The effect of rhizosphere soil addition on ametryn degradation rate was evaluated. The 14CO2 release rate from sterile and non-sterile samples of a sandy soil was compared with the same soil amended with 10% rhizosphere soil from a sugar-cane plantation, treated or not with ametryn. Sterilized soils showed very low 14CO2 release as compared with non-sterilized soil. When mineralization of non-amended soil was compared with rhizosphere soil amended from treated and non-treated fields, 3.5 and 1.7 fold increases of mineralization, respectively, were observed in amended soil. Extract TLC showed more degradation on amended samples than on non-amended samples. These results suggest that ametryn is degraded mainly through microbial action and that amendment with soil microbial population from ametryn pre-treated soil increases this herbicide's degradation rate.
mineralization; herbicide; phytoremediation; bioremediation