柴油和镉污染对土壤酶活性和微生物数量的影响

利用盆栽实验, 研究了土壤柴油污染、镉污染和柴油+镉复合污染对土壤酶活性和微生物数量的影响. 实验土壤为上海郊区无污染水稻土, 通过不同的处理, 共设计了对照(CK)、低量柴油(CYL)、高量柴油(CYH)、低量镉(CdL)、高量镉(CdH)、 高量柴油+高量镉(CYH+CdH)和高量柴油+高量镉+苗(CYH+CdH+P) 7 个处理组. 结果表明: CYH 和 CYH+CdH 处理增加了土壤脲酶(urease, UR)的活性, 最高可达 CK 组的 5.25 和 2.63 倍, 且土壤微生物数量也有相应增加; CYH、CYL 和 CYH+CdH 处理对脱氢酶(dehydrogenase, DE)活性有显著抑制作用; 镉的单污染对脱氢酶活性的影响较小, CdL 处理甚至有激活效应.

Effects of diesel fuel and Cd pollution on enzyme activity and microbial biomass in the soil

A pot experiment was conducted to study the effects of pollutants of diesel fuel and Cd alone or in combination on the activities of urease (UR) and dehydrogenase (DE) and microbial biomass in non-polluted paddy soil collected from an urban setting in Shanghai. The experiment included seven treatments: control (CK), low content of diesel fuel (CYL), high content of diesel fuel (CYH), low content of Cd (CdL), high content of Cd (CdH), combination of high content of diesel fuel and Cd (CYH+CdH), and combination of high content of diesel fuel, Cd and crop seedlings (CYH+CdH+P). The activity of UR was significantly raised when the soil was polluted with CYH and Cd for the treatments of CYH and CYH + CdH. The maximum UR for the two treatments was 5.25 and 2.63 times that of CK, respectively. The microbial biomass for the treatments was also correspondingly raised to some extent. Conversely, the activity of DE in the soil for the CYL, CYH and CYH + CdH treatments was significantly inhibited. The influence of Cd on DE activity in the soil was relatively mild. DE was activated even when the soil was polluted with CdL.