INVESTIGADORES
MERINI Luciano Jose
artículos
Título:
Degradation of 2,4-DB in Argentinean agricultural soils with high humic matter content
Autor/es:
CUADRADO, V; MERINI, LJ; FLOCCO, CG; GIULIETTI, AM
Revista:
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
Editorial:
Springer
Referencias:
Año: 2007 vol. 77 p. 1371 - 1378
ISSN:
0175-7598
Resumen:
The dissipation of 4-(2,4-dichlorophenoxy) butyric
acid (2,4-DB) in high-humic-matter-containing soils from
agricultural fields of the Argentinean Humid Pampa region
was studied, employing soil microcosms under different
experimental conditions. The added herbicide was dissipated
almost completely by soils with and without history of
herbicide use by day 28. At 500 ppm, both soils showed the
same degradation rates; but at 5-ppm concentration, the
chronically exposed soil demonstrated a faster degradation
of the herbicide. 2,4-DB addition produced increases in
herbicide-degrading bacteria of three and 1.5 orders of
magnitude in soils with and without history of herbicide use,
respectively, in microcosms with 5 ppm. At 500-ppm
concentration, the increase in 2,4-DB degraders was five
orders of magnitude after 14 days, independent of the
history of herbicide use. No differences were observed in
either 2,4-DB degradation rates or in degrader bacteria
numbers in the presence and absence of alfalfa plants, in
spite of some differential characteristics in patterns of 2,
4-DB metabolite accumulation. The main factor affecting
2,4-DB degradation rate would be the history of herbicide
use, as a consequence of the adaptation of the indigenous
microflora to the presence of herbicides in the field.