猪粪和石灰对铅锌尾矿污染土壤中紫花苜蓿生长及重金属吸收特性的影响

Effects of organic manure and lime on growth and heavy metals accumulation in Alfalfa grown in soil polluted by lead/zinc mine tailings

通过温室盆栽试验,研究了铅锌尾矿污染土壤上施用有机肥、石灰2种改良剂对紫花苜蓿生长发育、产量、叶绿素含量以及重金属元素Cu、Cd、Pb、Zn积累特性的影响,并分析施用改良剂后土壤pH值和土壤中有效态重金属含量的变化。结果表明,与对照(不施加任何改良剂)相比,2种改良剂的不同施用水平均能不同程度地提高土壤pH值,显著降低土壤中各重金属有效态含量,明显抑制Cd、Pb、Cu、Zn向紫花苜蓿地上部转移,降低重金属在紫花苜蓿地上部植株中的积累,改善紫花苜蓿的生长和发育,株高、地上部鲜重和地下部鲜重、叶绿素含量均有不同程度的增加;2种改良剂的不同处理水平对紫花苜蓿地下部重金属含量的影响均达到显著水平。总体上看,当有机肥、石灰的施用量均为10g/kg土时,其改良土壤的效果最明显。

The present study has been conducted to study the effects of organic manure and lime amendment on the growth, development, yield, chlorophyll content and accumulation of heavy metals （Cu, Cd, Pb and Zn） in Alfalfa grown in pot culture having soils contaminated by mine railings containing lead and zinc. The changes in pH and its effect on available heavy metal content in soil were also investigated. The results showed that beth amendments could significantly increase pH and decrease the content of available heavy metal in soil. It was found that the translocation of Cd, Pb, Cu and Zn from root to shoot of Alfalfa was inhibited by application of organic manure and lime that resulted in the reduction of heavy metal accumulation in above ground parts of Alfalfa. Application of amendments could significantly improve the growth and development of Alfalfa and increase the plant height and fresh weight of abeveground and underground parts and chlorophyll content in leaves of Alfalfa. Significant differences in heavy metal content have been observed with application of different levels of organic manure and lime amendments. The best effect was observed with the amendment of 10g/kg soil organic manure and 10g/kg soil lime.