Duplicate 5 g samples of each duplicate treatment (500 g of unamended or amended soil) were taken at each sampling time and shaken at 20 °C for 2 h with 10 mL of methanol:water (1:1) in glass tubes. The samples were then sonicated for 1 h and centrifuged at 5045 g for 15 min, and the pesticide extracts were filtered in a Minisart NY 25 filter (Sartorius Stedim Biotech, Germany) to remove particles N0.45 μm. For the determination of the herbicide and its possible metabolites, a volume of the extract was transferred to a glass vial for analysis. The recoveries of the extraction method were determined by spiking three unamended and amended soil samples with analytical grade pesticide to a final concentration of 2 mg kg−1 and performing the extraction procedure as described above. The mean recovery values were 76% for S,
74% for S + C, and 74% for S + SS.