PESTICIDE OCCURRENCE AND DISTRIBUTION IN CULTIVATED SOILS OF THE ARID REGION OF EL-HEJERA, OUARGLA PROVINCE AND CORRELATION WITH SOIL PROPERTIES

Abstract

This study deals with the assessment of the most used pesticides by farmers in the Saharan region of Ouargla. Based on collected survey data, sampling of the cultivated soils, physicochemical analysis, solid/liquid extraction and identification by thin layer chromatography and high performance liquid chromatography, the following results were obtained: pesticides used in 2015 are not existing in the extracts, like the case of vapcomic (abamectin 1.8% EC) and Metronate (methomyle 25%), this could be explained by the retention which is the overall result of a set of elementary processes, involving interactions with organic constituents and soil minerals. Also, pesticide residues were found outside their points of application, such as Pulsar and Score 250EC, these phenomena can be explained by the local pedo-climatic conditions and to difference in solubility and chemical nature.