Chlorsulfuron除草劑在環境中的分解與殘留

Degradation and Remaining of Chlorsulfuron in Environment

賴郁仁(Yun-Zein Li) ； 王慶裕(Ching-Yuh Wang)

《中華民國雜草學會會刊》 24卷1期 (2003/06) Pp. 49-56

摘要

本文主要介紹硫醯尿素類除草劑chlorsulfuron在環境中的分解路徑及影響其分解速率的因子，其在水中之水解有兩大路徑，其一為sulfonylurea bridge 的斷裂，其二為demethylation路徑。當水溶液pH值低於6.2或高於10.2時，chlorsulfuron皆具有最高之水解速率。Chlorsulfuron在土壤表面之光解可能只發生在土表0.1~0.5mm的範圍內，在耕地土壤中的分解第一階段為快速分解期(0~60天)，此階段微生物分解與化學水解同時進行，第二階段為緩慢分解期(60~180天)，此時期chlorsulfuron被土壤大量吸附，使得微生物無法利用分解，只能進行化學水解。Chlorsulfuron在環境中的殘留包括本身及其代謝物會先與土壤有機質結合，之後再釋出於環境或進入植體中。

關鍵字

硫醯尿素類除草劑 ； 環境殘留 ； 化學水解 ； 微生物分解

並列摘要

Both the degradation pathway and the related factors influencing degradation of chlorsulfuron, one of sulphonylurea herbicides, were reviewed. Chlorsulfuron in aqueous solution may degrade through the breakage of sulfonylurea bridge and the demethylation of herbicide molecule. And the maximum rate of chlorsulfuron hydrolysis was observed at the pH either below 6.2 or higher than 10.2. The photolysis of chlorsulfuron on soil surface only occurs within 0.1 to 0.5 mm in depth. It has been reported that the maximum degradation of chlorsulfuron in tillage field occurred from 0 to 60 days after application (DAT), through microbial degradation and chemical hydrolysis; and then followed by the slower degradation from 60 to 180 DAT, which was through hydrolysis only, without microbial activity, due to the binding of chlorsulfuron to soil particle. Chlorsulfuron and its metabolites in soil may bind to some organic substances and release subsequently.

並列關鍵字

chlorsulfuron ； environmental residue ； chemical hydrolysis ； microbial degradation