杀虫双对土壤酶活性影响的研究

Study on soil enzyme activity effected by dimehypo

采用模拟方法探讨了杀虫双污染土壤酶活性的变化规律。结果表明 ,杀虫双对土壤脲酶、多酚氧化酶和过氧化物酶具有明显的抑制作用 ,在低浓度时酶活性抑制幅度较大 ,高浓度时抑制幅度较小。土壤酶活性的生态剂量 ED50 结果发现 ,土壤脲酶活性的 ED50 值最小 ,反映出脲酶对杀虫双反应最敏感 ,建议采用土壤脲酶活性作为土壤杀虫双污染程度的监测指标 ;此外获得了土壤中杀虫双污染浓度的 ED50 值 :土娄土和红壤分别为 1.30 1和0 .5 2 6 g/ kg。转化酶活性表现出在杀虫双低浓度时激活 ,在高浓度时抑制的变化规律。

The fluctuations of soil enzyme activity under different dimehypo concentrations were studied in simulated conditions.The results showed that dimehypo could remarkably inhibit the activity of soil urease,polyphenol oxidase and peroxidase in Lou soil and Red soil sampled in North and South China,respectively,enzyme activity has largely inhibited at low dimehypo concentration,less inhibited at high dimehypo concentration.ED50,the ecological dimehypo dose at 50% reduction of soil enzyme activity,was calculated to express the sensitivity of soil enzyme to dimehypo.ED 50 of dimehypo for urease in Lou soil and Red soil were 1.301 and 0.526 g/kg respectively.It can be known according to ED 50 that soil urease is the most sensitive to dimehypo among all tested soil enzyme.It is very interesting that soil invertase is activated and its activity is enhanced at low concentration of dimehypo,and then is inhibited at high concentrations.