CONTRATADOS
GIULIETTI Ana Maria
artículos
Título:
Degradation of 2,4-D in the rhizosphere: optimization of herbicide analyses in complex soil samples and biodegradation assessment in microcosm
Autor/es:
MERINI, L.J.; CUADRADO, V.; FLOCCO, C.G; GIULIETTI A.M.
Revista:
Chemosphere
Editorial:
Elsevier
Referencias:
Año: 2007 vol. 68 p. 259 - 259
ISSN:
0045-6535
Resumen:
Abstract Phenoxy herbicides like 2,4-dichlorophenoxyacetic acid (2,4-D) are widely used in agricultural practices. Although its half life in soil is 7–14 d, the herbicide itself and its first metabolite 2,4-dichlorophenol (2,4-DCP) could remain in the soil for longer periods, as a consequence of its intensive use. Microcosms assays were conducted to study the influence of indigenous microflora and plants (alfalfa) on the dissipation of 2,4-D from soils of the Humid Pampa region, Argentina, with previous history of phenoxy herbicides application. Results showed that 2,4-D was rapidly degraded, and the permanence of 2,4-DCP in soil depended on the presence of plants and soil microorganisms. Regarding soil microbial community, the presence of 2,4-D degrading bacteria was detected even in basal conditions in this soil, possibly due to the adaptation of the microflora to the herbicide. There was an increment of two orders of magnitude in herbicide degraders after 15 d from 2,4-D addition, both in planted and unplanted microcosms. Total heterotrophic bacteria numbers were about 1 · 108· 108 CFU g1 dry soil and no significant differences were found between different treatments. Overall, the information provided by this work indicates that the soil under study has an important intrinsic degradation capacity, given by a microbial community adapted to the presence of phenoxy herbicides. indicates that the soil under study has an important intrinsic degradation capacity, given by a microbial community adapted to the presence of phenoxy herbicides. indicates that the soil under study has an important intrinsic degradation capacity, given by a microbial community adapted to the presence of phenoxy herbicides. 1 dry soil and no significant differences were found between different treatments. Overall, the information provided by this work indicates that the soil under study has an important intrinsic degradation capacity, given by a microbial community adapted to the presence of phenoxy herbicides. 2007 Elsevier Ltd. All rights reserved.2007 Elsevier Ltd. All rights reserved.