Pesticide residues in the surface runoff
The purpose of this study is to investigate the amount of pesticide washed out under the influence of different rainfall intensities and different time intervals between the pesticide application and the first rainfalL Three different rainfall intensities were simulated on an experimental plot an...
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| 主要作者: | |
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| 格式: | Thesis |
| 語言: | English |
| 出版: |
2005
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| 主題: | |
| 在線閱讀: | http://ir.unimas.my/id/eprint/14835/3/Tay%20Teck%20Pinfull.pdf |
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| 總結: | The purpose of this study is to investigate the amount of pesticide washed out under the
influence of different rainfall intensities and different time intervals between the pesticide
application and the first rainfalL Three different rainfall intensities were simulated on an
experimental plot and administered in different time intervals after pesticide application.
Both the surface runoffs and the soil samples were taken for pesticide analysis in the
laboratory. The extracted pesticide from both the water and the soil samples were later
determined by gas chromatography with flame phosphorus detector. Generally, the
results show a similar trend of pesticide wash out in the surface runoff. There was no
significant different in the wash out of pesticide in the surface runoff among the three
rainfall intensities studied. All the three rainfall intensities had shown that the l-h and 2h
time intervals after the pesticide application, were more susceptible to being washed out
in the runoff. It was observed that there was a significant different (p<0.05) in the
pesticide amount between the short hour time intervals and the long hour time intervals
runoff. Parallel to most studies, most of the pesticide was found to have accumulated in
the soil after high frequencies of pesticide applications. The soil in the light rainfall
intensity had adsorbed the most amount of pesticide. Comparatively, the soil under the
heavy rainfall intensity had the least amount of pesticide adsorbed among the three
rainfall intensities. Nonetheless, the amount of pesticide found in the soil of all the three
rainfall intensities was ranging from 1.06 mg/kg to 9.44 mg/kg. The observation had
concluded that in the long hour time intervals degradation processes and the
crystallization of the pesticide on the soil particles had accounted for the lower amount of
pesticide washed out in the surface runoff. Thus, for the amount of pesticide washed out in the surface runoff, the time interval between the pesticide application and the first rainfall was the major factor. |
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