Environmental behaviour of selected herbicides in a lowland catchment in Northern Germany [Elektronische Ressource] : relevance of inputs via surface runoff and drainage systems into surface water / vorgelegt von Uta Ulrich

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• Naturwissenschaften

Informations

• Publié par: christian-albrechts-universitat_zu_kiel
• Publié le: 01 janvier 2010
• Nombre de lectures: 31
• Langue: English
• Poids de l'ouvrage: 6 Mo

Extrait

Environmental behaviour of selected
Herbicides in a lowland catchment in
Northern Germany
Relevance of inputs via surface runoff and
drainage systems into surface water
Dissertation
zur Erlangung des Doktorgrades
der Mathematisch-Naturwissenschaftlichen Fakultät
der Christian-Albrechts-Universität zu Kiel
vorgelegt von
M.Sc. Uta Ulrich
Kiel, 2010Referentin: Prof. Dr. Nicola Fohrer
Koreferent: Prof. Dr. Hans-Rudolf Bork
Tag der mündlichen Prüfung: 02.02.2011
Zum Druck genehmigt: 02.02.2011
gez. Prof. Dr. Lutz Kipp, DekanACKNOWLEDGEMENT
The accomplishment of this thesis was a big c haand llnuengmerous, people contributed to
the final success. I am grateful to so many people and, hopefully, nobody is forgotten.
My sincere gratitude goes to Prof. Dr. Nicola Fohrer for the initiation of this research, for
her guidance, advices and constructive suggestions.S he provided a working environment for
me to balance my professional and family life.
I would also like to thank Prof. Dr. Hans-Rudolf Bork from the Institut eof Ecosystem Re-
search, Dept. Ecosystem Research and Geoarchaeology, Kiel niUversity, for being the co-ref-
eree.
Without Jürgen Banger from the Landeslabor Neumünster, not a single sample would ha ve
been analyzed. He supported me from the very beginning. His excellent experience was my
rock in turbulent waters, when problems with the chemical analysis devices occurred (what
happened quite often in the beginning). Thank you so much, Christiane Benthe (Landeslabor
Neumünster), who always found the time to discuss my results and gave valuable advices.
Dr. Fred Schulz and Dr. Frank Steinmann, representatives of the LLUR (Landesamt für
Landwirtschaft, Umwelt und ländliche Räume), enabled three projects by funding them. I
would like to express my thanks to them for their open and sincere cooperation.
The farmers in the Kielstau catchment contributed significantly to this the sis as they
provided data and offered sampling sites. My sincere thanks to them, and especially to Jens
Hansen and Thomas Henningsen, for their confidence. Hans-Hermann Jung (local plant pro -
tection agency) made the contact and introduced me to the farmers. Without his guida nce, the
cooperation with the farmers would have been less successful.
What would I have done without my dream-team in the lab? Monika Westphal, Bettina
Hollmann and Sophia Dazert guided me through the bright and dark sides of such a thesi s.
Their psychological support and humor helped me through these periods. Thank you!!!
Hans-Jürgen Voss assisted me in the field and did the sampling of the monit oring projects.
It was always a pleasure to work with him.
iThe surface runoff experiments were conducted at the Lindhof. Thanks to Sabine Mues and
her team who helped, whenever it was necessary, and made life much easier. I also like to
thank Dr. Klink and Mr. Wingen, Institute of Phytopathology, for the pesticide application
during this experiment.
Big thanks go to my student assistants: Piotr Jamrog, the Master of Sample P reparation,
who prepared approx. 900(!) samples; Kamil Patynski with his electronical expertise; Pa ul
Zacharias accomplished the land use mapping of 5000 ha and the following data handling;
Antje Dietrich and Thomas Neugebauer supported the entire surface runoff experiment; Antje
who wrote her master thesis about this topic.
I like to thank Cindy Hugenschmidt for the review, Scott Forsythe for linguistic improv- e
ments and Insa Kühling for formatting the thesis.
All members of the institute contributed during numerous discussions to this thesi s, and
Kerrin Frahm did a very good job organizing all the administrative duties of the projects.
Special thanks go to my husband, my kids and my entire family who supported me with
everything all the time. They always encouraged and reminded me of the really important
things in life!
iiABSTRACT
In order to gain high production levels and product quality, pesticides are employed for the
protection of plants and plant products. By their very nature, however, most pesticides create
harmful risks to humans, animals and the environment. As an example for pesticide beha viour
in lowland conditions, losses of selected pesticides from fields into surface water -were ob
served in the catchment of the Kielstau river. These areas are characterized byflat topography,
shallow groundwater, high proportion of artificial drainages, and a low hyd raulic gradient
causing low flow velocities. Hence, they are sensitive to alterations that result i n changes of
the natural water balance and in-stream water quality. The herbicides Terbuthylazine, Meta-za
chlor and Flufenacet,us ed for corn, rape and winter grain, were monitored on the scales of
field, subcatchment and catchment, each in a single period during spring 2008, autumn 2008
and autumn 2009, respectively. The objective of these observations was the assessment of the
relevance of field drainage to herbicide losses. In daily samples, herbicide c oncentrations
were determined in drainage and groundwater on a drained field, as well as in the Kielstau
and one of its tributaries, the Moorau. Furthermore, precipitation, and discharges of the til e
drainages, of the Kielstau and Moorau were continuously observed. To assess herbicide los ses
in relation to amounts applied, catchment land use was mapped and local far-mers were inter
viewed for herbicide application data. Results from drainage, groundwater, and surface wa ter
in the rivers show concentrations of > 25 ng/l – 301 ng/l for Terbuthylazine, > 25 ng/l –
576 ng/l for Metazachlor and > 30 ng/l – 170 ng/l for Flufenacet. Losses at al-l scales were de
termined as < 0.01 % - 0.01 % of the amount applied for Terbuthylazine, 0.02 – 0.3 % of the
amount applied for Metazachlor and 0.02 – 0.04 % of the amount applied for Flufe nacet. The
pattern of the herbicide concentrations reveal that the compounds were transported into the
drainage and then into surface water during rainfall-induced discharge peaks. Highest- concen
trations were observed during first discharge event(s) after application, but highest daily loa ds
occurred 6 -12 days after application for Terbuthylazine, 32 – 71 days for Metaz achlor and
50 – 53 days for Flufenacet. On the field scale, the relevance of herbicide relocation via dra- in
age was clearly assessed. On the catchment and subcatchment scales, however, it- was im
possible to evaluate all potential pathways. It is assumed that the detected loads ca me mainly
from drainage systems whereas inputs from other pathways were of lesser relevance.
iiiIn addition, as a dislocator of pesticides from fields to water bodies, rainfal-l-induced sur
face runoff was evaluated as a further possible pathway in a laboratory experiment. Repre-
senting lowland characteristicssoi,l-fi lled containers with a slope of 6 % were exposed- to in
termittent artificial rainfa lml mof, 13with six days of rainless period between rainfall events.
This cycle was repeated six times. During one-hour rainfall events, surface runoff wa s
sampled at 10-minute intervals. The samples were analyzed for volume of the wate r phase,
sediment weight, and herbicide concentration of the water phase. Fates of Metazachlor, Terbu-
thylazine and Flufenacet were observed. Maximum concentrations in the water phase of the
surface runoff were 3184 µg Metazachlor/l, 661 µg Terbuthylazine/l and 207 µg Fl ufenacet/l.
Discharged herbicide losses amounted 345to - 440 µg Metazachlor/0.2 m² (plot), 310 - 318
µg Terbuthylazine/0.2 m² and 87 - 111 µg Flufenacet/0.2 m². These loads correspond to
1.92 % and 2.5 % (Metazachlor ), 5.7 – 6.6 % (Terbuthylazine) and 2.1 – 3.8 % (Flufenacet)
of the amount applied. The results show that highest concentrations were observed during the
first interval(s) of surface runoff. But highest loads occurred during the second rainfall event
after surface runoff was generated the first time, when surface runoff volume increased, and
herbicide concentrations were below the maximum. The artificial set up of intermi-ttent rain
fall revealed that, with every new rainfall event after a rainless period, a highe r amount of
herbicides was released from the plot than was released during the last interval of the previous
rainfall event. During the rainless periods, soil surface alterations occurred that caused thi-s ef
fect.
Keywords: herbicides, lowland catchment, drainage systems, surface runoff, intermitte-nt rain
fall
ivZUSAMMENFASSUNG
Pflanzenschutzmittel werden weltweit eingesetzt, um einen hohen Ernteertrag, aber auch um
eine gute Produktqualität zu gewährleisten. Aufgrund ihrer Eigenschaften stellen sie jedoch
ein Gefährdungspotenzial für Mensch, Tier und Umwelt dar. Daher wurde das Austragsverhal -
ten ausgewählter Herbizide von landwirtschaftlichen Flächen in Oberflächengewässe r in
einem Einzugsgebiet der Norddeutschen Tiefebene exemplarisch im Kielstau-Einzugsgebiet
untersucht. Charakteristisch für das Tiefland sind eine flache Topographie, oberflächennahes
Grundwasser, ein hoher Anteil an künstlichen Drainagen und ein niedriger hydraulischer
Gradient, der nur geringe Fließgeschwindigkeiten hervorruft. Aufgrund dieser Merkmale re -