土壤酶活性对2,4-D丁酯的动态响应

通过盆栽试验,研究了种植条件下2,4-D对土壤脲酶、碱性磷酸酶和蛋白酶活性的动态影响。结果表明,与对照相比,低浓度2,4-D对脲酶活性有较强的激活作用,且随着处理时间的延长以及2,4-D浓度的增大酶活性增强,最高激活率达151%;高浓度2,4-D对脲酶活性表现为先抑制后激活。不同浓度2,4-D对碱性磷酸酶活性呈先激活后抑制又激活的趋势。当2,4-D浓度为0.25mL/L时,对蛋白酶活性具有激活作用;当2,4-D浓度增大时,蛋白酶活性表现为先抑制后激活。可见,2,4-D对土壤酶活性的影响,不仅与2,4-D的浓度和处理时间有关,还与土壤酶的种类有关,反映出土壤酶活性在一定程度上可作为除草剂污染土壤环境质量变异的有效指标。

Dynamic Response of 2,4-D Butyl Ester to Soil Enzyme Activities

Dynamic effects of 2,4-D to soil urease, alkaline phosphatase and protease activities were studied by pot experiments under the conditions of cultivation. The results showed that, compared with the control, low concentration 2,4-D had strong activation to the urease activity, and processing with the time and increased 2,4-D concentration, the urease activity increased and the maximum activation rate reaching 151%. High concentration 2,4-D inhibited first and activated later to the urease activity and various 2,4-D concentrations first activated, then inhibited, and activated to the alkaline phosphatase activity. When 2,4-D concentration was 0.25 ml/L, the protease activity was activated, while its change trend showed first inhibition and activation later with increasing of 2,4-D concentration. So, the effect of 2,4-D to soil enzyme activities was related not only with 2,4-D concentration and time processing, but also with the type of soil enzymes. It showed that the soil enzyme activity could be used as an effective indicator of herbicides pollution variability to soil quality to certain extent.