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| Titel |
Degradation pathway and field-scale DT50 determination of Boscalid in a sandy Soil |
| VerfasserIn |
Anneli S. Karlsson, Lutz Weihermüller, Wolfgang Tappe, Santanu Mukherjee, Sandra Spielvogel |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250133496
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| Publikation (Nr.) |
 EGU/EGU2016-14111.pdf |
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| Zusammenfassung |
| The research on environmental fate of pesticides has received increasing attention within the
last decades and the persistence of several compounds in soil matrices is well documented.
However, the fate of the new fungicide Boscalid (introduced in 2003) is not yet completely
investigated.
The aim of this study was to analyze the environmental fate of Boscalid in a sandy soil.
Three years after the second application on a cropland site in Kaldenkirchen, Germany, 65
undisturbed soil samples from the plough layer were derived.
Boscalid residues were extracted using Accelerated Solvent Extraction (ASE) and
measured with UPLC-MS/MS. The Boscalid residues ranged between 0.12 and
0.53 μg kg−1with a field mean of 0.20 ± 0.09 μg kg−1. These results differed
considerably from the predicted field concentration of 16.89 μg kg−1 (calculated from the
application rate) and half-lives (DT50) of 104-182 days compared to 345 days reported in
literature. Adjusting the extraction efficiency to 20% could not explain the large
difference. Therefore, an incubation study with 14C-labeled Boscalid was conducted
to measure the DT50 under controlled conditions. Here, the DT50 values were in
the range of values stated in literature (297-337 days compared to 345 days) but
still much larger than the DT50 based on the field-study values (104-182 days).
Our results indicate that Boscalid dissipation under field conditions is much faster
at agricultural sites with sandy soil type as expected from laboratory incubation
experiments.
Future experiments with Boscalid will be conducted in two different soils with different
particle size. A laboratory experiment with uniformly 13C-labeled Boscalid will provide
insight into the uptake and incorporation in microbial biomass. |
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