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The Gharb region in Morocco is an important agricultural zone where soils receive pesticide treatments and organic amendments to increase yields. The groundwater aquifer in the Gharb region is relatively shallow and thus vulnerable. The objective of this work was to study the influence of organic amendments on diuron, cyhalofop-butyl and procymidone leaching through undisturbed soil columns. Two soils were sampled from the Gharb region, a Dehs (sandy soil) and a R’mel (loamy clay soil). Following elution (124.5 mm), the amount of pesticide residues in the leachates of the sandy soil (0.06–0.21 %) was lower than in those of the loamy clay soil (0.20–0.36 %), which was probably due to preferential flow through the loamy clay soil. The amount of procymidone leached through the amended soil columns was greater than the control for the sandy soil only. The organic amendments did not significantly influence diuron and cyhalofop-butyl leaching in either of the soils. The application of organic amendments affected the amounts of dissolved organic matter (DOM) eluted and thus pesticide leaching as a function of soil-type. Nevertheless, in some case, the formation of pesticide-DOM complexes appeared to promote pesticide leaching, thus increasing groundwater contamination risks. [ABSTRACT FROM AUTHOR]

Eight pesticide residues in tomato samples collected in the area of Souss Massa Valley (Southern Morocco) were analyzed. The detected residue levels ranged from 0.001 to 0.400 mg kg for dicofol, from 0.003 to 0.170 mg kg for procymidone, from 0.001 to 0.250 mg kg for chlorothalonil, from 0.050 to 0.500 mg kg for bifenthrin, from 0.001 to 0.010 mg kg for λ-cyhalothrin, from 0.001 to 0.300 mg kg for cypermethrin, from 0.010 to 1 mg kg for deltamethrin and from 0.003 to 1.123 mg kg for endosulfan. European MRL for endosulfan in tomatoes set in 0.500 mg kg, was exceeded in 8 samples, and MRL for deltamethrin set in 0.300 mg kg for tomatoes was exceeded in 2 samples. [ABSTRACT FROM AUTHOR]