土壤肥力对其脲酶与汞镉关系的影响  

The Relationship between Urease Activity and Heavy Metals Affected by Soil Fertility

作　　者：和文祥[1] 陈会明[1] 朱铭莪[1] 张一平[1] 

机构地区：[1]西北农林科技大学资源环境学院,杨凌712100

出　　处：《华中农业大学学报》2002年第6期526-530,共5页Journal of Huazhong Agricultural University

基　　金：国家自然科学基金资助项目 (3 93 70 14 8)

摘　　要：对受汞镉污染的不同肥力土壤脲酶活性的测定结果表明 ,汞镉不同程度地抑制土壤脲酶活性 ,其中Hg +Cd的抑制幅度最大。随重金属浓度增加 ,酶活性降低 ,其强度Hg Cd。通过计算得到脲酶生态剂量ED50Hg Cd ,揭示出脲酶对Hg的敏感性远大于Cd。获得 土娄土脲酶ED50 值 :Hg 0 .5 0 8～ 2 .2 4 8mg/kg ,Cd35 0 .0～4 81.0 9mg/kg ,建议将其作为土壤汞镉污染的参考指标。相关分析显示 ,在肥力水平差异较大的土壤上 ,脲酶活性仍可表征土壤受汞镉污染的程度。在复合污染条件下 ,脲酶活性不仅受到单因素影响 ,而且存在汞、镉间弱的拮抗作用 ,但仍以单独效应为主。高肥土壤由于有机质等对脲酶的保护容量较大 ,对重金属的缓冲作用明显 ,导致汞镉对脲酶的生态毒性较弱 。The relationship between soil urease activity and heavy metals affected by fertility was studied. The results showed that mercury and cadmium could inhibited soil urease activity at different degres, Hg+Cd is the most serious.Urease activity decreased with increasing heavy metal concentrations, the decreasing content is HgCd.Soil urease ecological dose ED 50 HgCd, revealed that Hg was more sensitive to urease than Cd. Lou soil urease ED 50 Hg and Cd were 0.508～2.248 and Cd 350.0～481.09 mg/kg, respectively. By correlation analysis, soil urease activity can be an index of soil polluted by Hg and Cd.Urease activity affected not only by single heavy metal, but also by the interaction between Hg and Cd, the effect is still mainly done by single heavy metal.Higher fertility has little ecological toxicity on Hg and Cd because soil sample has high protection enzyme by organic matter and clay, meanwhile heavy metals have more buffering action by organic matter.Lower fertilitiy soil is on the contrary.

关 键 词：土壤肥力 脲酶 汞 镉 重金属 生态毒性 

分 类 号：S154.2[农业科学—土壤学] X54[农业科学—农业基础科学]