甲磺隆结合残留对土壤酶活性的影响

为了研究甲磺隆结合残留对土壤酶活性的影响,将黄粉土(水稻土)经甲磺隆结合残留处理98天,检测土壤脲酶、酸性磷酸酶、过氧化氢酶和蔗糖酶活性.结果表明,甲磺隆结合残留对土壤酶活性的影响不仅与甲磺隆结合残留处理浓度和培养时间有关,同时还与土壤酶种类有关.培养前期(第14天前),甲磺隆结合残留对土壤酸性磷酸酶和过氧化氢酶具有抑制作用,而对土壤脲酶和蔗糖酶的影响则表现为低浓度时激活,高浓度时抑制;培养后期(第14天后),甲磺隆结合残留对土壤脲酶、酸性磷酸酶和过氧化氢酶具有激活作用,在一定浓度范围内(0.050~0.281mg·kg-1)对土壤蔗糖酶也具有一定激活作用;就土壤酶而言,在污染早期,土壤过氧化氢酶对甲磺隆结合残留较敏感,可以作为表征甲磺隆结合残留土壤污染的生物活性指标.

Effects of Bound Residues of Metsulfuron-Methyl on Soil Enzymatic Activities

In order to investigate effects of bound residues of metsulfuron-methyl(BR) on the activities of soil enzymes, the activities of urease, acid phosphatase, catalase, and sucrase were determined in Huangfentu(rice soil)spiked with bound residues of metsulfuron-methyl for 98 days. Effects of BR in soil on soil enzymatic activities depended not only on the level of BR treatments and the time when BR stayed in soil, but also on the soil enzyme types. In the earlier period of incubation(before 14 days), BR could inhibit the activities of acid phosphatase and catalase, however could activate and inhibit the activities of urease and sucrase at the low level and at the high level, respectively. In the later period of incubation(after 14 days), BR could activate the activities of urease, acid phosphatase, and catalase at all the levels. BR could also activate the sucrase activity at the level of 0.050 to 0.281mg·kg-1. In terms of soil enzymes, catalase was more sensitive to bound residues of metsulfuron-methyl than other soil enzymes, and could be taken as the indicator to indicate the microbial activities of soils contaminated by BR.