In:
Environmental Monitoring and Assessment, Springer Science and Business Media LLC, Vol. 192, No. 2 ( 2020-02)
Abstract:
Glyphosate (GLYP), the globally most important herbicide, may have effects in various compartments of the environment such as soil and water. Although laboratory studies showed fast microbial degradation and a low leaching potential, it is often detected in various environmental compartments, but pathways are unknown. Therefore, the objective was to study GLYP leaching and transformations in a lysimeter field experiment over a study period of one hydrological year using non-radioactive 13 C 2 - 15 N-GLYP labelling and maize cultivation. 15 N and 13 C were selectively measured using isotopic ratio mass spectrometry (IR-MS) in leachates, soil, and plant material. Additionally, HPLC coupled to tandem mass spectrometry (HPLC-MS/MS) was used for quantitation of GLYP and its main degradation product aminomethylphosphonic acid (AMPA) in different environmental compartments (leachates and soil). Results show low recoveries for GLYP ( 〈 3%) and AMPA ( 〈 level of detection) in soil after the study period, whereas recoveries of 15 N (11–19%) and 13 C (23–54%) were higher. Time independent enrichment of 15 N and 13 C and the absence of GLYP and AMPA in leachates indicated further degradation. 15 N was enriched in all compartments of maize plants (roots, shoots, and cobs). 13 C was only enriched in roots. Results confirmed rapid degradation to further degradation products, e.g., 15 NH 4 + , which plausibly was taken up as nutrient by plants. Due to the discrepancy of low GLYP and AMPA concentrations in soil, but higher values for 15 N and 13 C after the study period, it cannot be excluded that non-extractable residues of GLYP remained and accumulated in soil.
Type of Medium:
Online Resource
ISSN:
0167-6369
,
1573-2959
DOI:
10.1007/s10661-019-8045-4
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2020
detail.hit.zdb_id:
2012242-1
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