Mobility studies of atrazine in the soil-plant system in two cameroonian vegetables Amaranthus hybridus and Corchorus olitorius

Abstract

Abstract The objective of this work is to assess the level of contamination of the soil-plant system by atrazine which is a pesticide classified as dangerous in the European Union, but approved in Cameroon. To achieve this aim, two plant species (Amaranthus hybridus and Corchorus olitorius) were grown in pots according to the method developed by farmers in the field. In other words, each pot was treated with three dosages of atrazine (22.5 ​g/L; 45 ​g/L and 90 ​g/L). Later, the crops were harvested at four stages of growth and the atrazine was analysed in the soil and in the plants by HPLC-UV. The results show that the concentration of atrazine decreased from 4.66 ​mg/L in the soil after 15 days of growth of the plant to 1.96 ​mg/L after 2 months of growth. This evolution is also observed within the two plant species with a significant treatment effect. Thus, the highest concentrations of atrazine were found in the roots of plants harvested from soils treated with 90 ​g/L of atrazine. Besides, the maximum average content of atrazine of 0.74 ​mg/kg of dry matter was found in the edible part of the two plant species at their stage of maturity. Finally, atrazine is persistent in the agricultural soil after two months regardless of the dose. Given the amount of atrazine translocated into the edible leaves, this herbicide should not be used for the cultivation of the two vegetables studied, contrary to what is practiced in the field in Ngaoundere (Cameroon).