Chiang Mai Journal of Science

 The pesistence of carbofuran in saline soil and saline water was investigated. Soil used in this study was collected from the saline soil paddy field in Ban Phai District, Khon Laen Province. Saline water was taken from the water trapped above the soil in saline soil paddy field. The salinity was measured using electrical conductivity. There were 4 levels of saline soil samples i.e., no salinity, low salinity, medium salinity and high salinity with the electrical conductivity (EC) of 1, 2.6, 4.6 and 9.0 mmho/cm, respectively. The EC of saline water samples were 1.0, 3.0, 6.0 and 8.0 for none, low, medium and high salinity, respectively. Carbofurans was rapidly degraded in saline soil at all salinity levels. However, salinity did not affect carbofuran degradation in soil. The longer half-life values, 22-33 day, in non-autoclaved soil than in autoclaved soil, 9-18 days, suggesting a non-persistence and biologically degradation of carbofuran in saline soil. Salinity affected the persisitence of carbofuran in saline water. As the salinity in water increased the pH of water increased resulting to less persistence of carbofuran. This may due to a chemical hydrolysis since an increased of pH in the saline water resulting to a hydrolysis of carbofuran at high pH. The half-life values in saline water were found to be 17-29 days and 17-33 days in autoclaved and non-autocalved saline water, respectively, suggesting the degradation of carbofuran in water was not a biologically degradation dependent.