稻菜轮作制下汞胁迫的土壤微生物学和酶学效应

Microbial and Enzymatic Effects of Hg Stress in Soil of Rice-Vegetable Cabbage Rotation System

通过盆栽试验研究了稻菜轮作下不同浓度汞污染对土壤微生物和酶活性的影响,从而为稻菜轮作体制下土壤重金属污染防治、诊断提供科学理论依据。结果表明:青菜收获后,不同浓度汞处理后土壤各微生物学指标和酶学指标均表现为在较低浓度汞处理(<2 mg/kg)时有促进作用,在较高浓度汞处理(≥2 mg/kg)时表现出抑制作用。综合比较,土壤代谢商是对汞处理比较敏感的微生物学指标。青紫泥不同浓度汞处理的土壤酶活性大于小粉土。脲酶是对土壤汞胁迫比较敏感的生化监测指标,且汞对小粉土脲酶和脱氢酶活性的生态毒性强于青紫泥。

Both laboratory and greenhouse pot experiments were conducted to investigate mercury ecological dose responses of soil microbial and enzymatic activities in rice-vegetable cabbage rotation system at different Hg^2＋ loadings. The results showed that after harvesting Chinese cabbage plant, all measured microbial and enzymatic indices increased with the increasing level of Hg treatments at low concentrations （〈2 mg/kg） and decreased with the increasing level of Hg treatments at high concentrations （≥2 mg/kg）. Soil metabolic quotient is more sensitive to Hg contamination than the other microbial indices. Enzymatic activity of the PCS soil was higher than the SLS soil. Urease is more sensitive biochemical monitoring indexes to soil mercury stress. The analysis of ED50 indicated that ecological toxicity of urease and acid phosphatase of the SLS soil was stronger than the PCS soil.