Wang Jinhua, Lu Yitong, Ding Hui, Shen Guoqing
Department of Environment and Resource, College of Agriculture and Biology, Shanghai Jiaotong University, Shanghai, 201101, China.
Environ Geochem Health. 2007 Oct;29(5):395-403. doi: 10.1007/s10653-007-9084-2. Epub 2007 Feb 27.
The ecological toxicity of cadmium (Cd, 10 mg kg(-1 )of dry weight soil) and butachlor (10, 50 and100 mg kg(-1 )of dry weight soil) in both their single and combined effects on soil urease and phosphatase was studied after 1, 3, 7, 14, 21 and 28 days exposure under controlled conditions in paddy and phaeozem soils. The results showed that Cd reduced the activities of urease and phosphatase at early incubation time (1-7 days), while the reduction almost disappeared at the end of the incubation. The effect of Cd on phosphatase was more pronounced than that on urease. The activities of urease and phosphatase were reduced by butachlor, while urease activity was significantly (P < 0.05 or P < 0.01) improved when the concentrations of butachlor were 10 and 50 mg kg(-1) at the end of the incubation. When Cd (10 mg kg(-1)) was combined with butachlor (50 and 100 mg kg(-1)), the activities of urease and phosphatase became lower than without combination at early incubation time, which indicated that the toxicity of Cd significantly increased (P < 0.05 or P < 0.01). However, when Cd (10 mg kg(-1)) was combined with butachlor (10 mg kg(-1)), the activities of urease and phosphatase became higher than those without combination at the end of the incubation, which indicated that the toxicity of Cd decreased. It was indicated that the combined effects depended largely on the incubation time and the concentration ratio of Cd and butachlor. In addition, it was showed that the combined effects of butachlor and Cd appeared different in paddy from phaeozem, which may be related to the different properties of these soils.
在可控条件下，研究了镉（Cd，干重土壤中含量为10毫克/千克）和丁草胺（干重土壤中含量分别为10、50和100毫克/千克）对水稻土和黑土中土壤脲酶和磷酸酶的单一及复合生态毒性效应，暴露时间为1、3、7、14、21和28天。结果表明，Cd在培养初期（1 - 7天）降低了脲酶和磷酸酶的活性，但在培养末期这种降低几乎消失。Cd对磷酸酶的影响比对脲酶更显著。丁草胺降低了脲酶和磷酸酶的活性，但在培养末期，当丁草胺浓度为10和50毫克/千克时，脲酶活性显著提高（P < 0.05或P < 0.01）。当Cd（10毫克/千克）与丁草胺（50和100毫克/千克）复合时，在培养初期脲酶和磷酸酶的活性低于未复合时，这表明Cd的毒性显著增加（P < 0.05或P < 0.01）。然而，当Cd（10毫克/千克）与丁草胺（10毫克/千克）复合时，在培养末期脲酶和磷酸酶的活性高于未复合时，这表明Cd的毒性降低。结果表明，复合效应在很大程度上取决于培养时间以及Cd和丁草胺的浓度比。此外，还表明丁草胺和Cd的复合效应在水稻土和黑土中表现不同，这可能与这些土壤的不同性质有关。
