Mobility of pesticides in soils. Influence of soil properties and pesticide structure

Abstract

A comparative study was made of the mobility of five pesticides with different structures in 13 natural soils with different chemical and physical properties. Pesticide mobility was determined using soil thin layer chromatography and l4C‐labelled compounds. According to the Rf values, pesticide mobility varied in the following order: acephate > fluometuron > atrazine > ethofumesate > glyphosate, acephate being highly mobile, while atrazine, fluometuron and ethofumesate were mobile, and glyphosate was immobile. The results provided by linear regression analysis show highly significant correlation coefficients (p < 0.001) between the Rf values of atrazine, ethofumesate and fluometuron and soil organic matter content. There was also a significant correlation (p < 0.01) of the Rf of glyphosate with the soil silt + clay content. Despite this, it was found that dissolved organic matter influences the mobility of the five pesticides and that the soil phosphate content affects the mobility of glyphosate.