Adsorption and leaching studies of molinate, carbofuran and propiconazole in Muda agricultural soils

A.M. Khairatul, C.K. Ngan and B.S. Ismail

Abstract

The adsorption and leaching studies of molinate, carbofuran and propiconazole on silty clay soil were conducted under laboratory conditions. Propiconazole (Kf value = 52.94 litres/kg) was the most strongly adsorbed pesticide by silty clay soil as compared to molinate (Kf value = 10.22 litres/kg) and carbofuran (Kf value = 6.59 litres/kg). The 1/n values of molinate (0.99) showed that the ability of molinate to be adsorbed into silty clay soil decreased when the concentration of molinate in solution increased. Carbofuran and propiconazole tend to be adsorbed more into silty clay soil when their concentrations in solution increased. Soil columns with a length of 60 cm were erected and the pesticides were leached with distilled water for 7 days (molinate = 1.03 kg/ha, carbofuran = 0.42 kg/ha and propiconazole = 0.042 kg/ha). No residues of molinate (<1.0 ng ml), carbofuran (<3.2 ng/ml) and propiconazole (<0.1 ng/ml) were detected in the leachate.

Full Text (358 KB)