulation of Cd by maize.Correlation analysis showed that Cd content of maize was negatively correlated with soil pH and positively correlated with soil available Cd.Considering the reduction rate of Cd in soil and maize,T9 treatment was the best for the passivation of Cd,and the inactivation efficiency of Cd was 21.57%and the content of Cd was 0.039 mg/kg,which was 49.35%lower than that in the control group.