铝和镉及其复合污染对砖红壤酶活性的影响

The Influence of Aluminum and Cadmium Pollution on Soil Enzyme Activities in a Latosol

通过土培盆钵试验,研究铝、镉及其交互作用对砖红壤酶活性的影响,并进行相关性分析。结果表明:在铝单独处理中,脲酶活性变化很大;铝抑制磷酸酶、过氧化氢酶、脱氢酶和蔗糖酶活性。镉浓度不超过20 mg/kg时,脲酶活性升高,低浓度镉处理降低磷酸酶活性,而高浓度镉对磷酸酶活性没有影响;镉对过氧化氢酶的影响小于铝。铝与磷酸酶和过氧化氢酶呈显著负相关;铝镉复合处理对脲酶没有交互作用,对磷酸酶、过氧化氢酶、蔗糖酶及脱氢酶的影响有交互作用。由于土壤磷酸酶及过氧化氢酶对不同铝浓度表现出强烈的敏感性,因此选用磷酸酶和过氧化氢酶作为外源铝污染土壤的指示酶。相对其它土壤酶,脲酶对不同土壤镉浓度反应敏感,可以用脲酶作为土壤镉污染的指示酶。

A pot experiment was carried out to evaluate the response of soil enzyme activities to different level of aluminum（Al） with cadmium（Cd） in latosol.The results indicated that urease activity fluctuated strongly under Al stress.Al application inhibited phosphatase,catalase dehydrogenase,invertase activities; Urease activity increased when the Cd concentration was less than 20 mg/kg,phosphatase activity decreased when exposed to low concentration of Cd stress,whereas phosphatase activity was not influenced by high concentration of Cd,the influence of Cd on the catalase was less than that of Al.Through correlation analysis,phosphatase and catalase activities were negatively and significantly correlated with Al,Al/Cd combination had the interaction on phosphatase,catalase,invertase and dehydrogenase.Because the phosphatase and catalase showed strong sensitivity to Al with increasingly concentrations,phosphatase and catalase could be used as the indicator of Al pollution.Compared with the other soil enzymes,urease was sensitive to different Cd concentrations,which could be used as the indicator of Cd contamination.