2024-03-28T14:55:00Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1335362018-09-10T11:22:45Zcom_10261_15com_10261_6col_10261_268
2016-06-16T06:04:15Z
urn:hdl:10261/133536
Effect of synthetic clay and biochar addition on dissipation and enantioselectivity of tebuconazole and metalaxyl in an agricultural soil: Laboratory and field experiments
Gámiz, B.
López-Cabeza, R.
Facenda, G.
Velarde Muñoz, Pilar
Hermosín, M.C.
Cox, L.
Celis, R.
Ministerio de Economía y Competitividad (España)
Junta de Andalucía
European Commission
Chiral pesticides
Degradation
Leaching
Organic amendments
Hydrotalcite
10 páginas.-- 4 figuras.-- 3 tablas.-- referencias.-- Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.agee.2016.05.017
Laboratory and field experiments were conducted to assess how the addition of oleate-modified hydrotalcite (clay) and biochar (BC) to an agricultural soil affected the sorption, leaching, persistence, and enantiomeric composition of soil residues of two chiral fungicides, tebuconazole and metalaxyl. Laboratory experiments showed that the sorption of both fungicides ranked as follows: unamended soil < BC-amended soil < clay-amended soil. The addition of clay at a rate of 1% increased metalaxyl soil sorption coefficient (Kd) from 0.34 to 3.14 L kg−1 and that of tebuconazole from 2.4 to 47.4 L kg−1. In our experimental set-up, field plots were either unamended or amended with clay (2 t ha−1) or BC (4 t ha−1), and subsequently treated with a mixture of tebuconazole and metalaxyl at 3 and 6 kg ha−1, respectively. The leaching, persistence, and enantiomer composition of fungicides residues were monitored by sampling at different soil depths (0–5, 5–10, 10–20 cm) for 98 days. No significant changes in the scarce mobility and long persistence of tebuconazole upon amending the soil with clay or BC were observed. In contrast, sorption to clay and BC particles reduced the leaching and degradation of metalaxyl and the clay increased its persistence in the topsoil compared to the unamended soil. The enantioselective analysis of tebuconazole and metalaxyl soil residues indicated that tebuconazole remained mostly racemic along the experiment, whereas for metalaxyl the concentration of S-enantiomer was greater than the concentration of R-enantiomer, more so at longer experimental times and deeper horizons. Nevertheless, for the top 0–5 cm soil layer metalaxyl remained more racemic in clay- and BC-amended soil than in unamended soil. Our results show that addition of amendments with high sorptive capacities can be beneficial in reducing leaching and degradation losses of chiral pesticide enantiomers from the topsoil, and that sorption by the amendments can influence the final enantiomeric composition of pesticide residues.
2016-06-16T06:04:15Z
2016-06-16T06:04:15Z
2016-08-16
artículo
Agriculture Ecosystems and Environment 230: 32–41 (2016)
0167-8809
http://hdl.handle.net/10261/133536
10.1016/j.agee.2016.05.017
http://dx.doi.org/10.13039/501100003329
http://dx.doi.org/10.13039/501100000780
http://dx.doi.org/10.13039/501100011011
eng
Preprint
http://dx.doi.org/10.1016/j.agee.2016.05.017 0
Sí
info:eu-repo/grantAgreement/MINECO/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/AGL2013-48446-C3-1-R
info:eu-repo/grantAgreement/MINECO/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/AGL2014-51897-R
openAccess
Elsevier