| Issue |
Agron. Sustain. Dev.
Volume 28, Number 2, April-June 2008
|
|
|---|---|---|
| Page(s) | 231 - 238 | |
| DOI | https://doi.org/10.1051/agro:2008009 | |
| Published online | 22 March 2008 | |
DOI: 10.1051/agro:2008009
Sorption and desorption of organophosphate pesticides, parathion and cadusafos, on tropical agricultural soils
Angeluz Olvera-Velona1, Pierre Benoit2, Enrique Barriuso2 and Laura Ortiz-Hernandez11 Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, 62210 Cuernavaca, Morelos, Mexico
2 INRA-AgroParisTech., UMR Environnement et Grandes Cultures, 78850 Thiverval-Grignon, France
Accepted 16 Junuary 2008; published online 22 March 2008
Abstract - Ecotoxicological impacts of organic pesticides on soil
and aquatic ecosystems depend primarily on their behavior in soils. Actual
pesticide knowledge is mostly restricted to soils from temperate climates,
whereas knowledge of pesticide behavior in tropical soils is scarce. Here,
the sorption behavior of two organophosphorous insecticides, parathion and
cadusafos, was studied in three agricultural soil samples from central
Mexico, Vertisols and Andosols. Using 14C-labeled substances, we
assessed sorption and desorption properties in classical batch equilibrium
and static soil incubation experiments. Our results show that cadusafos was
less sorbed by the various soils (
values 7.6-12.7 L kg-1)
compared with parathion ( values 38.6-74.9 L kg-1), despite
similar log
values. Cadusafos exhibited a greater reversibility of
sorption than parathion in both soil types. Time-dependent sorption was
quantitatively significant, leading to a rapid decrease in the concentration
of available insecticide. This finding is partly due to the formation of
non-extractable, bound residues. The decrease in the available concentration
of both insecticides was greater in the Andosol compared with the Vertisols.
Soil organic matter clearly influenced the sorption behavior and
availability of parathion. On the other hand, the sorption of cadusafos was
more influenced by other soil properties such as clay content and cation
exchange capacity. Calculation of residual insecticide levels in the soil
solution suggests that both insecticides may have persistent toxic effects
in the studied soils.
Key words: desorption / organophosphorous / insecticides / adsorption
Corresponding author: benoit@grignon.inra.fr
© INRA, EDP Sciences 2008