镧施用下黄潮土酶活性的动态变化

通过模拟试验研究了镧施用下黄潮土酶活性的动态变化。土壤脱氢酶、碱性磷酸酶、脲酶及蔗糖酶活性均随培养时间延长而降低。镧强烈抑制土壤脱氢酶活性 ,在 3 0mg/kg时达到显著水平 (P <0 0 5 ) ,最大抑制率达到 3 9%。镧对土壤碱性磷酸酶活性也有抑制 ,最大抑制率为 1 5 %。镧对土壤脲酶活性影响不明显。镧对土壤蔗糖酶活性表现出不同程度的刺激作用 ,最大刺激率达到 1 5 %。土壤脱氢酶活性是评价稀土元素环境效应的敏感指标。

Dynamic Changes in Enzyme Activity in Fluvo-aquic Soil under Application of Lanthanum

Dynamic changes in enzyme activity in fluvo-aq uic soil under application of lanthanum (La) was studied through simulation expe riments.The activities of soil dehydrogenase,alkaline phosphatase, urease and su crase decreased with the time of incubation.La inhibited strongly the activity o f soil dehydrogenase,and to a significant level (P<0.05) with a maximum inh ibition ratio reaching up to 39% when its concentration was over 30 mg/kg.La als o showed an inhibitory effect on the activity of soil alkaline phosphatase and a maximum inhibition ratio of 15%.But its effect on soil urease was not as signif icant.It stimulated the activity of soil sucrase to a varying degree,with the ma ximum stimulation ratio being 15%.Consequently,the soil activity of dehydrogenas e can be taken as a sensitive index for assessing environmental effect of rare e arth elements.