Agronomie 24 (2004) 177-183
DOI: 10.1051/agro:2004019

Fate of isoproturon in two Moroccan soils

Kaouakeb Elkhattabi^a, Ahmed Bouhaouss^a, Corinne Perrin-Ganier^b and Michel Schiavon<sup>b

a</sup>  Laboratoire de Chimie Physique Générale, Département de Chimie, Faculté Des Sciences, Rabat, Morocco
^b  Laboratoire Sols et Environnement, École Nationale Supérieure d'Agronomie et des Industries Alimentaires, BP 172, 54505 Vandoeuvre-lès-Nancy, France

(Received 3 February 2003; accepted 3 April 2004)

Abstract - The study of the adsorption, desorption, degradation and stabilization of ¹⁴C-isoproturon in two clayey Moroccan soils of the Gharb area were investigated under laboratory conditions. Adsorption follows a non-linear isotherm. A strong affinity of clays to isoproturon was observed. Dehs soil affinity to isoproturon is stronger than that of the Tirs soil, with: K_OC = 112.1 and 84.5, respectively. Non-extractible residues reached 36.3%, 35.4% and 32.0% of initial applied amounts in 60 days, respectively, for the Tirs soil, the Tirs soil treated with nitrogen and the Dehs soil. The pseudo half-life of isoproturon ranged from 31 to 50 days. Degradation products of isoproturon were N'-(4-isopropylphenyl)- N,N-dimethylurea and N'-[4-(2-hydroxyisopropylphenyl)]-N-methylurea, and other non-identified products.

Key words: isoproturon / retention / degradation / stabilization / Moroccan soils

Corresponding author: Ahmed Bouhaouss bouhaous@fsr.ac.ma

© INRA, EDP Sciences 2004