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分布于松嫩平原西部大型灌区的内陆盐碱化沼泽在农田退水的水资源利用与农业非点源污染控制中起着非常重要的作用,但是,农田退水中残留的除草剂对盐碱化沼泽的影响尚不明晰。2014年7~9月,在松嫩平原西部盐碱化沼泽集中分布区,通过大田模拟实验,研究芦苇(Phragmites australis)对稻田退水中除草剂苄嘧磺隆的生态响应特征,比较不同苄嘧磺隆浓度下湿地土壤酶活性的变化。结果表明,在不同苄嘧磺隆添加量(0.009 9 g/m2、0.019 9 g/m2和0.039 8 g/m2)处理下,7~9月芦苇株高和茎粗都未受显著抑制,且与对照处理相比,株高分别增高15.37%、13.13%和11.48%,茎粗分别增加7.7%、0.7%和11.2%;芦苇干质量波动变化;但芦苇叶片的可溶性糖含量显著降低;光合特性方面,随着苄嘧磺隆含量的增加,芦苇叶片的净光合速率、气孔导度和蒸腾速率都未显著减小,仅胞间CO2浓度在高添加量苄嘧磺隆处理下显著高于对照处理;而苄嘧磺隆对土壤各种酶活性的影响存在差异,未对土壤过氧化氢酶和蔗糖酶活性产生显著抑制,且在高添加量苄嘧磺隆处理下还激活了土壤碱性磷酸酶活性。在淹水深度为15 cm的实验条件下,在苄嘧磺隆添加量≤0.039 8 g/m2的处理下,盐碱沼泽中的芦苇和土壤酶活性未表现出显著的毒理风险。
Inland salinization swamps distributed in the large-scale irrigation areas in the west of the Songnen Plain play a very important role in the utilization of water resources for farmland reclamation and non-point source pollution control in agriculture. However, The impact of the swamp is not clear. From July to September 2014, the ecological response characteristics of Phragmites australis, a herbicide in the paddy field, were studied in the salinized swamp concentrated area in western Songnen Plain by field simulation experiments. Changes of soil enzyme activities in wetlands under the soil profile of. The results showed that under different bensulfuron-methyl treatments (0.009 9 g / m2, 0.019 9 g / m2 and 0.039 8 g / m2), the height and stem diameter of P. reedii from July to September were not significantly inhibited, Compared with the control, the plant height increased by 15.37%, 13.13% and 11.48%, and the stem diameter increased by 7.7%, 0.7% and 11.2%, respectively. The dry weight of the reed changed obviously, but the soluble sugar content of the reed leaves decreased significantly. With the increase of bensulfuron-methyl content, the net photosynthetic rate, stomatal conductance and transpiration rate of reed leaves did not decrease significantly. Only the intercellular CO2 concentration was significantly higher than that of the control under the high addition of bensulfuron-methyl While the bensulfuron-methyl had different effects on the activities of various enzymes in the soil, but did not significantly inhibit the activity of catalase and sucrase in the soil, and also activated the alkalinity of the soil under the high addition of bensulfuron-methyl Phosphatase activity. Under the condition of flooding depth of 15 cm, the enzyme activity of reed and soil in salinized marsh showed no significant toxicological risk under the condition of bensulfuron-methyl addition ≤0.039 8 g / m2.