Zhu Ye, Li Qing X
Department of Molecular Biosciences and Bioengineering, University of Hawaii, Honolulu 96822, USA.
Chemosphere. 2002 Nov;49(6):669-74. doi: 10.1016/s0045-6535(02)00392-2.
Bromacil and hexazinone have been heavily used to control weeds in the pineapple fields in central Oahu, Hawaii, USA, since 1970s and 1980s, respectively. The last application prior to this study was at a rate of 0.6 kg active ingredient (a.i.) ha(-1) for hexazinone and 1.8 or 3.4 kg (a.i.) ha(-1) for bromacil in the six study fields during June-October 1998. Soils were collected from 0 to 1860 cm below the surface in January-May 1999 to survey the residue profiles of the two herbicides. Stratoprobe sampling showed to be an efficient and convenient method for deep soil cores. Bromacil was detected in all the soil samples above 60 cm (105-1338 ng g(-1) dry weight) and in 74% of the samples above 400 cm (26-473 ng g(-1)). Trace amounts of bromacil (90-113 ng g(-1)) were detected in some of the samples collected from as deep as 1540 cm. Hexazinone was detected in three of the six fields at 0-60 cm only (86-107 ng g(-1) dry weight). The more frequent detection of bromacil at higher concentrations than hexazinone is related to the prolonged higher application rates of bromacil in the fields and its higher persistence and mobility in soil.
自20世纪70年代和80年代以来，除草定和嗪草酮分别被大量用于美国夏威夷瓦胡岛中部菠萝田的杂草防治。在本研究之前的最后一次施用是在1998年6月至10月期间，六个研究田块中嗪草酮的施用量为0.6千克活性成分（a.i.）/公顷，除草定的施用量为1.8或3.4千克（a.i.）/公顷。1999年1月至5月从地表以下0至1860厘米处采集土壤，以调查这两种除草剂的残留情况。分层探针取样显示是一种获取深层土壤岩心的高效便捷方法。在60厘米以上的所有土壤样本中均检测到除草定（干重105 - 1338纳克/克），在400厘米以上的样本中有74%检测到除草定（26 - 473纳克/克）。在一些从深达1540厘米处采集的样本中检测到痕量的除草定（90 - 113纳克/克）。嗪草酮仅在六个田块中的三个田块0 - 60厘米处被检测到（干重86 - 107纳克/克）。除草定比嗪草酮更频繁地被检测到且浓度更高，这与田间除草定施用率长期较高及其在土壤中更高的持久性和迁移性有关。
