Miljøudvalget 2011-12
MIU Alm.del Bilag 8
Offentligt
The Danish PesticideLeaching AssessmentProgrammeMonitoring results May 1999–June 2010
Jeanne Kjær, Annette E. Rosenbom, Walter Brüsch, René K. Juhler,Lasse Gudmundsson, Finn Plauborg, Ruth Grant and Preben Olsen
Geological Survey of Denmark and GreenlandMinistry of Climate and EnergyDepartment of AgroecologyAarhus UniversityDepartment of BioscienceAarhus University
Editor:Jeanne KjærCover photo:Lasse GudmundssonCover:Henrik Klinge PedersenLayout and graphic production:AuthorsPrinted:September 2011Price:DKK 200ISBN 978-87-7871-312-4Available from:Geological Survey of Denmark and GreenlandØster Voldgade 10, DK-1350 Copenhagen K, DenmarkPhone: +45 38 14 20 00. Fax: +45 38 14 20 50E-mail: [email protected]Homepage: www.geus.dkThe report is also available as a pdf file at www.pesticidvarsling.dk� De Nationale Geologiske Undersøgelser for Danmark og Grønland, 2011
Table of contentsPREFACESUMMARYDANSK SAMMENDRAG1INTRODUCTION .......................................................................................................................... 131.11.22OBJECTIVE............................................................................................................................... 13STRUCTURE OF THEPLAP ....................................................................................................... 14
PESTICIDE LEACHING AT TYLSTRUP.................................................................................. 172.1MATERIALS AND METHODS...................................................................................................... 172.1.1Site description and monitoring design .............................................................................. 172.1.2Agricultural management ................................................................................................... 182.1.3Model setup and calibration ............................................................................................... 182.2RESULTS AND DISCUSSION....................................................................................................... 192.2.1Soil water dynamics and water balances ............................................................................ 192.2.2Bromide leaching................................................................................................................ 212.2.3Pesticide leaching ............................................................................................................... 23
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PESTICIDE LEACHING AT JYNDEVAD ................................................................................. 293.1MATERIALS AND METHODS...................................................................................................... 293.1.1Site description and monitoring design .............................................................................. 293.1.2Agricultural management ................................................................................................... 293.1.3Model setup and calibration ............................................................................................... 313.2RESULTS AND DISCUSSION....................................................................................................... 333.2.1Soil water dynamics and water balances ............................................................................ 333.2.2Bromide leaching................................................................................................................ 343.2.3Pesticide leaching ............................................................................................................... 36
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PESTICIDE LEACHING AT SILSTRUP ................................................................................... 434.1MATERIALS AND METHODS...................................................................................................... 434.1.1Site description and monitoring design .............................................................................. 434.1.2Agricultural management ................................................................................................... 434.1.3Model setup and calibration ............................................................................................... 454.2RESULTS AND DISCUSSION....................................................................................................... 464.2.1Soil water dynamics and water balances ............................................................................ 464.2.2Bromide leaching................................................................................................................ 494.2.3Pesticide leaching ............................................................................................................... 50
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PESTICIDE LEACHING AT ESTRUP ....................................................................................... 615.1MATERIALS AND METHODS...................................................................................................... 615.1.1Site description and monitoring design .............................................................................. 615.1.2Agricultural management ................................................................................................... 615.1.3Model setup and calibration ............................................................................................... 635.2RESULTS AND DISCUSSION....................................................................................................... 635.2.1Soil water dynamics and water balances ............................................................................ 635.2.2Bromide leaching................................................................................................................ 665.2.3Pesticide leaching ............................................................................................................... 67
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PESTICIDE LEACHING AT FAARDRUP ................................................................................. 776.1MATERIALS AND METHODS...................................................................................................... 776.1.1Site description and monitoring design .............................................................................. 776.1.2Agricultural management ................................................................................................... 806.1.3Model setup and calibration ............................................................................................... 806.2RESULTS AND DISCUSSION....................................................................................................... 816.2.1Soil water dynamics and water balances ............................................................................ 816.2.2Bromide leaching................................................................................................................ 836.2.3Pesticide leaching ............................................................................................................... 85
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PESTICIDE ANALYSIS QUALITY ASSURANCE ................................................................... 897.1MATERIALS AND METHODS...................................................................................................... 897.1.1Internal QA ......................................................................................................................... 897.1.2External QA ........................................................................................................................ 897.2RESULTS AND DISCUSSION....................................................................................................... 907.2.1Internal QA ......................................................................................................................... 907.2.2External QA ........................................................................................................................ 927.3SUMMARY AND CONCLUDING REMARKS.................................................................................. 94
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SUMMARY OF MONITORING RESULTS ............................................................................... 95REFERENCES.............................................................................................................................. 107
APPENDIX1.CHEMICAL ABSTRACTS NOMENCLATURE FOR THE PESTICIDES ENCOMPASSED BY THEPLAP.APPENDIX2.PESTICIDE MONITORING PROGRAMME- SAMPLING PROCEDURE.APPENDIX3.AGRICULTURAL MANAGEMENT.APPENDIX4.PRECIPITATION DATA FOR THEPLAPSITES.APPENDIX5.PESTICIDE DETECTION IN SAMPLES FROM DRAINAGE SYSTEM,SUCTION CUPS AND MONITORING SCREENS.APPENDIX6.LABORATORY INTERNAL CONTROL CARDS.
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Preface
In 1998, the Danish Parliament initiated the Danish Pesticide Leaching AssessmentProgramme (PLAP), an intensive monitoring programme aimed at evaluating theleaching risk of pesticides under field conditions. The Danish Government funded thefirst phase of the programme from 1998 to 2001. The programme has now beenprolonged twice, initially with funding from the Ministry of the Environment and theMinistry of Food, Agriculture and Fisheries for the period 2002 to 2009, and presentlywith funding from the Danish Environmental Protection Agency for the period 2010 to2015.The work was conducted by the Geological Survey of Denmark and Greenland(GEUS), the Department of Agroecology (DJF) at Aarhus University and theDepartment of Bioscience (NERI), Aarhus University under the direction of amanagement group comprising Jeanne Kjær (GEUS), Annette E. Rosenbom (GEUS),Walter Brüsch (GEUS), Lis Wollesen de Jonge (DJF), Preben Olsen (DJF), Ruth Grant(NERI) and Steen Marcher (Danish Environmental Protection Agency).This report presents the results for the period May 1999–June 2010. Results coveringpart of the period May 1999–June 2009 have been reported previously (Kjæret al.,2002, Kjæret al.,2003, Kjæret al.,2004, Kjæret al.,2005c, Kjæret al.,2007, Kjæretal.,2008, Kjæret al.,2009, and Rosenbomet al.,2010b). The present report shouldtherefore be seen as a continuation of previous reports with the main focus on theleaching risk of pesticides applied during 2008.The report was prepared jointly by Annette E. Rosenbom, Walter Brüsch, René K.Juhler, Jeanne Kjær, and Lasse Gudmundsson (all GEUS), Preben Olsen, and FinnPlauborg (DJF), and Ruth Grant (NERI). While all authors contributed to the wholereport, authors were responsible for separate aspects as follows:••Pesticide and bromide leaching: Walter Brüsch, Preben Olsen and Jeanne Kjær.Soil water dynamics and water balances: Annette E. Rosenbom, Finn Plauborg, andRuth Grant.•Pesticide analysis quality assurance: René K. Juhler.
Jeanne KjærSeptember 2011
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SummaryIn 1998, the Danish Parliament initiated the Pesticide Leaching Assessment Programme(PLAP), an intensive monitoring programme aimed at evaluating the leaching risk ofpesticides under field conditions. The objective of the PLAP is to improve the scientificfoundation for decision-making in the Danish regulation of pesticides. The specific aimis to analyse whether pesticides applied in accordance with current regulations leach togroundwater in unacceptable concentrations. The programme currently evaluates theleaching risk of 42 pesticides and 41 degradation products at five agricultural sitesranging in size from 1.1 to 2.4 ha. The evaluation is based upon monitoring resultsrepresenting detections in 1 meters depth (water collected via drains and suction cups)and detections in groundwater monitoring screens (1.5-4.5 meter below ground surface,hereafter m b.g.s.). This report presents the results for the entire monitoring period May1999–June 2010. Results covering part of the period May 1999–June 2009 have beenreported previously.Highlights frommonitoring period 2009-2010where6pesticides were applied, showthat:•Bifenox acid (degradation product of bifenox) can on loamy soil leach through theroot zone and enter both drainage water system and groundwater monitoring wells inconcentrations exceeding 0.1 �g/l. Average concentration in the drainage waterexceeded 0.1 �g/l and concentrations exceeding 0.1 �g/l were observed up to sixmonths after application. Similar evidence of pronounced leaching wasnotobservedon the coarse sandy soil as there was only a single detection of bifenox acid in soilwater, whereas bifenox was detected very sporadically in soil and groundwater,concentrations always less than 0.1 �g/l.Ethofumesate, this year used in a new admissible dose that is five times lower thanin past applications, was detected once in groundwater, concentrations at less than0.1 �g/l. When, in the past (before the imposed regulation), ethofumesate was usedat a much higher dose, leaching above 0.1 �g/l to both drains and groundwatermonitoring wells was observed.Metamitron, this year used in a dose 33% lower than the permitted, did not causeleaching above 0.1 �g/l of either metamitron or its metabolite metamitron–desamino. When, in the past, metamitron was used at maximum allowed dose,leaching above 0.1 �g/l to both drainage system and groundwater monitoring wellswas observed. It is not possible to say if the low leaching this year is related to theclimatic conditions/timing or the reduced dose.The leaching pattern of the remaining three pesticides (bentazone, azoxystrobin,triasulfuron) was in line with the previous observations (outlined below).
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The results of theentire monitoring period 1999-2010covering 42 pesticides, showthat:•Of the 42 pesticides applied, 11 pesticides and/or their degradation product(s)(clopyralid, chlormequat, desmedipham, fenpropimorph, florasulam, iodosulfuron-methyl-sodium, linuron, metsulfuron-methyl, thiamethoxam, tribenuron-methyl, andtriasulfuron) did not leach during the entire monitoring period.•The monitoring data indicate pronounced leaching of 14 of the applied pesticidesand/or their degradation products. The following compounds leached through thesoil entering drains and suction cups (placed 1 m b.g.s) in average concentrationsexceeding 0.1 �g/l:ooooooooooooooazoxystrobinand its degradation productCyPM,bentazoneCL153815(degradation product of picolinafen)pirimicarb-desmethyl-formamido(degradation product of pirimicarb)propyzamidetebuconazoleglyphosateand its degradation productAMPAPPU(degradation products of rimsulfuron)Bifenox acid(degradation product of bifenox)ethofumesateTFMP(degradation product of fluazifop-P-butyl)metamitronand its degradation productmetamitron-desaminometribuzin-desamino-diketoandmetribuzin-diketo(degradationproducts of metribuzin)terbuthylazineand its degradation products:desethyl-terbuthylazine,2-hydroxy-desethyl-terbuthylazine,and2-hydroxy-terbuthylazine
For the pesticides and/or their degradation productsmarked in Italics,pronouncedleaching is mainly confined to the depth of 1 meter, where pesticides werefrequently found in samples collected from drains and suction cups, while a limitednumber of detections (fewer than 5 samples per field) exceeding 0.1 �g/l were foundin groundwater monitoring wells. For the pesticides and/or their degradationproductsmarked in bold,pronounced leaching below the depth of 1 m wasobserved. Apart from PPU, these were all frequently detected in concentrationsexceeding 0.1 �g/l in groundwater monitoring wells, exceedance of 0.1 �g/l beingobserved more than six months after application. Although PPU was only detectedin a few samples in concentrations exceeding 0.1 �g/l, elevated concentrations justbelow 0.1 �g/l were found in groundwater monitoring wells during a twoyearperiod, thus confirming the pronounced leaching and high persistency of PPU in soiland groundwater. Repeated applications of PPU may thus pose a contamination riskof the shallow groundwater. Moreover, for the glyphosate being frequently appliedon one loamy soil, detections in groundwater monitoring wells have graduallyincreased over time. On two occasions heavy rain events and snowmelt inducedleaching to the groundwater monitoring wells in concentrations exceeding 0.1 �g/lmore than two years after the application.
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The monitoring data also indicate leaching of an additional 17 pesticides, but in lowconcentrations. Although concentrations exceeded 0.1 �g/l in several samplescollected from suction cups and drains (1 m b.g.s.), average leaching concentrationson a yearly basis did not. None of the compounds were found in groundwatermonitoring wells in concentrations exceeding 0.1 �g/l.
The PLAP initially evaluated the leaching risk at six agricultural sites representing arange of Danish soil and climate conditions. Monitoring at the Slaeggerup site wasterminated on 1 July 2003, and results from that site are not included in the presentreport. For the monitoring results from this site see Kjæret al.(2004).In order to describe water transport, a bromide tracer was applied to the fields. Bromideand pesticide concentrations are measured monthly in both the unsaturated and thesaturated zones, and weekly in the drainage water. This report covers the period May1999–June 2010 and presents the monitoring results from the five agricultural sitespresently monitored. The main focus is on evaluating the leaching risk of the pesticidesapplied during 2008.
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Dansk sammendragI 1998 vedtog Folketinget at iværksætte projektet ”Varslingssystem for udvaskning afPesticider til grundvandet” (VAP). VAP er et omfattende moniteringsprogram, derundersøger udvaskning af pesticider anvendt i landbrug under reelle markforhold.Programmet har til formål at undersøge, om godkendte pesticider eller deresnedbrydningsprodukter – ved regelret brug – udvaskes til grundvandet i koncentrationerover grænseværdien for herigennem at udvide det videnskabelige grundlag for danskemyndigheders (Miljøstyrelsen) procedurer for regulering af sprøjtemidler.Udvaskningsrisikoen for 42 pesticider og 41 nedbrydningsprodukter er således op til idag undersøgt på fem marker, der har en størrelse på mellem 1,1 og 2,4 ha.Undersøgelsen bygger på moniteringsresultater henholdsvis repræsenterende fund i enmeters dybde (indhentet via dræn og sugeceller) og fund i grundvandsmoniteringsfiltre(1.5-4.5 meter under terræn, herefter m u.t.). Denne rapport opsummerer resultaterne forden samlede moniteringsperiode maj 1999 – juni 2010; resultater fra de foregående årmaj 1999 – juni 2009 er blevet afrapporteret i de tidligere rapporter.”Highlights” fra den seneste moniteringsperiode2009-2010,hvor6pesticider blevudbragt, viser følgende:•Bifenox-syre (nedbrydningsprodukt af bifenox) blev på lerjorde udvasket frarodzonen (1 m.u.t.) til både dræn og grundvandsfiltre i koncentrationer over 0,1 �g/l.I drænene oversteg den årlige middelkoncentration 0,1 �g/l, og i grundvandsfiltreneblev der på en ud af to testede lerjorde fundet koncentrationer over 0,1 �g/l op tilseks måneder efter udbringning. Tilsvarende udvaskning blev ikke set på dengrovsandede jord, hvor der kun var et enkelt fund af bifenox-syre (i jordvandet) samtsporadiske fund af bifenox i lave koncentrationer (under 0,1 �g/l).Ethofumesat, der som følge af Miljøstyrelsens restriktioner dette år blev udbragt i endosis 5 gange lavere end tidligere, blev denne gang kun fundet i en enkelt prøve(<0,1 �g/l). Ved tidligere anvendelser med den høje dosering, blev ethofumesatudvasket til både dræn og grundvandsfiltre i koncentrationer over 0,1 �g/l.Metamitron, som dette år blev udbragt i den anbefalede dosis, hvilket var 33%mindre end den maximalt tilladte mængde, blev ikke udvasket i koncentrationer, deroversteg 0,1 �g/l. Ved tidligere udbringninger (ved den maximalt tilladte dosis) blevmetamitron og dets nedbrydningsprodukt metamitron-desamino udvasket ikoncentrationer der oversteg 0,1 �g/l i både dræn og grundvandsfiltre. Det erimidlertid ikke til at sige om den mindskede udvaskning dette år skyldes den laveredosering eller de klimatiske forhold.For de øvrige 3 stoffer (bentazon, azoxystrobin, triasulfuron) var de observeredeudvaskningsforløb meget lig tidligere observationer (beskrevet nedenfor).
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Resultater for helemoniteringsperioden 1999-2010,som omfatter42pesticider viserfølgende:
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Af de 42 pesticider, der er blevet udbragt, blev 11 pesticider ellernedbrydningsprodukterheraf(clopyralid,chlormequat,desmedipham,fenpropimorph, florasulam, iodosulfuron-methyl-natrium, linuron, metsulfuron-methyl, thiamethoxam, tribenuronmethyl og triasulfuron)ikkefundet udvasket iløbet af den samlede moniteringsperiode.14 af de udbragte stoffer eller nedbrydningsprodukter heraf gav anledning til enmarkant udvaskning. Følgende stoffer blev udvasket til dræn og sugeceller,beliggende i ca. 1 meters dybde i gennemsnitskoncentrationer over 0,1 �g/l:oooooooooooooazoxystrobinog dets nedbrydningsproduktCyPMbentazonCL153815(nedbrydningsprodukt af picolinafen)pirimicarb-desmethyl-formamido(nedbrydningsprodukt af pirimicarb)propyzamidtebuconazolglyphosatog dets nedbrydningsproduktAMPAPPU(nedbrydningsprodukt af rimsulfuron)bifenox-syre(nedbrydningsprodukt af bifenox)ethofumesatTFMP(nedbrydningsprodukt af fluazifop-P-butyl),metamitronog dets nedbrydningsproduktmetamitron-desaminometribuzin-desamino-diketoogmetribuzin-diketo(nedbrydningsprodukter af metribuzin)oterbuthylazinog dets nedbrydningsprodukterdesethyl-terbuthylazin,2-hydroxy-desethyl-terbuthylazin, and 2-hydroxy-terbuthylazin
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For de pesticider eller nedbrydningsprodukter heraf fremhævet medkursivvarudvaskningen primært begrænset til 1 m.u.t., hvor de blev fundet hyppigt i dræn ogsugeceller. Selvom hovedparten af stofferne blev fundet i koncentrationer over 0,1�g/l i grundvandsfiltrene, var antallet af overskridelser få (mindre end 5 pr. mark).Pesticider markeret medfedblev derimod udvasket til grundvandsfiltrene i en størregrad. På nær PPU blev samtlige stoffer relativt hyppigt fundet i koncentrationer over0,1 �g/l i grundvandsfiltrene, hvor koncentrationer over 0,1 �g/l blev fundet mereend seks måneder efter udbringning. Om end det kun var enkelte prøver somindeholdt mere end 0,1 �g/l PPU, blev der igennem en toårig periode fundet PPU igrundvandet i koncentrationer tæt på de 0,1 �g/l, hvilket bekræfter den højepersistens af PPU i jord og grundvand. Gentagne udbringninger af PPU kanpotentielt forurene det allerøverste grundvand. Glyphosat er blevet udbragt fleregange på en af de lerede forsøgslokaliteter. På denne mark er der igennem de senesteår konstateret et stigende antal fund af glyphosat i grundvandsfiltrene. To gange harmarkante nedbørshændelse samt snesmeltning forårsaget udvaskning af glyphosat tilgrundvandfiltrene i koncentrationer over 0,1 �g/l mere end to år efter udbringning.•Andre 17 stoffer gav anledning til udvaskning. Selv om flere af disse stoffer i énmeters dybde ofte blev fundet i koncentrationer over 0,1 �g/l, var der ikke tale om,at udvaskningen som årsmiddel oversteg 0,1 �g/l. Stofferne blev heller ikke fundet igrundvandsfiltrene i koncentration over 0.1 �g/L.
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VAP-programmet omfattede oprindeligt seks marker placeret, så de repræsentererforskellige typer geologi og tillige tager hensyn til de klimatiske variationer i Danmark,specielt hvad angår nedbørforhold. Monitering på den ene forsøgsmark (Slæggerup)stoppede 1. juli, 2003. Resultater fra denne mark er ikke inkluderet i denne rapport, menkan findes i Kjæret al.(2004). De anvendte pesticider bliver udbragt i maksimalttilladte doser. Bromid anvendes som sporstof for at beskrive vandtransporten. Bromid-og pesticidkoncentrationer bliver analyseret månedligt i prøver udtaget i den umættedeog mættede zone og ugentligt i prøver af drænvand. I denne rapport præsenteresmoniteringsresultaterne for de fem områder for perioden maj 1999 - juni 2010 primærtmed fokus på pesticider udbragt i 2008. En del af stofferne har kun været inkluderet imoniteringsprogrammet i én udvaskningssæson, og for disse er det derfor for tidligt atkonkludere noget endeligt.
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1 Introduction
There is growing public concern in Denmark about pesticide contamination of oursurface waters and groundwater. Pesticides and their degradation products haveincreasingly been detected in groundwater during the past decade and are now presentin much of the Danish groundwater. Under the Danish National GroundwaterMonitoring Programme (GRUMO) pesticides have so far been detected in 53% of allscreens monitored and in 61% of the screens placed in the upper groundwater (Thorling,L. (red), 2010).The increasing detection of pesticides in groundwater over the past 10 years has givenrise to the desire to enhance the scientific foundation for the existing approval procedurefor pesticides and to improve the present risk assessment tools. A main issue in thisrespect is that the EU assessment and hence also the Danish assessment of the risk ofpesticide leaching to groundwater is largely based on data from modelling, laboratory orlysimeter studies. However, these types of data may not adequately describe theleaching that may occur under actual field conditions. Although models are widely usedwithin the registration process, their validation requires further work, not least becauseof the limited availability of field data (Boesten, 2000). Moreover, laboratory andlysimeter studies do not include the spatial variability of the soil parameters (hydraulic,chemical, physical and microbiological soil properties) affecting pesticide leaching.This is of particular importance for silty and loamy soils, where preferential transportmay have a major impact on pesticide leaching. In fact, various field studies suggest thatconsiderable preferential transport of several pesticides occurs to a depth of 1 m underconditions comparable to those pertaining in Denmark (Kördel, 1997).The inclusion of field studies, i.e. test plots exceeding 1 ha, in risk assessment ofpesticide leaching to groundwater is considered an important improvement to the riskassessment procedures. For example, the US Environmental Protection Agency (US-EPA) has included field-scale studies in its risk assessments since 1987. Pesticides thatmay potentially leach to the groundwater are required to be included in field studies aspart of the registration procedure. The US-EPA has therefore conducted field studies onmore than 50 pesticides (US Environmental Protection Agency, 1998). A similarconcept has also been adopted within the European Union (EU), where Directive91/414/EEC, Annexe VI (Council Directive 97/57/EC of 22 September 1997) enablesfield leaching study results to be included in the risk assessments.
1.1 ObjectiveIn 1998, the Danish Government initiated the Pesticide Leaching AssessmentProgramme (PLAP), an intensive monitoring programme with the purpose of evaluatingthe leaching risk of pesticides under field conditions. The PLAP is intended to serve asan early warning system providing decision-makers with advance warning if approvedpesticides leach in unacceptable concentrations. The programme focuses on pesticides
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used in arable farming and monitors leaching at five agricultural test sites representativeof Danish conditions.The objective of the PLAP is to improve the scientific foundation for decision-makingin the Danish registration and approval procedures for pesticides, enabling field studiesto be included in risk assessment of selected pesticides. The specific aim is to analysewhether pesticides applied in accordance with current regulations leach at levelsexceeding the maximum allowable concentration of 0.1 �g/l.
1.2 Structure of the PLAPThe pesticides included in the PLAP were selected by the Danish EnvironmentalProtection Agency on the basis of expert judgement. At present, 42 pesticides and 41degradation products are included in the PLAP. All the compounds analysed are listedin Appendix 1.
Figure 1.Location of the PLAP sitesTylstrup, Jyndevad, Silstrup, Estrup,andFaardrup.Monitoring atSlaeggerup was terminated on 1 July 2003.
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Soil type and climatic conditions are considered to be some of the most importantparameters controlling pesticide leaching. The PLAP initially encompassed six test sitesrepresentative of the dominant soil types and the climatic conditions in Denmark(Figure 1). Monitoring at the Slaeggerup site was terminated on 1 July 2003, and resultsfrom that site are not included in the present report. For the monitoring results from thissite see Kjæret al.(2003). The groundwater table at all the sites is shallow, therebyenabling pesticide leaching to groundwater to be rapidly detected (Table 1). Cultivationof the PLAP sites is in line with conventional agricultural practice in the vicinity. Thepesticides are applied at maximum permitted doses and in the manner specified in theregulations. Hence any pesticides or degradation products appearing in the groundwaterdownstream of the sites can be related to the current approval conditions pertaining tothe individual pesticides. The PLAP was initiated in autumn 1998. The five test sitesencompassed by the present report were selected and established during 1999.Monitoring was initiated at Tylstrup, Jyndevad and Faardrup in 1999 and at Silstrup andEstrup in 2000 (Table 1).Table 1.Characteristics of the five PLAP sites (modified from Lindhardtet al.,2001).TylstrupJyndevadSilstrupLocationPrecipitationW x L (m)Area (ha)Tile drainDepths to tile drain (m b.g.s.)Monitoring initiatedGeological characteristics– Deposited by– Sediment type– DGU symbol– Depth to the calcareousmatrix (m b.g.s.)– Depth to the reduced matrix (m b.g.s.)– Max. fracture depth3)(m)– Fracture intensity 3–4 m depth(fractures/m)– Ks in C horizon (m/s)Topsoil characteristics– DK classification– Classification– Clay content (%)– Silt content (%)– Sand content (%)– pH– TOC (%)1)1)
EstrupAskov862543105 x 1201.3Yes1.1
FaardrupSlagelse558585150 x 1602.3Yes1.2
Brønderslev(mm/y)66855270 x 1661.1NoMay 1999Saltwater
Tinglev858555135 x 1842.4NoSep 1999Meltwater
Thisted86656491 x 1851.7Yes1.1
Pot. evapotransp.1)(mm/y)
Apr 2000GlacierClayey tillML1.354<13.4¶10-6JB7Sandy clay loam/sandy loam18–262786.7–72.2
Apr 2000Glacier/meltwaterClayey tillML1–42)>52)>6.5118.0¶10-8JB5/6Sandy loam10–2020–2750–656.5–7.81.7–7.3
Sep 1999GlacierClayey tillML1.54.2847.2¶10-6JB5/6Sandy loam14–1525576.4–6.61.4
Fine sand Coarse sandYSTS6>12––2.0¶10-5JB2Loamy sand613784–4.52.05–910–12––1.3¶10-4JB1Sand54885.6–6.21.8
Yearly normal based on a time series for the period 1961–90. The data refer to precipitation measured 1.5 m aboveground.2)Large variation within the field.3)Maximum fracture depth refers to the maximum fracture depth found in excavations and wells.
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Site characterization and monitoring design are described in detail in Lindhardtet al.(2001). The present report presents the results of the monitoring period May 1999–June2009. The main focus of this report is on the leaching risk of pesticides applied during2007. For a detailed description of the earlier part of the monitoring period (May 1999–June 2009), see previous publications onhttp://pesticidvarsling.dk/publ_result-/index.html.Under the PLAP the leaching risk of pesticides is evaluated on the basis of at least twoyears of monitoring data. For some pesticides the present report must be consideredpreliminary because they have been monitored for an insufficient length of time.Hydrological modelling of the unsaturated zone at each PLAP site supports themonitoring data. The MACRO model (version 5.1), see Larsboet al.(2005), was usedto describe the soil water dynamics at each site during the entire monitoring period fromMay 1999–June 2010. The five site models have been calibrated for the monitoringperiod May 1999–June 2004 and validated for the monitoring period July 2004–June2010.Scientifically valid methods of analysis are essential to ensure the integrity of the PLAP.The field monitoring work has therefore been supported by intensive quality assuranceentailing continuous evaluation of the analyses employed. The quality assurancemethodology and results are presented in Section 7.
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2 Pesticide leaching at Tylstrup
2.1
Materials and methods
2.1.1 Site description and monitoring designTylstrup is located in northern Jutland (Figure 1). The test field covers a cultivated areaof 1.1 ha (70 x 166 m) and is practically flat, with windbreaks bordering the eastern andwestern sides. Based on two soil profiles dug in the buffer zone around the test field thesoil was classified as a Humic Psammentic Dystrudept (Soil Survey Staff, 1999). Thetopsoil is characterised as loamy sand with 6% clay and 2.0% total organic carbon(Table 1). The aquifer material consists of an approx. 20 m deep layer of marine sandsediment deposited in the Yoldia Sea. The southern part is rather homogeneous,consisting entirely of fine-grained sand, whereas the northern part is moreheterogeneous due to the intrusion of several silt and clay lenses (Lindhardtet al.,2001). The overall direction of groundwater flow is towards the west (Figure 2). Duringthe monitoring period the groundwater table was 2.6–4.5 m b.g.s. (Figure 3). A briefdescription of the sampling procedure is provided in Appendix 2. The monitoringdesign and test site are described in detail in Lindhardtet al.(2001), and the analysismethods in Kjæret al.(2002).
Figure 2.Overviewof theTylstrupsite. The innermost white area indicates the cultivated land, while the grey areaindicates the surrounding buffer zone. The positions of the various installations are indicated, as is the direction ofgroundwater flow (by an arrow). Pesticide monitoring is conducted monthly and half-yearly from suction cups andselected monitoring wells as described in Table A2.1 in Appendix 2.
17
2.1.2 Agricultural managementManagement practice during the 2009 and 2010 growing seasons is briefly summarizedbelow and detailed in Appendix 3 (Table A3.1). For information about managementpractice during the previous monitoring periods, see previous monitoring reportsavailable on http://pesticidvarsling.dk/publ_result/index.html.The field was ploughed on 10 April 2009 and on 14 April sown with spring barley (cv.Keops), which emerged on 21 April. On 15 May, when the barley had three detectabletillers, the herbicides MCPA and bentazone were applied, of which only the latter wasmonitored. Fungi were treated on 23 June at 80% inflorescence using azoxystrobin, andpests were treated on 8 July at late milk stage using tau-fluvalinate. Tau-fluvalinate andazoxystrobin were not included in the monitoring programme. The barley received 26mm irrigation on 29 June at the end of flowering and 27 mm at late milk stage on 8 July.An amount of 53.4 hkg/ha of grain (85% dry matter (DM)) was harvested on 20 August,slightly above the average for the soil type this year (Plantedirektoratet, 2009). On 28august, 17.4 hkg/ha of straw (100% DM) was removed from the field.On 4 April 2010 the field was ploughed and on 6 May planted with potatoes (cv.Kuras). On 26 May, before emergence, the field was sprayed with the herbicidesaclonifen and rimsulfuron. Rimsulfuron was applied again on 8 June, when the fifth leafof the main stem had unfolded. Cyazofamid was used against fungi six times between15 June and 2 August. On 9 July a fungicide containing mancozeb and metalaxyl wasused, of which only metalaxyl was monitored. Between 9 August and 23 August thefungicide mancozeb was again applied, but not monitored. The crop was irrigated twice,with 29 mm on 6 July and 28 mm on 27 July. The yield of potatoes, harvested on 20October, was 470.3 hkg/ha with 27.2% DM (128.0 hkg/ha at 100% DM), yields beingbelow the average for the year and soil type (Plantedirektoratet 2010).2.1.3 Model setup and calibrationThe numerical model MACRO (version 5.1) was applied to the Tylstrup site coveringthe soil profile to a depth of 5 m b.g.s., always including the groundwater table. Themodel was used to simulate water and bromide transport in the unsaturated zone duringthe full monitoring period May 1999–June 2010 and to establish an annual waterbalance.Compared to Rosenbomet al.(2010b), a year of validation was added to the MACRO-setup for the Tylstrup site. The setup was hereby calibrated for the monitoring periodMay 1999-June 2004 and validated for the monitoring period July 2004-June 2010.Daily time series of groundwater table measured in the piezometers located in the bufferzone, soil water content measured at three different depths (25, 60, and 110 cm b.g.s.)from the two profiles S1 and S2 (Figure 2) and the bromide concentration measured inthe suction cups located 1 and 2 m b.g.s. were used in the calibration and validationprocess. Data acquisition, model setup and results related to simulated bromidetransport are described in Barleboet al.(2007).
18
Table 2.Annual water balance forTylstrup(mm/y). Precipitation is corrected to soil surface according to themethod of Allerup and Madsen (1979).NormalActualGroundwaterprecipitation2)PrecipitationIrrigationevapotranspirationrecharge3)1.5.99–30.6.991)12026901121561.7.99–30.6.007731073334986081.7.00–30.6.01773914754875021.7.01–30.6.02773906805704161.7.02–30.6.03773918235024391.7.03–30.6.0477375804722871.7.04–30.6.05773854574774341.7.05–30.6.06773725674883041.7.06–30.6.077731147595916151.7.07–30.6.087739131265724671.7.08–30.6.097731269266006951.7.09–30.6.10773863274194711)Accumulated for a two-month period.2)Normal values based on time series for 1961–1990.3)Groundwater recharge is calculated as precipitation + irrigation - actual evapotranspiration.
2.2
Results and discussion
2.2.1 Soil water dynamics and water balancesThe model simulations were generally consistent with the observed data, thus indicatinga good model description of the overall soil water dynamics in the unsaturated zone(Figure 3). The overall trends in soil water saturation were modelled successfully, withthe model capturing soil water dynamics at all depths (Figure 3C-E). During the lastthree hydraulic years the level in water saturation at 25 cm b.g.s. was, however,overestimated. Moreover the initial decrease in water saturation observed during thesummer periods at 25, 60, and 110 cm b.g.s. was less well captured. The dynamics ofgroundwater table were captured with some exceptions, but as with previoussimulations the amplitude of the fluctuations was less well described (Figure 3B).The resulting annual water balance is shown for each hydraulic year of the monitoringperiod (July–June) in Table 2. Values for precipitation and actual evapotranspiration forthe most recent hydraulic year, July 2009–June 2010, were among the lowest observedsince monitoring began at the site, and the monthly precipitation pattern for this yearwas low to medium compared with earlier years, except for the wettest Novembermonitored. Especially January was very dry (Appendix 4). Artificial irrigation wasminimal, which could be the result of a wet July. The groundwater recharge/percolationwas medium compared to the other hydraulic years, and continuous (Figure 3A).
19
Figure 3.Soil water dynamics atTylstrup:Measured precipitation, irrigation and simulated percolation 1 m b.g.s.(A), simulated and measured groundwater level GWT (B), and simulated and measured soil water saturation (SWsat.) at three different soil depths (C, D and E). The measured data in B derive from piezometers located in the bufferzone. The measured data in C, D and E derive from TDR probes installed at S1 and S2 (Figure 2). The brokenvertical line indicates the beginning of the validation period (July 2004-June 2010).
20
12ASuction cups - S1
Bromide (mg/l)
9
1 m b.g.s.630
2 m b.g.s.
May-99
May-00
May-01
May-02
May-03
May-04
May-05
May-06
May-07
May-08
May-09
12
Bromide (mg/l)
9630
B
Suction cups - S2
1 m b.g.s.
2 m b.g.s.
May-99
May-00
May-01
May-02
May-03
May-04
May-05
May-06
May-07
May-08
May-09
Figure 4.Measured bromide concentration in the unsaturated zone atTylstrup.The measured data derive fromsuction cups installed 1 m b.g.s. and 2 m b.g.s. at locations S1 (A) and S2 (B) indicated in Figure 2. The greenvertical lines indicate the dates of bromide applications.
2.2.2 Bromide leachingBromide has now been applied twice at Tylstrup. The bromide concentrations measureduntil April 2003 (Figure 4 and Figure 5) relate to the bromide applied in May 1999, asdescribed further in Kjæret al.(2003). Unsaturated transport of the bromide applied inMarch 2003 is evaluated in Barleboet al.(2007).
21
May-10
May-10
Bromide (mg/l)0120312
Bromide (mg/l)
Bromide (mg/l)
Bromide (mg/l)Bromide (mg/l)
Bromide (mg/l)
03
1
2
3
0
1
2
3
4
0
1
2
3
0May-99May-99
1May-99May-99
2
3
May-99
M4M3
M1
M5M2
M6May-00May-00
3-4 m
May-00May-01May-01
May-00May-00
May-01
May-01
May-01
4-5 m
May-02
May-02
May-02May-02
May-02
May-03
May-03
May-03May-03
May-03
5-6 m
Figure 5.Bromide concentration in the groundwater atTylstrup.The data derive from monitoring wells M1–M6.Monitoring at well M6 was suspended September 2008 (Appendix 2). Screen depth is indicated in m b.g.s. The greenvertical lines indicate the dates of bromide applications.
22
May-04
May-04
May-04
May-04
May-04
May-05
May-05
May-05
May-05
May-05
6-7 m
May-06
May-06
May-06
May-06
May-06
May-07
May-07
May-07
May-07
May-07
7-8 m
May-08May-08
May-08
May-08
May-08
8-9 m
May-09May-09
May-09
May-09
May-09
May-10
May-10
May-10
May-10
May-10
2.2.3 Pesticide leachingMonitoring at Tylstrup began in May 1999 and presently encompasses severalpesticides and their degradation products, as shown in Table 3. Pesticide applicationsduring the latest two growing seasons are shown together with precipitation andsimulated precipitation in Figure 6.It should be noted that precipitation in Table 3 is corrected to soil surface according toAllerup and Madsen (1979), whereas percolation (1 m b.g.s.) refers to accumulatedpercolation as simulated with the MACRO model. It should also be noted that some ofthe applied pesticides degrade rapidly, e.g. mancozeb (applied here as Dithane DG),tribenuron-methyl (applied here as Express ST) and rimsulfuron (applied here as Titus).The risk of leaching is therefore associated with their respective degradation products:ETU, triazinamin-methyl, PPU and PPU-desamino. This is why the degradationproducts and not the parent compounds are monitored in PLAP (Table 3). Pesticidesapplied later than April 2010 are not evaluated in this report and hence are not includedin Table 3 and Figure 6.The current report focuses on the pesticide applied from 2008 and onwards, whileleaching risk of pesticides applied before 2008 has been evaluated in previousmonitoring reports (see http://pesticidvarsling.dk/publ_result/index.html). The leachingof metribuzin is further detailed in Kjæret al.(2005b) and Rosenbomet al.(2009).
May
Aug
Nov
Mar
Dec
Apr
Sep
Feb
Oct
Jun
Jan
Jul
0Precipitation (mm/d)
30202008/200915105030202009/2010151050Precipitation & irrigationBentazone (2009)Azoxystrobin (2008 & 2009)Simulated percolation
20304050600
Precipitation (mm/d)
2030405060
Figure 6.Application of pesticides included in the monitoring programme, precipitation and irrigation(primary axis) together with simulated percolation 1 m b.g.s. (secondary axis) atTylstrupin 2008/2009upper) and 2009/2010 (lower).
23
Percolation (mm/d)
10
25
Percolation (mm/d)
10
25
Table 3.Pesticides analysed atTylstrupwith the products used shown in parentheses. Degradation products are initalics. Precipitation (prec.) and percolation (perc.) are accumulated from the date of first application until the end ofmonitoring. 1stmonth perc. refers to accumulated percolation within the first month after the application. Cmeanrefersto average leachate concentration at 1 m b.g.s. the first year after application (See Appendix 2 for calculationmethod).Crop and analysed pesticidesApplication End ofPrec.Perc. 1stmonthCmeanDatemonitoring (mm)(mm) perc. (mm)(�g/L)Potatoes 1999Linuron (Afalon)- ETU1)(Dithane DG)Metribuzine (Sencor WG)- metribuzine-diketo- metribuzine-desamino- metribuzine-desamino-diketoSpring barley 2000Triasulfuron (Logran 20 WG)- triazinaminPropiconazole (Tilt Top)Fenpropimorph (Tilt Top)- fenpropimorphic acidPirimicarb (Pirimor G)- pirimicarb-desmethyl- pirimicarb-desmethyl-formamidoWinter rye 2001Pendimethalin (Stomp SC)Triazinamin-methyl2)(Express)Propiconazole (Tilt Top)Fenpropimorph (Tilt Top)- fenpropimorphic acidMay 99Jun 99Jun 99Jul 01Oct 01Jul 03Jul 10†Jul 03Apr 08Apr 03Jul 03Jul 03Apr 0325502381422311142422386892740294829482622125311692097538720974192128313411341126387738585858513111117<0.01<0.01<0.010.05–0.36<0.020.14–0.97<0.02<0.02<0.01<0.01<0.02<0.01<0.02<0.02<0.01<0.02<0.01<0.01<0.01<0.01<0.02
May 00Jun 00Jun 00Jun 00
Nov 00Nov 00May 01May 01
Apr 03Apr 03Jul 03Jul 03
2271227129482948
1219121913411341
1091091111
Winter rape 2002Clomazone (Command CS)Sep 01- FMC65317( propanamide-clomazone)
Jul 04
2534
1194
9
Systematic chemical nomenclature for the analysed pesticides is given in Appendix 1.1)Degradation product of mancozeb. The parent compound degrades too rapidly to be detected by monitoring.2)Degradation product of tribenuron-methyl. The parent compound degrades too rapidly to be detected by monitoring.† Monitoring will continue during the following year. The values for prec. and perc. are accumulated up to July 2009.
Degradation products of rimsulfuron, which was applied in June 2004, continued toleach also in 2009/2010, but now only in small concentrations. The results of this 2004application are summarised below and in Rosenbomet al.(2010a).Rimsulfuron degrades rapidly in the soil, and the leaching risk is therefore associatedwith the degradation products PPU and PPU-desamino. PPU has been found severaltimes in suction cups situated 1 m and 2 m b.g.s. at both S1 and S2 (Figure 7). The firstdetection of PPU occurred 10 months after the application of rimsulfuron (Figure 7B),after which PPU was found in 122 out of 192 analysed samples with concentrationsranging between 0.017 and 0.150 �g/l. PPU-desamino has been found in 35 out of 192analysed samples with concentrations ranging between 0.01 and 0.042 �g/l. A littlemore than two years after application, PPU was found at 1 m depth at S2, whereafterPPU was detected in 46 out of 99 analysed samples with concentrations rangingbetween 0.01 and 0.067 �g/l (Figure 7D). At S2, the number of detections andconcentration levels of PPU-desamino were low (Figure 7D and 7E; Appendix 5). Smallconcentrations of PPU were seen in both S1 and S2 at the end of the monitoring period,indicating that although leaching had reduced, it had not yet ceased. After application ofrimsulfuron, average concentrations did not exceed 0.1 �g/l in any of the five years foreither of the degradation products (Table 4).
24
Table 3 continued.Pesticides analysed atTylstrupwith the products used shown in parentheses. Degradationproducts are in italics. Precipitation (prec.) and percolation (perc.) are accumulated from date of first application untilthe end of monitoring. 1stmonth perc. refers to accumulated percolation within the first month after the application.Cmeanrefers to average leachate concentration at 1 m b.g.s. the first year after application (See Appendix 2 forcalculation method).Crop and analysed pesticidesApplication End ofPrec. Perc. 1stmonthCmeandatemonitoring (mm) (mm) perc. (mm) (�g/l)Winter wheat 2003Bromoxynil (Oxitril CM)Ioxynil (Oxitril CM)Fluroxypyr (Starane 180)Flamprop-M-isopropyl (Barnon Plus 3)- Flamprop-M (free acid)Dimethoate (Perfekthion 500 S)Oct 02Oct 02May 03May 03Jul 03Apr 05Apr 05Jul 05Jul 05Jul 05Jul 06Jul 10†Jul 10†Jul 07208220821867263516291754621162112145995995787103172270430083008933535350421416131316<0.01<0.01<0.02<0.01<0.01<0.01<0.013)<0.013)<0.01<0.01<0.01<0.014)<0.01<0.01<0.01<0.02<0.01<0.01<0.02<0.01<0.01<0.01<0.01<0.01<0.01<0.01<0.01<0.01<0.01<0.01<0.01
Potatoes 2004-Fluazifop-P (free acid)1)(Fusilade X-tra) May 04- PPU2)(Titus)Jun 042)- PPU-desamino(Titus)Jun 04Maize 2005Terbuthylazine (Inter-Terbutylazine)-desethyl-terbuthylazine-2-hydroxy-terbuthylazine-desisopropyl-atrazine-2-hydroxy-desethyl-terbuthylazineBentazone (Laddok TE)-AIBASpring barley 2006-triazinamin-methyl5)(Express ST)Epoxiconazole (Opus)Winter rape 2007Thiamethoxam (Cruiser RAPS)6)-CGA 322704Propyzamide (Kerb 500 SC)-RH-24644-RH-24580-RH-24655Clopyralid (Matrigon)Winter wheat 2008Pendimethalin (Stomp)Tebuconazole (Folicur EC250)Azoxystrobin (Amistar)-CyPMSpring barley 2009Bentazone (Basagran M75)Azoxystrobin (Amistar)-CyPMMay 05
Jun 05
Jul 07
2061
927
33
Jun 06Jul 06Aug 06Feb 07
Jul 08Jul 08Apr 08Apr 09
2349223320302400
1184114811231172
43245740
Mar 07Oct 07Nov 07Jun 08
Apr 09Dec 09Mar 10Jul 10†
2317259526962265
1112132414271151
2427460
May 09Jun 09
Jul 10†Jul 10†
1084920
512485
2211
Systematic chemical nomenclature for the analysed pesticides is given in Appendix 1.1)Degradation product of fluazifop-P-butyl. The parent compound degrades too rapidly to be detected by monitoring.2)Degradation product of rimsulfuron. The parent compound degrades too rapidly to be detected by monitoring.3)Leaching increased the second and third year after application (see Figure 7 and Table 4).4)Leaching increased during the second year after application but measured concentrations did not exceed 0.042 �g/l (seeKjær et al., 2008).5)Degradation product of tribenuron-methyl. The parent compound degrades too rapidly to be detected by monitoring.6)Unlike the other pesticide applied via surface spray application, thiamethoxam was directly applied in the soil as the rapeseeds (cv. Lioness) were dressed with thiamethoxam.† Monitoring will continue during the following year. The values for prec. and perc. are accumulated up to July 2009.
PPU was found in two groundwater samples (0.045 �g/l on 7 December 2005 in themonitoring screen of M4 located 4.4-5.4 m b.g.s. and 0.011 �g/l on 11 February 2009 inM5.5). PPU-desamino has not been detected in the groundwater (Table A5.1 inAppendix 5).
25
Precipitation & irrigationMay-04May-06Sep-05Jan-05Jan-07
Simulated percolationFeb-09Oct-07Oct-09Jun-08Jun-10
Precipitation (mm/d)
1020304050600.2A
2520151050Suction cups - S11 m b.g.sB
Pesticide (�g/l)
0.1
0.0Pesticide (�g/l)
0.2Suction cups - S12 m b.g.s0.1C
Pesticide (�g/l)
0.00.2Suction cups - S21 m b.g.sD
0.1
Pesticide (�g/l)
0.00.20.10.0Suction cups - S22 m b.g.sE
May-04
May-06
Sep-05
Oct-07
Feb-09
Oct-09
Jan-05
Jan-07
Jun-08
PPU
PPU-desamido
Figure 7.Precipitation, irrigation and simulated percolation 1 m b.g.s. (A) together with measuredconcentration ofPPUandPPU–desamino(�g/l) in suction cups installed at location S1 at 1 m b.g.s. (B)and 2 m b.g.s. (C) and location S2 at 1 m b.g.s. (D) and 2 m b.g.s. (E) atTylstrup.The green vertical lineindicates the date of pesticide application. Open symbols indicate concentrations below the limit ofdetection (0.02 �g/l prior to July 2006 and 0.01 �g/l thereafter). While PPU-desamino has not beendetected in the groundwater, PPU was detected in two groundwater samples (see text).
26
Jun-10
Percolation (mm/d)
0
30
Table 4.Percolation together with estimated average concentration (�g/l) of PPU and PPU-desamino 1 m b.g.s. atTylstrup.PercolationPPUPPU-desamino(mm/y)Suction cup – S1Suction cup – S2Suction cup – S1 Suction cup – S21.7.04–30.6.05528<0.02<0.02<0.02<0.021.7.05–30.6.062570.01-0.03<0.02<0.02<0.021.7.06–30.6.075290.070.01-0.020.02<0.011.7.07–30.6.085290.040.030.01<0.011.7.08–30.6.096720.020.02<0.01<0.011.7.09–30.6.104760.010.01<0.01<0.01
When evaluating these results it should be noted that precipitation following theapplication of rimsulfuron (applied on 3 June 2004) amounted to 68 mm in May 2004(20% higher than normal) and 51 mm in June 2004 (21% lower than normal).Precipitation and percolation following the application at Tylstrup were thus muchlower than at Jyndevad in 2003 where rimsulfuron was also applied. Finally, it shouldbe noted that the concentration of PPU is likely to be underestimated by 28-47%.Results from the field-spiked samples revealed that PPU is degraded slightly duringanalysis (see Rosenbomet al.,2010b; section 7.2.2.). Thus, the observed PPU-desaminoprobably derives from degradation in the sample during analysis rather than fromdegradation occurring in the soil. As a consequence, the concentration of PPU is likelyto be underestimated, while that of PPU-desamino is likely to be overestimated.The pesticides applied on winter wheat in 2008 and spring barley in 2009 and theirdegradation products (Table 3) have not been found in any of the analysed watersamples, the exception being tebuconazole detected once in a groundwater sample(0.011 �g/l on 4 April 2008 in M4, 2.5–3.5 m b.g.s.). Moreover, bentazone has beenfound in one sample (10 April 2006, at S1 1 m b.g.s.) originating from the application in2005, indicating that no leaching occurred from the 2009 application.
27
28
3 Pesticide leaching at Jyndevad
3.1
Materials and methods
3.1.1 Site description and monitoring designJyndevad is located in southern Jutland (Figure 1). The test site covers a cultivated areaof 2.4 ha (135 x 184 m) and is practically flat. A windbreak borders the eastern side ofthe test site. The area has a shallow groundwater table ranging from 1 to 3 m b.g.s.(Figure 9B) The overall direction of groundwater flow is towards the northwest (Figure8). The soil can be classified as Arenic Eutrudept and Humic Psammentic Dystrudept(Soil Survey Staff, 1999) with coarse sand as the dominant texture class and topsoilcontaining 5% clay and 1.8% total organic carbon (Table 1). The geological descriptionpoints to a rather homogeneous aquifer of meltwater sand, with local occurrences of thinclay and silt beds. A brief description of the sampling procedure is provided inAppendix 2. The monitoring design and test site are described in detail in Lindhardtetal.(2001) and the analysis methods in Kjæret al.(2002).3.1.2 Agricultural managementManagement practice during the 2008-2009 growing seasons is briefly summarizedbelow and detailed in Appendix 3 (Table A3.2). For information about managementpractice during the previous monitoring periods, see previous monitoring reportsavailable on http://pesticidvarsling.dk/publ_result/index.html.
29
Figure 8.Overview of theJyndevadsite. The innermost white area indicates the cultivated land, while the grey areaindicates the surrounding buffer zone. The positions of the various installations are indicated, as is the direction ofgroundwater flow (by an arrow). Pesticide monitoring is conducted monthly and half-yearly from selected monitoringwells and suctions cups as described in Table A2.1 in Appendix 2.
30
The field was ploughed on 17 March 2009 and the following day sown with springbarley (cv. Simba). The herbicide bifenox was applied on 27 April before the start oftillering. The herbicides bentazone and MCPA were applied two weeks later, at thebeginning of stem elongation, although MCPA was not included in the monitoring.Fungicides were applied around late boot stage on 26 May, using boscalide andepoxiconazole, of which only the latter was monitored. The field was irrigated on threeoccasions: 30 mm on 26 May, at the late boot stage; 27 mm on 5 June at the beginningof heading and finally 27 mm on 29 June, at the beginning of flowering. The crop washarvested on 7 August, yielding 64.0 hkg/ha of grain and 19.5 hkg of straw (85 and100% DM, respectively), grain yield being nearly 30% above the average for the soiltype and year (Plantedirektoratet, 2009).Having been ploughed on 14 April 2010, the field was planted with potatoes (cv. Kuras)on 4 May. Before the potatoes emerged the field was sprayed with the herbicidesaclonifen and rimsulfuron on 27 May. Rimsulfuron was applied again on 8 June. Thefungicide cyazofamid was used five times between 28 June and 9 August , whereasazoxystrobin was applied on 6 July and a combination of mancozeb and metalaxyl on25 July. Aphids were sprayed once using lambda-cyhalothrin on 16 July. The field wasirrigated three times with 25, 25, and 30 mm on 24 June, 30 June and 8 July,respectively. Neither mancozeb, azoxystrobin nor lambda-cyhalothrin was included inthe monitoring. The potatoes were harvested on 19 October yielding 450 hkg/ha with26.8% DM (120.6 hkg/ha at 100% DM), yields being below the average for the soil typeand year (Plantedirektoratet, 2010).3.1.3 Model setup and calibrationThe numerical model MACRO (version 5.1, Larsboet al.,2005) was applied to theJyndevad site covering the soil profile to a depth of 5 m b.g.s., always including thegroundwater table. The model was used to simulate water flow and bromide transport inthe unsaturated zone during the full monitoring period July 1999–June 2010 and toestablish an annual water balance.Compared with the setup in Rosenbomet al.(2010b), a year of validation was added tothe MACRO-setup for the Jyndevad site. The setup was hereby calibrated for themonitoring period May 1999-June 2004 and validated for the monitoring period July2004-June 2010. For this purpose, the following time series have been used: thegroundwater table measured in the piezometers located in the buffer zone, soil watercontent measured at three different depths (25, 60, and 110 cm b.g.s.) from the twoprofiles S1 and S2 (location indicated at Figure 8), and the bromide concentrationmeasured in the suction cups located 1 and 2 m b.g.s (Figure 11). Data acquisition,model setup as well as results related to simulated bromide transport are described inBarleboet al.(2007).
31
Figure 9.Soil water dynamics atJyndevad:Measured precipitation, irrigation and simulated percolation 1 m b.g.s.(A), simulated and measured groundwater level (B), and simulated and measured soil water saturation (SW sat.) atthree different soil depths (C, D and E). The measured data in B derive from piezometers located in the buffer zone.The measured data in C, D and E derive from TDR probes installed at S1 and S2 (Figure 8). The broken vertical lineindicates the beginning of the validation period (July 2004-June 2010).
32
3.2
Results and discussion
3.2.1 Soil water dynamics and water balancesThe model simulations were generally consistent with the observed data, thus indicatinga good model description of the overall soil water dynamics in the unsaturated zone(Figure 9). The dynamics of the simulated groundwater table were well described withMACRO 5.1 (Figure 9B). For the recent hydraulic year, no measurements of the watersaturation were obtained during the following two periods: 1 June – 25 August 2009(given a breakdown in the TDR measuring system) and 7 February – 6 March 2010(given a sensor error). However, as noted earlier in Rosenbomet al.(2010b), the modelstill had some difficulty in capturing the degree of soil water saturation 1.1 m b.g.s.(Figure 9E) and also the decrease in water saturation observed during summer periods at25 and 60 cm b.g.s.The resulting water balance for Jyndevad for the 11 monitoring periods is shown inTable 5. Compared with the previous ten years, the latest hydraulic year July 2009-June2010 was characterised by having medium precipitation, simulated actualevapotranspiration and irrigation values. Precipitation in the latest hydraulic year wascharacterised by November being very wet, and January to June being very dry(Appendix 4). Periods without continuous percolation 1 m b.g.s. were thereforesimulated in the spring of 2010.
Table 5.Annual water balance forJyndevad(mm/yr). Precipitation is corrected to the soil surface according to themethod of Allerup and Madsen (1979).NormalActualGroundwater1)PrecipitationPrecipitationIrrigationEvapotranspirationRecharge2)1.7.99–30.6.009951073295006021.7.00–30.6.0199581004613491.7.01–30.6.029951204815457401.7.02–30.6.03995991514156271.7.03–30.6.04995937274325311.7.04–30.6.059951218875787271.7.05–30.6.069958571174904841.7.06–30.6.0799513041145718471.7.07–30.6.0899510231966136051.7.08–30.6.0999510481145476151.7.09–30.6.109951034805165991)2)
Normal values based on time series for 1961–1990.Groundwater recharge is calculated as precipitation + irrigation - actual evapotranspiration.
33
12Suction cups - S1Bromide (mg/l)
9
1 m b.g.s.630May-99May-00May-01May-02May-03May-04May-05May-06May-07May-08
2 m b.g.s.
May-09
12Bromide (mg/l)
Suction cups - S2
91 m b.g.s.630May-99May-00May-01May-02May-03May-04May-05May-06May-07May-08May-09May-10
2 m b.g.s.
Figure 10.Bromide concentration in the unsaturated zone atJyndevad.The measured data derive from suction cupsinstalled 1 m b.g.s. (upper)and 2 m b.g.s. (lower)at locations S1 and S2 (Figure 8). The green vertical lines indicatethe dates of bromide applications.
3.2.2 Bromide leachingBromide has now been applied twice at Jyndevad. The bromide concentrationsmeasured until April 2003 (Figure 10 and Figure 11) relate to the bromide applied inautumn 1999, as described further in Kjæret al.(2003). Leaching of the bromideapplied in March 2003 is evaluated in Barleboet al.(2007).
34
May-10
Bromide (mg/l)
Bromide (mg/l)
Bromide (mg/l)
Bromide (mg/l)
Bromide (mg/l)
0360369
3
06
Bromide (mg/l) Bromide (mg/l)May-May-9999
0
3
6
0
3
6
9
0
3
6
9
0
3
6
9
May-99
May-99
May-99
May-99M2M1
M6
M7M4
May-00May-00May-01May-02May-03May-04May-05May-06May-07May-08May-09May-10May-05May-06May-07May-08May-09May-10May-04May-03May-02May-01May-01
May-00May-00
M5May-00
M3
May-00May-01May-02May-03May-04May-053-4 m b.g.s.
May-01May-02
May-01
1-2 m b.g.s.
May-02May-03
May-02
May-03May-04
May-03
2-3 m b.g.s.
May-04May-05
May-04
Figure 11.Bromide concentration in the groundwater atJyndevad.The data derive from monitoring wells M1–M7.Monitoring at well M6 was suspended September 2008 (Appendix 2). Screen depth is indicated in m b.g.s. The greenvertical lines indicate the dates of bromide applications.
35
May-05May-06
May-05
May-06May-07
May-06
May-06May-07May-08May-09May-10
May-07May-08
May-07
4-5 m b.g.s.
May-08May-09
May-08
May-09May-10
May-09
May-10
May-10
May
Aug
Nov
0Precipitation (mm/d)
Mar
Dec
Apr
Sep
Feb
Oct
Jun
Jan
Jul
30202008/20091510503025202009/2010151050Precipitation & irrigationEpoxiconazole (2009)Bifenox (2009)Simulated percolationBentazone (2009)
20304050600
Precipitation (mm/d)
102030405060
Figure 12.Application of pesticides included in the monitoring programme, precipitation and irrigation (primaryaxis) together with simulated percolation 1 m b.g.s. (secondary axis) atJyndevadin 2008/2009 (upper) and2009/2010 (lower).
3.2.3 Pesticide leachingMonitoring at Jyndevad began in September 1999 and presently encompasses severalpesticides and their degradation products, as indicated in Table 6. Pesticide applicationduring the two most recent growing seasons is shown together with precipitation andsimulated precipitation in Figure 12. It should be noted that precipitation is corrected tothe soil surface according to Allerup and Madsen (1979), whereas percolation (1 mb.g.s.) refers to accumulated percolation as simulated with the MACRO model. Itshould also be noted that as tribenuron-methyl (applied here as Express), pyridate(applied here as Lido) and rimsulfuron (applied here as Titus) degrade rapidly. Theleaching risk is therefore associated with their respective degradation products:triazinamin-methyl, PHCP, PPU, and PPU-desamino rather than the parent compounds.For the same reasons the degradation products and not the parent compounds aremonitored in PLAP (Table 6). The product Basagran M75 contains two activesubstances, bentazone and MCPA, but only bentazone is monitored. Pesticides appliedlater than April 2010 are not evaluated in this report and hence not included in Table 6and Figure 12.
36
Percolation (mm/d)
Percolation (mm/d)
10
25
Table 6.Pesticides analysed atJyndevadwith the product used shown in parentheses. Degradation products are initalics. Precipitation (prec.) and percolation (perc.) are accumulated from date of first application until end ofmonitoring. 1stmonth perc. refers to accumulated percolation within the first month after application. Cmeanrefers toaverage leachate concentration 1 m b.g.s the first year after application (See Appendix 2 for calculation method).Crop and analysed pesticidesApplication End ofPrec.Perc.1stmonthCmeanDateMonitoring (mm) (mm)perc. (mm) (�g/l)Winter rye 2000Glyphosate (Roundup 2000)Sep 99Apr 0227591607139<0.01-AMPA<0.01Triazinamin-methyl1)(Express)Nov 99Apr 022534145186<0.02Propiconazole (Tilt Top)Apr 00Jul 02230110613<0.01Fenpropimorph (Tilt Top)Apr 00Apr 02201510293<0.01-fenpropimorphic acid<0.01Maize 2001Terbuthylazine (Lido 410 SC)May 01Apr 04311818094<0.01-desethyl-terbuthylazineMay 01Apr 07674238264<0.01–0.02PHCP2)(Lido 410 SC)May 01Jul 03241313664<0.02Potatoes 2002-PPU(Titus)3)May 02Jul 10†93895126110.064)–0.13- PPU-desamino(Titus)3)Jul 10†93895126110.01–0.03Spring barley 2003MCPA (Metaxon)Jun 03Jul 05234012330<0.01- 4-chlor,2-methylphenol<0.01Dimethoate (Perfekthion 500 S)Jun 03Jul 05227812321<0.01Pea 2004Bentazone (Basagran 480)May 04Jul 073888204440.02 – 0.13- AIBA<0.01Pendimethalin (Stomp SC)May 04Apr 07355719964<0.01Pirimicarb (Pirimor G)Jun 04Apr 073493199327<0.01-Pirimicarb-desmethyl<0.01-Pirimicarb-desmethyl-<0.02formamido- fluazifop-P(free acid)5)Jun 04Jul 062395123327<0.01(Fusilade X-tra)Winter wheat 2005Ioxynil (Oxitril CM)Oct 04Apr 072955179181<0.01Bromoxynil (Oxitril CM)Oct 04Apr 072955179181<0.01Amidosulfuron (Gratil 75 WG)Apr 05Jul 07107051533<0.01Fluroxypyr (Starane 180 S)May 05Jul 072683136037<0.02Azoxystrobin (Amistar)May 05Apr 072274128349<0.01- CyPM<0.02Spring barley 2006Florasulam (Primus)May 06Jul 082779148734<0.01- florasulam-desmethyl<0.03Epoxiconazole (Opus)Jun 06Dec 094698259231<0.01Triticale 2007Mesosulfuron-methyl(Atlantis WG)Oct 06Dec 094177241873<0.01-mesosulfuron<0.01Chlormequat (Cycocel 750)Apr 07Jul 0815486891<0.01Epoxiconazole (Opus)May 07Dec 09346518156<0.01Winter wheat 2008Picolinafen (Pico 750 WG)Oct 07Mar 102934168555<0.01- CL153815<0.01Tebuconazole (Folicur EC 250)Dec 07Mar 102807162697<0.01Spring barley 2009Bifenox (Fox 480 SC)Apr 09Jul 10†13766473<0.02- bifenox acid<0.05- nitrofen<0.01Bentazone (Basagran M75)May 09Jul 10†1328646140.06Epoxiconazole (Bell)May 09Dec 0997251843<0.011)
Systematic chemical nomenclature for the analysed pesticides is given in Appendix 1.Degradation product of tribenuron-methyl. The parent compound degrades too rapidly to be detected by monitoring.2)Degradation product of pyridate. The parent compound degrades too rapidly to be detected by monitoring.3)Degradation product of rimsulfuron. The parent compound degrades too rapidly to be detected by monitoring.4)Leaching increased the second year after application (see Figure 13).5)Degradation product of fluazifop-P-butyl. The parent compound degrades too rapidly to be detected by monitoring.† Monitoring will continue for an additional year. The values for prec. and perc. are accumulated up to July 2009.
37
Precipitation & irrigationMar-04Mar-05Mar-06Apr-02Apr-03
RimSMar-07
Simulated percolationMar-08Mar-09Mar-10
Precipitation (mm/d)
1020304050600.3A
2520151050Suction cups - S11 m b.g.s.
B
Pesticide (�g/l)
0.2
0.1
0.00.3Suction cups - S21 m b.g.s.
C
Pesticide (�g/l)
0.2
0.1
0.0Apr-02Apr-03Mar-04Mar-05Mar-06Mar-07Mar-08Mar-09Mar-10
PPU
PPU-desamido
Figure 13.Precipitation, irrigation and simulated percolation 1 m b.g.s. (A) together with measured concentrations ofPPUandPPU-desamino (�g/l)in suction cups installed 1 m b.g.s. at location S1 (B) and S2 (C) atJyndevad.Thegreen vertical line indicates the date of pesticide application. Open symbols indicate concentrations below the limit ofdetection (0.02 �g/l prior to July 2006 and 0.01 �g/l thereafter).
The current report focuses on the pesticides applied from 2008 and onwards, whileleaching risk of pesticides applied before 2008 has been evaluated in previousmonitoring reports (see http://pesticidvarsling.dk/publ_result/index.html). Since PPUand PPU-desamino (degradation products of rimsulfuron applied in 2003) were stillincluded in the current monitoring period, the results of these applications are, however,summarised below and in Rosenbomet al.(2010a). For a detailed description of theleaching pattern, including primary data and climatic conditions characterising themonitoring periods, see Kjæret al.(2005c).
38
Percolation (mm/d)
0
30
Precipitation & irrigationMar-04Mar-05Apr-02Apr-03
Rimsulfuron app.Mar-06Mar-07
Simulated percolationMar-08Mar-09Mar-10
Precipitation (mm/d)
1020304050600.2A
2520151050PPUmonitoring wellsB
Pesticide (�g/l)
0.1
0.0
Pesticide (�g/l)
0.2PPU-desaminomonitoring wells0.1C
0.0
Apr-02
Apr-03
Mar-04
Mar-05
Mar-06
Mar-07
Mar-08
Mar-09
M1 (0.6-1.6)M2 (1.0-2.0)M4 (1.4-2.4)M7 (4.6-5.6)
M1 (1.6-2.6)M2 (1.9-2.9)M4 (2.4-3.4)M7 (1.6-2.6)
M1 (2.6-3.6)M2 (2.9-3.9)M4 (3.3-4.3)M7 (2.6-3.6)
M1 (3.6-4.6)M2 (4.0-5.0)M4 (4.4-5.4)M7 (3.6-4.6)
Figure 14.Precipitation, irrigation and simulated percolation 1 m b.g.s. (A) together with measured concentrations(�g/l) in downstream (M1, M2, M4) and upstream monitoring wells (M7) ofPPU(B) andPPU-desamino(C) atJyndevad.The numbers in parentheses indicate the depths of the analysed screens. The green vertical line indicatesthe date of pesticide application. Open symbols indicate concentrations below the limit of detection (0.02 �g/l prior toJuly 2006 and 0.01 �g/l thereafter).
Two degradation products of rimsulfuron, PPU and PPU-desamino, were detected at 1m depth in the suction cups at S1 and S2 (Figure 13). Both compounds werecharacterised by continuous leaching over a long period of time. Although theconcentration decreased during the last monitoring year, PPU could still be found in lowconcentrations towards the end of 2009/2010, i.e. eight years after application. Averageyearly concentrations of PPU reaching 0.1 �g/l were seen as long as three years afterapplication (Figure 13 and Table 7). With an overall travel time of about four years,PPU also reached the downstream monitoring screens (Figure 14). The most recentdetection of PPU in monitoring screens of M1 (sampled monthly) was 0.011 �g/l on 3February 2010. In M2 (sampled half-yearly) the most recent detections were from 30September 2009 (0.022- 0.046 �g/l). PPU showed up in M4 (sampled monthly) for thefirst time in September 2006. From then and until April 2010 PPU has been detected in119 of a total of 129 samples, concentrations ranging between 0.011 and 0.049 �g/l. InM7, PPU was still present on 17 March 2010 at 0.026 �g/l (Figure 9 and Figure 15).
39
Mar-10
Percolation (mm/d)
0
30
Table 7.Percolation together with estimated average concentrations (�g/l) of PPU and PPU-desamino 1 m b.g.s. atJyndevad.Leached mass refers to the total mass (% of applied rimsulfuron) leached during the monitoring period1.7.02–30.6.10.PercolationPPUPPU-desamino(mm/y)Suction cup – S1Suction cup – S2Suction cup – S1Suction cup – S21.7.02–30.6.037060.130.060.03-0.040.01-0.031.7.03–30.6.044680.120.100.040.041.7.04–30.6.057590.100.140.03-0.040.051.7.05–30.6.064650.070.090.01-0.02<0.021.7.06–30.6.078150.050.080.010.021.7.07–30.6.086430.020.040.01<0.011.7.08–30.6.09623<0.010.02<0.01<0.011.7.09–30.6.10619<0.010.01<0.01<0.011)
Expressed as rimsulfuron equivalent
The tracer test suggested that water sampled in M7 had not infiltrated at the PLAP site,but originated from the upstream neighbouring fields, where rimsulfuron had also beenapplied (Kjæret al.,2007).Furthermore, PPU-desamino was detected in monitoring wells, although the number ofdetections and concentration levels were lower than those of PPU-desamino (Figure14C and Table A5.2 in Appendix 5). Finally, it should be noted that the concentration ofPPU is likely to be underestimated by up to 22-44% due to stability problems, asdescribed in Rosenbomet al.2010a and section 7.2.2.Four pesticides (tebuconazole, chlormequat, epoxiconazole and picolinafen, which candegrade to CL153815) were applied during the 2007/08 growing season. Picolinafenwas detected in a monitoring well just once, at a concentration of 0.015 �g/l, whereas itsmetabolite CL153815 was not found. Tebuconazole was detected once at 0.014 �g/l insuction cups. Juhleret al.(2010) conducted a detailed analysis on the fate and transportof chlormequat at the site. This analysis was financially supported by CopenhagenEnergy (Københavns Energi A/S). Chlormequat was not detected at all andepoxiconazole just once. None of the detections exceeded 0.1 �g/l (Table A5.2,Appendix 5).The herbicides bifenox and bentazone were used in the spring barley sown in 2009.Bifenox was found twice in suctions cups, in concentrations of 0.034 and 0.036 �g/l,four to six months after the application as well as in two monitoring wells five monthsafter application, in concentrations of 0.05 and 0.033 �g/l (Table A5.2). The metabolitebifenox acid was found once, 0.1 �g/l, in a monitoring well four months afterapplication. Bentazone was absent in all the samples from the monitoring wells (Table20). It was, however, found frequently in samples from suction cups (Figure 15B andTable 18), reaching a maximum of 0.71 �g/l. None of the substances were leached inyearly average concentrations exceeding 0.1 �g/l (Table 6).
40
Precipitation & irrigationMay-09Nov-09Apr-09Sep-09Jul-09
Simulated percolationMay-10Mar-10Jan-10
Precipitation (mm/d)
1020304050600.8
25201510A50
BPesticide (�g/l)0.60.40.20.0Nov-09Sep-09May-09May-10Apr-09Mar-10Jan-10Jul-09
S1
S2
Figure 15.Precipitation, irrigation and simulated percolation 1 m b.g.s. (A) together with measured concentrations ofbentazone in suction cups installed 1 m b.g.s. at location S and S2 (B) atJyndevad.The green vertical line indicatesthe date of pesticide application. Open symbols indicate concentrations below the limit of detection. Bentazone hasnot been detected in any water samples from the groundwater monitoring wells.
41
Percolation (mm/d)
0
30
42
4 Pesticide leaching at Silstrup
4.1
Materials and methods
4.1.1 Site description and monitoring designThe test field at Silstrup is located south of Thisted in north-western Jutland (Figure 1).The cultivated area is 1.69 ha (91 x 185 m) and slopes gently 1–2� to the north (Figure15). Based on two profiles excavated in the buffer zone bordering the field the soil wasclassified as Alfic Argiudoll and Typic Hapludoll (Soil Survey Staff, 1999). The topsoilcontent of clay in the two profiles was 18 and 26%, and the organic carbon content was3.4 and 2.8%, respectively (Table 1). The geological description showed ratherhomogeneous clay till rich in chalk and chert, containing 20–35% clay, 20–40% silt,and 20–40% sand. In some intervals the till was sandier, containing only 12–14% clay.Moreover, thin lenses of silt and sand were found in some of the wells. The gravelcontent was approx. 5%, but could be as high as 20%. A brief description of thesampling procedure is provided in Appendix 2. The monitoring design and test site aredescribed in detail in Lindhardtet al.(2001) and the analysis methods in Kjæret al.(2002).4.1.2 Agricultural managementManagement practice during the 2008-2009 growing seasons is briefly summarizedbelow and detailed in Appendix 3 (Table A3.3).. For information about managementpractice during the previous monitoring periods, see previous reports available onhttp://pesticidvarsling.dk/publ_result/index.html.Having been harrowed, levelled and rolled between 21 April and 5 May 2008 the fieldwas sown with fodder beat (cv. Kyros) on 7 May, which emerged on 15 May. A firstspraying of weeds was done on 22 May when the first leaf was visible (pinhead-size)and the cotyledons horizontally unfurled, using triflusulfuron, metamitron, andphenmedipham. A second spraying of weeds took place on 30 May, the crop havingthree leaves unfurled, using triflusulfuron, metamitron, ethofumesate, andphenmedipham.
43
Figure 16.Overview of theSilstrupsite. The innermost white area indicates the cultivated land, while the grey areaindicates the surrounding buffer zone. The positions of the various installations are indicated, as is the direction ofgroundwater flow (by an arrow). Pesticide monitoring is conducted weekly from the drainage system (during periodof continuous drainage runoff) and monthly and half-yearly from selected groundwater monitoring wells as describedin Table A2.1 in Appendix 2.
44
A third spraying of weeds took place on 17 June , at the stage of five unfurled leaves,using triflusulfuron, metamitron, ethofumesate, and phenmedipham. All of theseherbicides except phenmedipham were included in the monitoring programme. On 26June pests were treated with pirimicarb (not monitored) at the stage of six leaves. On 1July weeds were sprayed a fourth time using fluazifop-P-butyl, at seven leaves. Whenthe crop had eight unfurled leaves on 4 July a fifth and final treatment of weeds wasdone using triflusulfuron, metamitron, and phenmedipham. A last spraying withpirimicarb (not monitored) against pests took place on 9 July where the crop covered20% of the area. Beets were harvested on 27 October, yielding 17.3 t/ha of 100% DM.All beet tops (5.2 t/ha) were shredded and ploughed into the soil on 15 December.Having been harrowed twice on 30 March 2009, pig slurry was injected and potassiumbromide applied as a tracer on 2 April. Sowing of spring barley (cv. Keops), undersownwith red fescue (cv. Jasperina), took place on 11 April 2009. The herbicide bentazonewas sprayed on 19 May, when the barley had four detectable tillers. The fungicideazoxystrobin was applied on 24 June, but not included in the monitoring. On 16 July thespring barley was harvested as wholecrop, yielding 94.6 hkg/ha (100% DM). The redfescue was later sprayed with the herbicides iodosulfuron on 24 August, four tillersdetectable, and with bifenox on 9 September, five tillers detectable. On 2 May 2010weeds were sprayed with fluazifop-p-butyl and on 5 May with iodosulfuron and MCPA,the latter two were, however, not included in the monitoring. Harvest of grass seedstook place on 20 July, yielding 16.5 hkg/ha of seeds (87% DM). An amount of 69.3hkg/ha of straw (100% DM) was burned in the field on 21 July 2010.4.1.3 Model setup and calibrationCompared with the setup in Rosenbomet al.(2010b), a year of validation was added tothe MACRO setup for the Silstrup site. The setup was hereby calibrated for themonitoring period May 1999-June 2004 and validated for the monitoring period July2004-June 2010. For this purpose, the following time series have been used: theobserved groundwater table measured in the piezometers located in the buffer zone, soilwater content measured at three depths (25, 60, and 110 cm b.g.s.) from the two profilesS1 and S2 (Figure 15), and the measured drainage flow. Data acquisition, model setupand results related to simulated bromide transport are described in Barleboet al.(2007).Given impounding of water in the drainage water monitoring well, estimates for themeasured drainage on 11 December 2006, 13-14 December 2006, and 28 February 2007were based on expert judgment. Additionally, TDR-measurements at 25 cm b.g.s. in theperiod 15 December 2009 – 20 March 2010 were discarded given freezing soils (soiltemperatures at or below zero degrees Celsius). The soil water content is measured withTDR based on Topp calibration (Toppet al.,1980), which will underestimate the totalsoil water content at the soil water freezing point as the permittivity of frozen water ismuch less than that of liquid water (Flerchingeret al.,2006).
45
4.2
Results and discussion
4.2.1 Soil water dynamics and water balancesThe model simulations were largely consistent with the observed data, thus indicating areasonable model description of the overall soil water dynamics in the unsaturated zone(Figure 17). As in Rosenbomet al.(2010b), the simulated groundwater table of thishydraulic year was validated against the much more fluctuating groundwater tablemeasured in piezometer P3, which yielded the best description of measured drainage(Figure 17B and 17C). The first drainage flow period of the past year was well capturedby the model, whereas the magnitude of the second drainage flow period was notcaptured (Figure 17C). The last period can be characterised by frozen soil andprecipitation in the form of snow – a situation, which MACRO has difficulties indescribing. Additionally, drainage flow (q) is calculated by means of continuousmeasurements of the water height (h) at a V-notch in the drainage well and a q/hrelationship. At events with extreme water flow it may happen that the discharge pipehas inadequate capacity to discharge the water, so that water will rise above the V-notchplate in the drainage well. This was the case during the snowmelt occurring on 12March 2010, why adequate water sampling was not possible. At these events the q/hrelationship is not valid, and the drainage flow is estimated at a water height (h)corresponding to the maximum height (h) of the V-notch plate, which could haveresulted in an overestimation of the measured drainage flow. As in the previousmonitoring periods, the overall trends in soil water content were described reasonablywell (Figure 17D, 17E, and 17F), although the model still tended to describe the subsoilas being much drier during the summer period than measured by the deeper TDR probes(Figure 17E and 17F).
46
Figure 17.Soil water dynamics atSilstrup:Measured precipitation and simulated percolation 1 m b.g.s. (A),simulated and measured groundwater level GWT (B), simulated and measured drainage flow (C), and simulated andmeasured soil water saturation (SW sat.) at three different soil depths (D, E, and F). The measured data in B derivefrom piezometers located in the buffer zone. The measured data in D, E, and F derive from TDR probes installed atS1 and S2 (Figure 16). The broken vertical line indicates the beginning of the validation period (July 2004-June2010).
47
Table 8.Annual water balance forSilstrup(mm/year). Precipitation is corrected to the soil surface according to themethod of Allerup and Madsen (1979).NormalActualMeasuredSimulated Groundwaterprecipitation2)Precipitation evapotranspirationdrainagedrainagerecharge3)1.7.99–30.6.001)9761175457–4432754)1.7.00–30.6.019769094132172322791.7.01–30.6.0297610344702272793381.7.02–30.6.0397687953781742611.7.03–30.6.0497676051714897941.7.04–30.6.059769134911551582671.7.05–30.6.06976808506101952011.7.06–30.6.0797611505393613072491.7.07–30.6.089768774342001842421.7.08–30.6.099769855271612602961.7.09–30.6.109768353982032222341)The monitoring started in April 2000.2)Normal values based on time series for 1961–1990 corrected to soil surface.3)Groundwater recharge calculated as precipitation - actual evapotranspiration - measured drainage.4)Where drainage flow measurements were lacking, simulated drainage flow was used to calculate groundwaterrecharge.
The resulting water balance for Silstrup for the entire monitoring period is shown inTable 8. Compared with the previous 11 years, the recent hydraulic year July 2009-June2010 was characterised by having the third lowest precipitation, the lowest simulatedactual evapotranspiration, and the fourth-highest measured drainage. Precipitation ofthis year was characterised by having the wettest month ever monitored at Silstrup inNovember with more than 300 mm, and August, September, March, April and Junebeing very dry (Appendix 4). Due to this precipitation pattern, the simulated percolationpattern of the year July 2009-June 2010 was not represented by continuous percolation(Figure 17A). The climatic setting of this year gave rise to short periods with thegroundwater table above the drainage level, causing the fourth-largest measureddrainage since monitoring started in July 2000 (Figure 17B and 17C).
48
3Bromide (mg/l)
Suction cups - S12103
1 m b.g.s.2 m b.g.s.
A
Suction cups - S2Bromide (mg/l)
1 m b.g.s.2 m b.g.s.
B
2103
Bromide (mg/l)
Drains
2103
Bromide, time-proportional samplingBromide, flow-proportional samplingDrainage runoff
20100
Horizontal monitoring wells - 3.5 m b.g.s.Bromide (mg/l)
2
H1.2H2.2
H1.1H2.1
H1.3H2.3D
1
0Apr-00Apr-01Apr-02Apr-03Apr-04Apr-05Apr-06Apr-07Apr-08Apr-09Apr-10
Figure 18.Bromide concentration atSilstrup.A and B refer to suction cups located at S1 and S2 (see Figure 16).The bromide concentration is also shown for drainage runoff (C) and the horizontal monitoring wells H1 and H2 (D).In March 2009, bromide measurements in the suction cups were suspended (Appendix 2). The green vertical linesindicate the dates of bromide applications.
4.2.2 Bromide leachingThe bromide concentrations shown in Figure 18 and Figure 19 relate to the bromideapplied in May 2000, as described in previous reports (Kjæret al.2003 and Kjæret al.2004) and further evaluated in Barleboet al.(2007). In Marts 2009, bromidemeasurements in the suction cups and monitoring wells M6 and M11 were suspended.In April 2009, 31.5 kg/ha potassium bromide was applied for the second time.
49
Drainage runoff (mm/d)
C
30
1.5-2.5 m2Bromide (mg/l)
3.5-4.5 m
4.5-5.5 mM5
1
02Bromide (mg/l)
M91
0
Apr-00
Mar-01
Mar-02
Mar-03
Mar-04
Mar-05
Mar-06
Feb-07
Feb-08
Feb-09
2Bromide (mg/l)
M10
1
0Apr-00Mar-01Mar-02Mar-03Mar-04Mar-05Feb-07Feb-08Feb-09
2Bromide (mg/l)
Mar-06
M12
1
0Apr-00Mar-01Mar-02Mar-03Mar-04Mar-05Feb-07Feb-08Feb-09Mar-06Feb-10
Figure 19.Bromide concentration atSilstrup.The data derive from the vertical monitoring wells (M5–M12). InSeptember 2008, monitoring wells M6 and M11 were suspended (Appendix 2). Screen depth is indicated in m b.g.s.The green vertical lines indicate the date of bromide applications.
4.2.3 Pesticide leachingMonitoring at Silstrup began in May 2000 and presently encompasses several pesticidesand their degradation products, Table 9. Pesticide application during the two mostrecent growing seasons is shown together with precipitation and simulated percolationin Figure 19. It should be noted that precipitation in Table 9 is corrected to soil surfaceaccording to Allerup and Madsen (1979), whereas percolation (1 m b.g.s.) refers toaccumulated percolation as simulated with the MACRO model. Moreover, pesticidesapplied later than April 2010 are not evaluated in this report and hence not included inTable 9.
50
Feb-10
Feb-10
May
Aug
Nov
0
Mar
Dec
Apr
Sep
Feb
Oct
Jun
Jan
Jul
302015105030202009/2010151050PrecipitationEthofumesat (2008)Bentazone (2009)Potasium bromide (2009)Bifenox (2009)Triflusulfuron-methyl & metamitron (2008)Fluazipop-P-butyl (2008)Azoxystrobin (2009)Iodosulfuron (2009)Simulated percolation
Precipitation (mm/d)
20304050600
2008/2009
Precipitation (mm/d)
2030405060
Figure 20.Application of pesticides included in the monitoring programme, precipitation, and irrigation (primaryaxis) and simulated percolation 1 m b.g.s. (secondary axis) atSilstrupin 2008/2009 (upper) and 2009/2010 (lower).
It should also be noted that as tribenuronmethyl (applied here as Express), pyridate(applied here as Lido), and fluazifop-P-butyl (Fusilade Max) degrade rapidly, theleaching risk is associated with their respective degradation products: triazinamin-methyl, PHCP, fluazifop-P, and TFMP rather than the parent products. For the samereasons the degradation products and not the parent compounds are monitored in thePLAP (Table 9).
51
Percolation (mm/d)
10
25
Percolation (mm/d)
10
25
Table 9.Pesticides analysed atSilstrupwith the product used shown in parentheses. Degradation products are initalics. Precipitation (prec.) and percolation (perc.) are accumulated from date of first application until end ofmonitoring. 1stmonth perc. refers to accumulated percolation within the first month after application. Cmeanrefers toaverage leachate concentration in the drainage water within the first drainage season after application (See Appendix2 for calculation methods).Crop and analysed pesticidesApplicationEnd ofPrec.Perc.1stmonthCmeandatemonitoring (mm)(mm) perc. (mm)(�g/l)Fodder beet 2000Metamitron (Goltix WG)-metamitron-desaminoEthofumesate (Betanal Optima)Desmedipham (Betanal Optima)-EHPCPhenmedipham (Betanal Optima)-MHPC- 3-aminophenolFluazifop-P-butyl (Fusilade X-tra)- fluazifop (free acid)Pirimicarb (Pirimor G)- pirimicarb-desmethyl- pirimicarb-desmethyl-formamidoSpring barley 2001Triazinamin-methyl1)(Express)Flamprop-M-isopropyl (Barnon Plus 3)- flamprop (free acid)Propiconazole (Tilt Top)Fenpropimorph (Tilt Top)- fenpropimorphic acidDimethoate (Perfekthion 500 S)Maize 2002Glyphosate (Roundup Bio)- AMPAPHCP2)(Lido 410 SC)Terbuthylazine (Lido 410 SC)- desethyl-terbuthylazine- 2- hydroxy-terbuthylazine- 2-hydroxy-desethyl-terbuthylazine- desisopropyl-atrazinePeas 2003Bentazone (Basagran 480)-AIBAPendimethalin (Storm SC)Glyphosate (Roundup Bio)-AMBAWinter wheat 2004Prosulfocarb (Boxer EC)MCPA (Metaxon)- 4-chlor,2-methylphenolAzoxystrobin (Amistar)- CyPMPirimicarb (Pirimor G)- Pirimicarb-desmethyl- Pirimicarb-desmethyl-formamido1)2)
May 00May 00May 00May 00
Apr 03Apr 03Apr 03Apr 03
2634263426342634
1328132813281328
53535353
Jun 00Jul 00
Jul 02Jul 07
19536452
10192825
51
0.050.060.03<0.01<0.02<0.01<0.02<0.02<0.01<0.02<0.01<0.01<0.02<0.02<0.01<0.01<0.01<0.01<0.010.020.130.060.060.070.153)3)3)
May 01Jun 01Jun 01Jun 01Jul 01Oct 01May 02May 02
Jul 03Jul 03Jul 03Jul 03Jul 03Apr 06Jul 04Apr 06Apr 05Apr 05Apr 05Apr 05Jul 06Apr 06Apr 06
19411928192819281882380217643320
95194494494493716947381327
1033334466
May 03May 03Sep 03
263426342207
10551055971
44440
0.26<0.01<0.01<0.010.020.01<0.01<0.010.010.09<0.01<0.01<0.02
Oct 03May 04Jun 04Jul 04
Apr 06Jul 06Jul 06Jul 07Jul 07
21251797178129312818
97471070612021205
374000
Degradation product of tribenuron-methyl. The parent compound degrades too rapidly to be detected by monitoring.Degradation product of pyridate. The parent compound degrades too rapidly to be detected by monitoring.3)Average leachate concentration within the first drainage season after application could not be calculated, as monitoringstarted January 2003 (7 mount after application). See Kjær et al.(2007) for further information.
The current report focuses on the pesticides applied from 2008 and onwards, while theleaching risk of pesticides applied before 2008 has been evaluated in previousmonitoring reports (see http://pesticidvarsling.dk/publ_result/index.html).
52
Table 9 continued.Pesticides analysed atSilstrupwith the product used shown in parentheses. Degradationproducts are in italics. Precipitation (prec.) and percolation (perc.) are accumulated from date of first application untilend of monitoring. 1stmonth perc. refers to accumulated percolation within the first month after application. Cmeanrefers to average leachate concentration in the drainage water within the first drainage season after application (SeeAppendix 2 for calculation methods).Crop and analysed pesticidesApplicationEnd ofPrec.Perc. 1stmonthCmeandatemonitoring(mm)(mm) Perc. (mm)(�g/l)Spring barley 2005Fluroxypyr (Starane 180 S)May 05Jul 07201283011<0.02Azoxystrobin (Amistar)Jun 05Jul 06862332100.01- CyPMJun 05Jul 072012828100.02Pirimicarb (Pirimor G)Jul 05Jul 0719338180<0.01- Pirimicarb-desmethyl<0.01- Pirimicarb-desmethyl-formamido<0.01Winter rape 2006Propyzamide (Kerb 500 SC)Nov 05Apr 0823451115750.221)- RH-246440.011)- RH-24580<0.011)<0.011)- RH-24655Clopyralid (Matrigon)Apr 06Apr 0820098598<0.01Winter wheat 2007Pendimethalin (Stomp Pentagon)Sep 06Apr 0816868650<0.04Iodosulfuron-methyl-sodium(Hussar OD)Apr 07Apr 0919408753<0.01<0.01- Metsulfuron-methyl<0.01-TriazinaminChlormequat (Cycocel 750)Epoxiconazole (Opus)Fodder beet 2008Triflusulfuron (Safari)- IN-D8526- IN-E7710- IN-M7222Metamitron (Goliath)- Metamitron-desaminoEthofumesate- Fluazifop-P2)(Fusilade Max)- TFMP2)(Fusilade Max)Spring barley 2009Bentazone (Fighter 480)Azoxystrobin (Amistar)- CyPMIodosulfuron (Hussar OD)- Metsulfuron-methyl-TriazinaminBifenox (Fox 480 SC)- Bifenox acid- Nitrofen1)
Apr 07Jun 07May 08
Jul 08Apr 09Jul 10
109918671894
392873895
304
<0.01<0.01<0.01<0.01<0.01<0.010.010.01<0.01<0.010.22<0.010.010.06<0.01<0.01<0.01<0.012.22<0.01
May 08May 08Jul 08
Jul 10†Jul 10†Jul 10†
189418931820
895893890
4321
May 09Jun 09Aug 09
Jul 10†Jul 10†Jul 10†Jul 10†
929835736
397396401
100
Sep 09
710
402
0
Drainage runoff commenced two weeks prior to the application of propyzamide, and the weighted concentrations refer tothe period from the date of application until 1 July 2007.2)Degradation product of fluazifop-P-butyl. The parent compound degrades too rapidly to be detected by monitoring.† Monitoring will continue for an additional year. The values for prec. and perc. are accumulated up to July 2009.
53
May-08
Nov-08
Nov-09
Apr-09
Apr-10
Sep-08
Feb-09
Sep-09
Jun-09
0Precipitation (mm/d)
Jun-10
Jan-10
Jul-08
7560453015A
816243240
0
1Pesticide (�g/l)
32MetamitronB
0.1
168032
0.011Pesticide (�g/l)
0.1
168032
0.011
Pesticide (�g/l)
Ethofumesate0.1
D
168032
0.011
Pesticide (�g/l)
0.1
1680
0.01
May-08
Nov-09
Nov-08
Apr-09
Pesticide concentration
Drainage runoff
Figure 21.Precipitation and simulated percolation 1 m b.g.s. (A) together with the concentration of metamitron (B),metamitron-desamino (C) Ethofumesate (D) and IN-E7710 (E) in the drainage runoff atSilstrup.The green verticallines indicate the dates of applications. Open symbols indicate values below the detection limit of 0.01 �g/l. Whileethofumesate and IN-E7710 were not detected in any samples from groundwater monitoring, metamitron andmetamitron-desamino have been found occasionally (see text).
54
Apr-10
Jun-09
Sep-09
Sep-08
Feb-09
Jun-10
Jan-10
Jul-08
DR (mm/d)
IN-E7710
E
24
DR(mm/d)
24
DR (mm/d)
Metamitron-desamino
C
24
DR(mm/d)
24
Percolation (mm/d)
Hitherto, there has been no leaching of triflusulfuron, whereas one of its degradationproducts IN-E7710 (Table 9 and Figure 21E) was found on four occasions in drainagewater. The two other degradation products included in the monitoring programme (IN-D8526 and IN-M7222) could not be detected.At Silstrup, the herbicides ethofumesate and metamitron have now been applied both in2000 and 2008 (Table 9). Whereas 345 g/ha of ethofumesate was applied in 2000, only70 g/ha of ethofumesate was applied in 2008 (71 g/ha every 3rdyear being theadmissible dose). The reduced application may be part of the reason why there was onlya single detection following the 2008 application, as compared to the 24 following theapplication in 2000, where the average yearly concentrations reduced from 0.03 to lessthan 0.01 �g/l over the eight-year period. An additional explanation for the reducedleaching could also be that percolation following application was much lower in 2008than in 2000 (see Table 9).The maximum allowed doses of metamitron were not regulated between the 2000 andthe 2008 application remaining at 2,100 g/ha of metamitron. However, in the PLAPonly 1,400 g/ha was applied in 2008. Although both metamitron and its degradationproduct metamitron-desamino were found in drainage (Table 9, Figure 21B and 21C)and groundwater samples (Table A5.3), the number of findings as well as theconcentrations were lower than seen after the application in 2000, and the limit of 0.1�g/l was in no case exceeded.The herbicide triflusulfuron was applied concomitantly with metamitron, and thesubstance as well as three of its metabolites (IN-D8526, IN-M7222 and IN-E7710) wasmonitored. Triflusulfuron and the metabolite IN-D8526 were not found at all, and IN-M7222 only once (Table A5.3). IN-E7710 was detected on four occasions (Figure 21Eand Table 18).Fluazifop-P-butyl, a herbicide used against monocotyledons, in this case couch grass(Agropyrum repens, L.), has been included in the PLAP several times over the past 10years. As fluazifop-P-butyl rapidly degrades, focus has so far been on its degradationproduct fluazifop-P (free acid). Similar to the 2000/2001 growing season at Silstrup(Kjæret al.,2003), this compound, was found in neither drainage water (Figure 22B)nor groundwater (Figure 22D). When applying fluazifop-P-butyl in July 2008 andincluding its degradation product TFMP in the monitoring programme, a differentpicture emerged (Figure 22C and Figure 22E). At the onset of the drainage flow on 11September 2008, a concentration of 0.52 �g/l TFMP was found. Concentrationsremained above 0.1 �g/l throughout the period of drainage runoff. Further, TFMP wasfound in the screens of the vertical monitoring wells M5.1 (1.5 to 2.5 m b.g.s) and M5.2(2.5 to 3.5 m b.g.s.) more than one month prior to the detection in the drainage water, inconcentrations of 0.11 and 0.064 �g/l, respectively (Figure 22C). With the groundwatertable minimum 1.6 m b.g.s., the root zone being relatively dry, and with percolation 1 mb.g.s. in July-August 2008 (Figure 17 and Figure 22A), this indicates pronouncedmacropore transport bypassing the tile drainage system.
55
May-08
Apr-09
Precipitation (mm/d)
Apr-10
Oct-08
Oct-09
Jan-09
Jan-10
Jul-08
Jul-09
010203040501
7560
A
453015032
Pesticide (�g/l)
0.1
168
0.01
1Pesticide (�g/l)
032C
0.1
1680
0.01Pesticide concentrationDrainage runoff
1Pesticide (�g/l)
D
Fluazifop-P (free acid)Monitoring wells
0.1
0.011Pesticide (�g/l)
E0.1
TFMPMonitoring wells
0.01May-08Oct-08Apr-09Oct-09Apr-10Jul-08Jan-09Jul-09Jan-10
M5 (1.5-2.5 m)H1 (3.5 m b.g.s.)
M5 (2.5-3.5 m)H2 (3.5 m b.g.s.)
M5 (3.5-4.5 m)
Figure 22.Precipitation and simulated percolation 1 m b.g.s. (A) together with the concentration of fluazifop-P (freeacid) (B) and TFMP (C) in the drainage runoff, and the concentration of fluazifop-P (free acid) (D) and TFMP (E) inthe groundwater monitoring screens atSilstrup.The green vertical lines indicate the dates of fluazifop-P-butylapplications. Values below the detection limit of 0.01 �g/l are shown as 0.01�g/l (all graphs) and further representedby open symbols in A, B and C.
56
DR(mm/d)
TFMPDrains
24
DR (mm/d)
B
Fluazifop-P (free acid)Drains
24
Percolation (mm/d)
During the summer of 2009 there was no drainage flow. However, at the onset of flowin the autumn of 2009, TFMP was still present (Figure 22C), the last detection being0.023 �g/l on 2 December 2009. Since 18 March 2009 there has been no exceedance ofthe 0.1 �g/l in the drainage water, and since 1 April 2009 in the groundwater. The mostrecent detection of TFMP was 0.03 �g/l on 1 December 2009. The average leachingconcentration in drainage water within the first year of application of fluazifop-p-butyl,amounted to 0.22 �g/l of TFMP (Table 9). Maximum concentration of TFMP in thegroundwater at Silstrup was 0.29 �g/l (Table 20).Bifenox, applied in the spring barley on 9 September 2009, was found only in thesampling on 30 September in five screens of three different monitoring wells (Figure23B); in all but one, the concentrations were less than 0.1 �g/l. In the groundwater,bifenox acid was found in screens from both horizontal and vertical wells (Figure 23E).Four of the five detections from the horizontal wells exceeded 0.1 �g/l, maximum,concentrations being 0.86 �g/l. Concentrations found in the vertical wells were evenhigher, amounting to 3.1 �g/l. The bifenox acid appeared in the groundwater before itwas found in drainage water, in this case seven days earlier.Bentazone applied on 19 May 2009 had also been applied in May 2003. Although theamount of active ingredient was the same in both years, the 2003 application wasfollowed by concentrations that were above 0.1 �g/l in both drainage and groundwater(Kjær et all, 2005), as opposed to the 2009 application where 0.1 �g/l was neverexceeded (Figure 24B, 24E and Table 9). These results may reflect the importance ofdifferent climatic conditions following a spraying.Azoxystrobin, applied on 24 June 2009, as well as it metabolite CyPM were found indrainage water (Figure 24C and 24D). The concentrations of the metabolite weregenerally higher than those of the parent compound. All concentrations but one ofCyPM were below 0.1 �g/l. Average yearly concentrations in drainage water amountedto 0.01 and 0.06 for azoxystrobin and CyPM, respectively (Table 9), which is about thesame as for the two previous applications in 2004 and 2005 (Table 9). Whereas therewere no detections of azoxystrobin in the groundwater, CyPM could be found in bothhorizontal and vertical wells, concentrations ranging between 0.013 and 0.086 �g/l and0.011 and 0.1 �g/l, respectively.When evaluating the leaching occurring during the 2009/2010 drainage season (Figure21–24) it should be noted that the large drainage event that took place during thesnowmelt on 12 March 2010 (28 mm/d) could not be sampled due to technical problemscaused by the extreme intensity of the drainage runoff. Likewise the drainage runoffcould not be measured, and the estimated value for this day is likely to be overestimated(see section 4.2.1 for details).
57
May-10
Aug-09
Nov-09
Mar-10
Dec-09
Apr-10
Sep-09
Feb-10
Oct-09
Precipitation (mm/d)
102030405010
60
A
453015032
Pesticide (�g/l)
10.1
168032
0.0110Pesticide (�g/l)
10.1
1680
0.01
Pesticide concentration10Pesticide (�g/l)
Drainage runoffBifenoxMonitoring wells
D
10.1
0.0110Pesticide (�g/l)
E10.1
Bifenox-acidMonitoring wells
0.01May-10Aug-09Nov-09Oct-09Dec-09Mar-10Apr-10Jul-09Jul-09Sep-09Feb-10Jan-10Jun-10
H1 (3.5 m b.g.s.)M5 (3.5-4.5 m)M9 (3.5-4.5 m)M10 (2.5-3.5 m)
M5 (1.5-2.5 m)M5 (4.5-5.5 m)M9 (4.5-5.5 m)
M5 (2.5-3.5 m)M9 (1.5-2.5 m)M10 (1.5-2.5 m)
Figure 23.Precipitation and simulated percolation 1 m b.g.s. (A) together with the concentration of bifenox (B) andbifenox acid (C) in the drainage runoff, and the concentration of bifenox (D) and bifenox acid (E) in the groundwatermonitoring screens atSilstrup.The green vertical line indicates the date of bifenox application. Values below thedetection limit of 0.01 �g/l are shown as 0.01�g/l (all graphs) and further represented as open symbols in B and C.
58
DR (mm/d)
C
Bifenox-acidDrains
24
DR (mm/d)
B
BifenoxDrains
24
Percolation (mm/d)
0
Jun-10
Jan-10
Jul-09
Jul-09
75
May-09
Aug-09
Mar-09
Dec-09
Apr-10
Feb-10
Oct-09
Jun-09
Precipitation (mm/d)
10203040501B
60
A
453015032BentazoneDrains24168032
Pesticide (�g/l)
0.1
Pesticide (�g/l)
0.011C
241680321680
0.1
Pesticide (�g/l)
0.011D
0.10.01Pesticide concentrationDrainage runoffBentazoneMonitoring wells
Pesticide (�g/l)
1E0.10.01
Pesticide (�g/l)
1F
CyPMMonitoring wells
0.10.01May-09Mar-09Aug-09Dec-09Feb-10Oct-09Apr-10Jun-09Jun-10
M5 (1.5-2.5 m)H2 (3.5 m b.g.s.)
M5 (2.5-3.5 m)M10 (1.5-2.5 m)
M5 (3.5-4.5 m)M9 (1.5-2.5 m)
H1 (3.5 m b.g.s.)
Figure 24.Precipitation and simulated percolation 1 m b.g.s. (A) together with the concentration of bentazone (B),azoxystrobin (C) and CyPM (D) in the drainage runoff, and the concentration of bentazone (E) and CyPM (F) in thegroundwater monitoring screens atSilstrup.The green vertical lines indicate the dates of bentazone and azoxystrobinapplications. Values below the detection limit of 0.01 �g/l are shown as 0.01�g/l (all graphs) and further representedas open symbols in B, C and D.
59
DR(mm/d)
CyPMDrains
24
DR (mm/d)
AzoxystrobinDrains
DR (mm/d)
Percolation (mm/d)
0
Jun-10
75
60
5 Pesticide leaching at Estrup
5.1
Materials and methods
5.1.1 Site description and monitoring designEstrup is located in central Jutland (Figure 1) west of the Main Stationary Line on a hill-island, i.e. a glacial till preserved from the Weichselian Glaciation. Estrup has thus beenexposed to weathering, erosion, leaching and other geomorphological processes for amuch longer period than the other sites. The test field covers a cultivated area of 1.26 ha(105 x 120 m) and is virtually flat (Figure 25). The site is highly heterogeneous withconsiderable variation in both topsoil and aquifer characteristics (Lindhardtet al.,2001). Such heterogeneity is quite common for this geological formation, however.Based on three profiles excavated in the buffer zone bordering the field the soil wasclassified as Abrupt Argiudoll, Aqua Argiudoll and Fragiaquic Glossudalf (Soil SurveyStaff, 1999). The topsoil is characterised as sandy loam with a clay content of 10–20%,and an organic carbon content of 1.7–7.3%. A C-horizon of low permeability alsocharacterises the site. The saturated hydraulic conductivity in the C-horizon is 10-8m/s,which is about two orders of magnitude lower than at the other loamy sites (Table 1).The geological structure is complex comprising a clay till core with deposits of differentage and composition (Lindhardtet al.,2001). A brief description of the samplingprocedure is provided in Appendix 2. The monitoring design and test site are describedin detail in Lindhardtet al.(2001) and the analysis methods in Kjæret al.(2002). Pleasenote that the geological conditions only allowed one of the planned horizontal wells tobe installed.5.1.2 Agricultural managementManagement practice during the 2005-2009 growing seasons is briefly summarizedbelow and detailed in Appendix 3 (Table A3.4). For information about managementpractice during the previous monitoring periods, see previous monitoring reportsavailable on http://pesticidvarsling.dk/publ_result/index.html.On 6 April 2009, 30 kg/ha of KBr was applied as a tracer. Two days later the field wassown with spring barley (cv. Keops), which emerged 10 days later. On 1 May, at thebeginning of tillering, the herbicide bifenox was used. When on 14 May six tillers weredetectable,bentazone,and MCPA were used against weeds. Only bentazone wasincluded in the monitoring. On 4 June, when the first awns were visible, azoxystrobinwas used against fungi. At harvest on 7 August, barley yielded 71.4 hkg/ha of grain(85% DM) and 39.9 hkg/ha of straw (100 DM), the latter being shredded at harvest andploughed in on 24 August 2009. The yield of barley was about 25% above the averagefor the year and soil type (Plantedirektoratet, 2009).On the 24 August 2009 the field was ploughed and rotor-harrowed and sown withwinter rape (cv. Cabernet). The following day the herbicide clomazone was applied butnot included in the monitoring. The herbicide bifenox was used on 30 September whenfour leaves had unfolded. Pesticide treatment was applied on 9 October using61
cypermethrin, but the substance was not monitored. Due to poor overwintering of thewinter rape, the field was partially resown on 20 April 2010 using the spring rapevariety Pluto.An area of 2.265 m2was resown after a rotor-harrowing, whereas an area of 2.412 m2was resown without soil cultivation – direct seeding. The resown area amounted to 37%of the total field area. Thiacloprid was used against pests on 10 May and included in themonitoring programme. Harvest of the rape was a two-step procedure. On 23 Augustthe area grown with winter rape was harvested, yielding 38.3 hkg/ha (91% DM) and41.8 hkg being shredded at harvest (100% DM). On 23 August the section of the fieldgrown with spring rape was shredded, and the resulting biomass of 11.64 hkg/ha spreadon the surface. The field was ploughed on 14 September 2010.
Figure 25.Overview of theEstrupsite. The innermost white area indicates the cultivated land, while the grey areaindicates the surrounding buffer zone. The positions of the various installations are indicated, as is the direction ofgroundwater flow (by an arrow). Pesticide monitoring is conducted weekly from the drainage system (during periodof continuous drainage runoff) and monthly and half-yearly from selected groundwater monitoring wells as describedin Table A2.1 in Appendix 2.
62
5.1.3 Model setup and calibrationThe numerical model MACRO (version 5.1, Larsboet al.,2005) was applied to theEstrup site covering the soil profile to a depth of 5 m b.g.s., always including thegroundwater table. The model is used to simulate the water flow in the unsaturated zoneduring the monitoring period from July 2000 - June 2010 and to establish an annualwater balance.Compared to the setup in Rosenbomet al.(2010b), a year of validation was added to theMACRO setup for the Estrup site. The setup was subsequently calibrated for themonitoring period May 1999 June 2004 and validated for the monitoring period July2004 June 2010. For this purpose, the following time series have been used: theobserved groundwater table measured in the piezometers located in the buffer zone,measured drainage flow, and soil water content measured at two depths (25 and 40 cmb.g.s.) from the soil profile S1 (Figure 25). The TDR probes installed at the other depthsyielded unreliable data with saturations far exceeding 100% and unreliable soil waterdynamics with increasing soil water content during the drier summer periods (data notshown). No explanation can presently be given for the unreliable data, and they havebeen excluded from the analysis. The data from the soil profile S2 have also beenexcluded due to a problem with water ponding above the TDR probes installed at S2, asmentioned in Kjæret al.(2003). Finally, TDR-measurements at 25 cm b.g.s. inFebruary 2010 were discarded given freezing soils (soil temperatures at or below zerodegrees Celsius). The soil water content is measured with TDR based on Toppcalibration (Toppet al.,1980), which will underestimate the total soil water content atthe soil water freezing point as the permittivity of frozen water is much less than that ofliquid water (Flerchingeret al.,2006).Because of the erratic TDR data, calibration data are limited at this site. Dataacquisition, model setup as well as results related to simulated bromide transport aredescribed in Barleboet al.(2007).
5.2
Results and discussion
5.2.1 Soil water dynamics and water balancesThe model simulations were generally consistent with the observed data (which werelimited compared to other PLAP sites, as noted above), indicating a good modeldescription of the overall soil water dynamics in the unsaturated zone (Figure 26). Themodel provided an acceptable simulation of the overall level of the groundwater table.As in the previous hydrological year, a drop in the measured groundwater table wasseen after short periods of low precipitation (Figure 26B). Also here the simulatedgroundwater table did not seem as sensitive to these short periods of low precipitationand tended not to drop as much as the measured values. Since the subsoil TDR data arelimited, a more detailed study of soil water dynamics in these layers is difficult.However, the overall soil water saturation at 25 and 40 cm b.g.s. was captured (Figure26D and 26E). Nothing special is noted for the groundwater table in the latestmonitoring period (July 2009-June 2010). As in previous years (Rosenbomet al.,2010b), the simulated groundwater table often fluctuates slightly above the drain depthduring periods of drainage flow.
63
Figure 26.Soil water dynamics atEstrup:Measured precipitation and simulated percolation 0.6 m b.g.s. (A),simulated and measured groundwater level (B), simulated and measured drainage flow (C), and simulated andmeasured soil saturation (SW sat.) at two different soil depths (D and E). The measured data in B derive frompiezometers located in the buffer zone. The measured data in D and E derive from TDR probes installed at S1 (Figure23). The broken vertical line indicates the beginning of the validation period (July 2004-June 2010).
64
Table 10.Annual water balance forEstrup(mm/year). Precipitation is corrected to the soil surface according to themethod of Allerup and Madsen (1979).NormalActualMeasuredSimulated Groundwaterprecipitation2)Precipitation evapotranspirationdrainagedrainagerecharge3)1.7.99–30.6.001)9681173466–5531544)1.7.00–30.6.019688874203563401111.7.01–30.6.0296812905165055552701.7.02–30.6.039689394663293461441.7.03–30.6.049689284992983121311.7.04–30.6.059681087476525468861.7.05–30.6.069688974412583411991.7.06–30.6.0796813655155476183031.7.07–30.6.089681045478521556461.7.08–30.6.099681065480523362621.7.09–30.6.1096811905314995221601)Monitoring started in April 2000.2)Normal values based on time series for 1961–1990 corrected to the soil surface.3)Groundwater recharge is calculated as precipitation minus actual evapotranspiration minus measured drainage.4)Where drainage flow measurements are lacking, simulated drainage flow was used to calculate groundwaterrecharge.
The simulated drainage (Figure 26C) matched the measured drainage flow quite well.The initiation and magnitude of the spring 2010 drainage period was, however, not wellcaptured. The period preceding this drainage period can be characterised by frozen soiland precipitation in the form of snow – a situation which MACRO has difficulties indescribing. Drainage runoff over the whole monitoring period was high compared tothat of the other two till sites investigated in the PLAP. This was due to a significantlylower permeability of the C-horizon than of the overlying A and B horizons (see Kjæretal.(2005c) for details). Due to the extreme water flow generated during the snowmelton 28 February 2010, adequate measurement of the drainage flow as well as watersampling was not possible at the Estrup site. A similar situation occurred at the Silstrupsite and further information about the technical problems is given in section 4.2.1.The resulting water balance for Estrup for the entire monitoring period is shown inTable 10. Compared with the previous ten years, the latest hydraulic year July 2009-June 2010 was characterised by having the third-highest precipitation, the highestsimulated actual evapotranspiration and medium measured drainage. Even though themodel did not capture the snowmelt, there were no large differences between themeasured and simulated drainage. Precipitation in this year was characterised byNovember-December being very wet and January-February and May-June being verydry (Appendix 4). Due to this precipitation pattern, the simulated percolation pattern ofthe year July 2009-June 2010 left the summer without percolation, the autumn with highpercolation, and the winter with a decreasing percolation with scattered periods of bothpercolation and drainage runoff (Figure 26A, 26B, and 26C).
65
3
Suction cups - S1Bromide (mg/l)210
1 m b.g.s.
2 m b.g.s.
A
3Bromide (mg/l)
Suction cups - S2210
1 m b.g.s.
2 m b.g.s.
B
Bromide (mg/l)
4321001/04/200002/04/2001
Bromide, time-proportional samplingBromide, flow-proportional samplingDrainagerunoff
Drains
C483624120
03/04/2002
04/04/2003
04/04/2004
05/04/2005
06/04/2006
07/04/2007
07/04/2008
08/04/2009
3Bromide (mg/l)
H1.2
H1.1
H1.3
Horizontal wells3.5 m b.g.s.
D
210Apr-00Apr-01Apr-02Apr-03Apr-04Apr-05Apr-06Apr-07Apr-08Apr-09Apr-10
Figure 27.Bromide concentration atEstrup.A and B refer to suction cups located at S1 and S2, respectively. Thebromide concentration is also shown for drainage runoff (C) and the horizontal monitoring well H1 (D). In September2008, bromide measurements in the suction cups were suspended (Appendix 2). The green vertical lines indicate thedates of bromide applications.
5.2.2 Bromide leachingBromide has now been applied three times at Estrup. The bromide concentrationsmeasured up to October 2005 (Figure 27 and Figure 28) relate to the bromide applied inspring 2000, as described further in Kjæret al.(2003) and Barleboet al.(2007). InMarch 2009, bromide measurements in the suction cups and monitoring wells M3 andM7 were suspended.
66
09/04/2010
Drainage runoff (mm/d)
5
60
1.5-2.5 m b.g.sBromide (mg/l)
2.5-3.5 m b.g.s
3.5-4.5 m b.g.s
4.5-5.5 m b.g.sM2
2102
Bromide (mg/l)
M41
0Bromide (mg/l)
2
M5
1
0
Bromide (mg/l)
2M6
1
0Apr-00Apr-01Apr-02Apr-03Apr-04Apr-05Apr-06Apr-07Apr-08Apr-09Apr-10
Figure 28.Bromide concentration atEstrup.The data derive from the vertical monitoring wells (M2–M6). Screendepth is indicated in m b.g.s. In September 2008, monitoring wells M3 and M7 were suspended (Appendix 2). Thegreen vertical lines indicate the dates of bromide applications.
5.2.3 Pesticide leachingMonitoring at Estrup began in May 2000. Pesticides and degradation productsmonitored so far can be seen from Table 11. Pesticide application during the two mostrecent growing seasons (2008/2009 and 2009/2010) is shown together with precipitationand simulated precipitation in Figure 29. It should be noted that precipitation iscorrected to the soil surface according to Allerup and Madsen (1979), whereaspercolation (0.6 m b.g.s.) refers to accumulated percolation as simulated with theMACRO model (Section 5.2.1). Moreover, pesticides applied later than April 2010 arenot evaluated in this report and hence not included in Table 11.
67
Table 11.Pesticides analysed atEstrupwith the product used shown in parentheses. Degradation products are initalics. Precipitation (prec.) and percolation (perc.) are accumulated from the date of first application until the end ofmonitoring. 1st month perc. refers to accumulated percolation within the first month after application. Cmea nrefers toaverage leachate concentration in the drainage water within the first drainage season after application (See Appendix2 for calculation methods).Crop and analysed pesticidesApplicationEnd ofPrec. Perc.1stmonthCmeanDatemonitoring (mm) (mm) Perc. (mm)(�g/l)Spring barley 2000Metsulfuron-methyl (Ally)- triazinaminFlamprop-M-isopropyl (Barnon Plus 3)- flamprop (free acid)Propiconazole (Tilt Top)Fenpropimorph (Tilt Top)- fenpropimorphic acidDimethoate (Perfekthion 500 S)Pea 2001Glyphosate (Roundup Bio)- AMPABentazone (Basagran 480)- AIBAPendimethalin (Stomp SC)Pirimicarb (Pirimor G)- pirimicarb-desmethyl- pirimicarb-desmethyl-formamidoWinter wheat 2002Ioxynil (Oxitril CM)Bromoxynil (Oxitril CM)Amidosulfuron (Gratil 75 WG)MCPA (Metaxon)- 4-chlor,2-methylphenolPropiconazole (Tilt 250 EC)Pirimicarb (Pirimor G)- pirimicarb-desmethyl- pirimicarb-desmethyl-formamidoMay 00May 00Jun 00Jun 00Jun 00Oct 00May 01May 01Jun 01Apr 03Apr 03Apr 05Jul 02Jul 02Jul 10†Jul 08Jul 03Jul 0529902914493822112211145614342294104810482920001239910<0.01<0.020.020.010.01<0.01<0.02<0.010.540.170.03<0.01<0.010.01<0.02<0.020.041)0.011)<0.01<0.01<0.010.020.01<0.02<0.02
10484 4977762922084251362110961995
Nov 01Nov 01Apr 02May 02May 02Jun 02
Jul 03Jul 03Jul 04Jul 04Apr 05Jul 05Apr 06
158015802148209129202982
86086092892813361403
5252803958
Systematic chemical nomenclature for the analysed pesticides is given in Appendix 1.† Monitoring will continue during the following year. The values for prec. and perc. are accumulated up to July 2006.1)Drainage runoff commenced about two and a half months prior to the application of ioxynil and bromoxynil, and theweighted concentrations refer to the period from the date of application until 1 July 2002.
The current report focuses on pesticides applied from 2008 and onwards, while leachingrisk of pesticides applied before 2008 has been evaluated in previous monitoring reports(see http://pesticidvarsling.dk/publ_result/index.html).Azoxystrobin has now been applied three times at Estrup: 22 June 2004, 29 June 2006,and 13 June 2008 (Figure 30). The last application before then was in June 1998(Lindhardtet al.,2001). Following all three applications azoxystrobin and themetabolite CyPM leached to the depth of the drainage system at the onset of drainagedue to infiltration of excess rain. Concentrations in drainage water of both parent andmetabolite are shown in Figure 30. At all three applications, the surface had desiccationcracks. The maximum measured concentration of azoxystrobin was 1.4 �g/l on 24August 2006 and 2.1 �g/l of CyPM on 11 September 2008. The picture emerging fromFigure 30 is that the leaching of the parent compound to drainage water was alwayshighest within the year of spraying (Figure 30B). The following year concentrationswould always be lower, but tended to increase with each new application. Regarding themetabolite CyPM (Figure 30C), concentrations within the year of application were, onaverage, higher than those of the parent compound.
68
Table 11 continued.Pesticides analysed atEstrupwith the product used shown in parentheses. Degradationproducts are in italics. Precipitation (prec.) and percolation (perc.) are accumulated from the date of first applicationuntil the end of monitoring. 1st month perc. refers to accumulated percolation within the first month after application.Cmea nrefers to average leachate concentration in the drainage water within the first drainage season after application(See Appendix 2 for calculation methods).Crop and analysed pesticidesApplicationEnd ofPrec.Perc.1stmonthCmeanDatemonitoring (mm)(mm)perc. (mm)(�g/l)Fodder beet 2003Glyphosate (Roundup Bio)- AMPAEthofumesate (Betanal Optima)Metamitron (Goltix WG)- metamitron-desaminoPirimicarb (Pirimor G)- pirimicarb-desmethyl- pirimicarb-desmethyl-formamidoSpring barley 2004Fluroxypyr (Starane 180)Azoxystrobin (Amistar)- CyPMMaize 2005Terbuthylazine (Inter-Terbuthylazin)- desethyl-terbuthylazine- 2-hydroxy-terbuthylazine- desisopropyl-atrazine- 2-hydroxy-desethyl-terbuthylazineBentazone (Laddok TE)- AIBAGlyphosate (Roundup Bio)- AMPASpring barley 2006Florasulam (Primus)- florasulam-desmethylAzoxystrobin (Amistar)- CyPMWinter wheat 2007Mesosulfuron-methyl (Atlantis WG)- mesosulfuronChlormequat (Cycocel 750)Epoxiconazole (Opus)Glyphosate (Roundup Bio)- AMPAWinter wheat 2008Picolinafen (Pico 750 WG)- CL153815Tebuconazole (Folicur EC 250)Spring barley 2009Bifenox (Fox 480 SC)- bifenox acid- nitrofenBentazone (Basagran M75)Azoxystrobin (Amistar)- CyPMSep 02May 03May 03Jul 03Jul 10†Apr 06Apr 06Jul 05Jul 05Apr 06Jul 06Jul 0882892901290120713900137113719390505000.430.190.111.10.21<0.01<0.010.12<0.020.120.230.480.310.110.020.240.18<0.014.041)0.421)<0.01<0.030.030.13<0.011)<0.02<0.010.010.141)0.101)0.031)0.241)0.431)0.0020.153<0.010.050.040.38
May 04Jun 04
20734452
10302209
038
May 05
Jun 05Nov 05
Apr 09Jul 09Jul 08Apr 09Jul 08Jul 08Jul 10†
4247440633384247333833385191
2042205116282042162816282460
32323232321068
Jun 06Jun 06
Jul 08Jul 08
24422414
11631170
00
Oct 06Apr 07May 07Sep 07
Jul 08Jul 08Jul 08Jul 10†
2059133711993006
10956036001393
6304564
Oct 07Nov 07May 09
Mar 10Mar 10Jul 10†Jul 10†Jul 10†
270626581337
13011265520
527717
May 09Jun 09
12901250
504505
00
Systematic chemical nomenclature for the analysed pesticides is given in Appendix 1.† Monitoring will continue during the following year. The values for prec. and perc. are accumulated up to July 2009.1)Drainage runoff commenced prior to the application of pesticide and the weighted concentrations refer to the period fromthe date of application until 1 July the following year.
69
May
Aug
Nov
Mar
Dec
Apr
Sep
Feb
Oct
Jun
Jan
Jul
0
30202008/20091510503020152009/20101050PrecipitationBifenox (2009)Azoxystrobin (2008 & 2009)Bentazone (2009).Simulated percolation
Precipitation (mm/d)
20304050600
Precipitation (mm/d)
2030405060
Figure 29.Application of pesticides included in the monitoring programme and precipitation (primary axis) togetherwith simulated percolation 0.6 m b.g.s. (secondary axis) atEstrupin 2008/2009 (upper) and 2009/2010 (lower).
It is notable that concentrations of CyPM in the second year after spraying tended toincrease even more with each new application of azoxystrobin. When looking at thegroundwater there has so far been just one detection of azoxystrobin (0.011 �g/l on 24March 2010) in a horizontal well (data not shown). CyPM was found in thegroundwater, in particular during the two last years of monitoring. There have been fivedetections from vertical wells, ranging between 0.014 and 0.085 �g/l (Figure 30D andTable A5.4).Picolinafen was applied on 30 October 2007. Concentrations of picolinafen neverexceeded 0.1 �g/l in drainage water (Figure 31B). However, its degradation productCL153815 did so in several instances (Figure 31C), reaching a maximum of 0.5 �g/l on6 December 2007, and was 0.016 �g/l at its last detection on 3 April 2008. Bycomparing Figure 31B and Figure 31C, CL153815 can clearly be seen to be morepersistent than picolinafen. Nearly a year after application of picolinafen (26 February2009), CL153815 could be found in the drainage water at a concentration of 0.078 �g/l.
70
Percolation (mm/d)
10
25
Percolation (mm/d)
10
25
May-08
Precipitation (mm/d)
May-10
Aug-05
Dec-04
Dec-06
Apr-04
Apr-06
Sep-07
Sep-09
Jan-09
122436486010
24A181260AzoxystrobinDrains6040200
Pesticide (�g/l)
10.10.0110
Pesticide (�g/l)
10.10.01
40200
Aug-05
May-08
10
Pesticide concentrationCyPMMonitoring wells
Drainage runoff (DR)
302010
Pesticide (�g/l)
11
0.10.1
0.01Aug-05Dec-04Jun-06May-08
Dec-06Sep-05
Sep-07Mar-06
Jan-09Dec-06
Mar-07Sep-09
Mar-05
Dec-05
Sep-04
Apr-04
Sep-06
Jul-04
Jun-05
M5 (1.5-2.5 m)M4 (1.5-2.5 m)
H1 (3.5 m b.g.s.)M6 (1.5-2.5 m)
M5 (2.5-3.5 m)
Figure 30.Precipitation and simulated percolation 0.6 m b.g.s. (A) together with concentration of azoxystrobin (B)and CyPM (C) in the drainage runoff (DR on the secondary axis) atEstrup.Detections of CyPM in groundwatermonitoring screen are indicated in D. Azoxystrobin was only detected once in groundwater monitoring screens (seetext). The green vertical lines indicate the dates of applications. Open symbols in B and C indicate values below thedetection limit of 0.01 �g/l.
It was last detected on 26 February 2009 at 0.011 �g/l. Neither picolinafen norCL153815 were detected in groundwater (Table 5.4 in Appendix 5).
71
Jun-07
May-10
Apr-04
Dec-04
Apr-06
0.01
0
May-10
Apr-04
Apr-06
Dec-04
Dec-06
Sep-07
Jan-09
Sep-09
DR (mm/d)
CyPMDrains
60
C
DR (mm/d)
B
Percolation (mm/d)
0
30
May-08
May-09
Precipitation (mm/d)
May-10
Nov-07
Aug-08
Nov-08
Aug-09
Nov-09
Sep-07
Feb-08
Feb-09
Feb-10
10203040501
A
161284060
Pesticide (�g/l)
Picolinafen0.10.01
B
300
Pesticide (�g/l)
CL153815
C300
0.10.0110
Pesticide (�g/l)
TebuconazoleD
6040200DR (mm/d)
10.10.01May-08May-09May-10Feb-08Feb-09Nov-07Aug-08Nov-08Aug-09Nov-09Sep-07Feb-10
Pesticide concentration
Drainage runoff (DR)
Figure 31.Precipitation and simulated percolation (A) together with concentration of picolinafen (B),
CL153815 (C), and tebuconazole (E) in the drainage runoff (DR on the secondary axis) atEstrupin2007/2010. The green vertical lines indicate the dates of applicatios. Open symbols indicate values belowthe detection limit of 0.01 �g/l. While picolinafen and CL153815 were not detected in any samples fromgroundwater monitoring, tebuconazole was detected in five samples (see text).
Tebuconazole, applied on 22 October 2007, was seen in drainage water on severaloccasions and reached a maximum concentration of 2.0 �g/l on 20 November 2008,over a year after application. Out of 80 drainage water samples analysed, 17 containedconcentrations of tebuconazole above 0.1 �g/l (Figure 31D). Tebuconazole was,detected in five groundwater samples taken more than two years after the application.Maximum concentrations found were 0.11 and 0.12 �g/l in samples taken from twodifferent screens of a monitoring well on 24 March 2011 (Table A5.4 in Appendix 5).The herbicide bifenox was used on 1 May and on 30 September 2009. Less than twoweeks later 0.15 �g/l of bifenox was detected in the drainage water (Figure 32B).Following the second application, bifenox was found twice, this time in concentrationsless than 0.1 �g/l. The metabolite bifenox acid was found in connection with a smalldrain flow event on 9 September 2009 at a concentration of 1.9 �g/l (Figure 32C),whereas bifenox was below the detection limit of 0.01 �g/l. Following the application inSeptember there were only two detections of bifenox, both less than 0.1 �g/l (Figure72
DR (mm/d)
1
60
DR (mm/d)
Percolation (mm/d)
0
20
32B), whereas eight out of ten bifenox acid detections were above 0.1 �g/l (Figure32C). Bifenox acid leached from the root zone to the drainage system in an averageconcentration of 0.153 �g/l in the drainage water, whereas the figure for bifenox was0.002 �g/l (Table 11). Neither bifenox nor bifenox acid was found in the groundwatermonitoring screens.The highest concentration in drainage water of bentazone following the 14 May 2009application was 0.16 �g/l in connection with a small drain flow event in September2009 (Figure 32D). None of the subsequent concentrations were above 0.1 �g/l and theaverage yearly concentrations amounted to 0.05 �g/l (Table 11). Bentazone was foundfour times in groundwater monitoring screens; concentrations did, however, not exceed0.1 �g/l (Table A5.4, Appendix 5).
May-09
Precipitation (mm/d)
May-10
Nov-09
Mar-09
Mar-10
Sep-09
Jan-10
Jul-09
010203040501
20A161284060
Pesticide (�g/l)
Bifenox0.10.01
B
300
Pesticide (�g/l)
1010.10.01
Bifenox-acid
9060300DR (mm/d)DR (mm/d)
C
Pesticide (�g/l)
1Bentazone0.10.01May-09May-10Nov-09Mar-09Mar-10Sep-09Jan-10Jul-09
60D300
Pesticide concentration
Drainage runoff (DR)
Figure 32.Precipitation and simulated percolation (A) together with concentration of bifenox (B),bifenox acid (C), and bentazone (E) in the drainage runoff (DR on the secondary axis) atEstrupin2004/2010. The green vertical lines indicates the dates of applications. Open symbols indicate valuesbelow the detection limit of 0.01 �g/l. While bifenox and bifenox acid were not detected in any samplesfrom groundwater monitoring, bentazone was detected in four samples (see text).
73
DR (mm/d)
Percolation (mm/d)
Sep-04
Sep-05
Sep-06
Sep-07
Sep-08
0Precipitation (mm/d)10203040100
Sep-09
Oct-00
Oct-01
Oct-02
Oct-03
201510A5056
Glyphosate (�g/l)
Glyphosate1010.10.0110
BDR (mm/d)42281405436180
AMPA (�g/l)
10.10.01
Oct-00
Oct-01
Oct-02
Oct-03
Sep-04
Sep-05
Sep-06
Sep-07
Sep-08
Time-proportional sampling1Pesticide (�g/l)
Flow-proportional sampling
Drainage runoff (DR)
Sep-09
Glyphosate0.1
D
Pesticide (�g/l)
0.011AMPA
E
0.1
0.01Oct-00Oct-01Oct-02Oct-03Sep-04Sep-05Sep-06Sep-07Sep-08Sep-09
M4 (1.5-2.5 m)M5 (2.5-3.5 m)M1 (3.5-4.5 m)M6 (2.5-3.5 m)
M4 (2.5-3.5 m)M5 (3.5-4.5 m)M3 (1.5-2.5 m)M6 (3.5-4.5 m)
M4 (3.5-4.5 m)M5 (4.5-5.5 m)M3 (2.5-3.5 m)
M4 (4.5-5.5 m)H1 (3.5 m b.g.s.)M3 (3.5-4.5 m)
M5 (1.5-2.5 m)M1 (4.5-5.5 m)M6 (1.5-2.5 m)
Figure 33.Precipitation and simulated percolation 0.6 m b.g.s. (A) together with the concentration of glyphosate (B)andAMPA (C) in the drainage runoff (DR. on the secondary axis) atEstrup.Data represent a nine-year
period including four applications of glyphosate as indicated by the green vertical lines. Open symbolsindicate values below the detection limit of 0.01 �g/l. Detection of glyphosate and AMPA in groundwatermonitoring wells is shown in D and E. In the period June 2007 until July 2010, marked with the redoutlined box, analytical problems caused the concentration of glyphosate to be underestimated (see textfor details).
The herbicide glyphosate has now been applied at Estrup in 2000, 2002, 2005, and 2007(Figure 33). Following all applications, both glyphosate and AMPA could be found inthe drainage water. Out of 400 drainage water samples analysed for glyphosate andAMPA in the period 31 October 2000-19 May 2010, the concentrations of glyphosateand AMPA exceeded 0.1 �g/l in 89 and 98 samples, respectively (Figure 33B and 33C).In the same period, 708 groundwater samples were analysed for glyphosate and 712 forAMPA. During that period AMPA never exceeded 0.1 �g/l (Figure 33E and Table A5.4in Appendix 5), whereas glyphosate did so in three samples, of which two were takenon 7 July 2005 from two different wells, concentrations being 0.67 and 0.59 �g/l, and74
DR (mm/d)
AMPA
C
Percolation (mm/d)
one on 13 January 2010 from a third well with a concentration of 0.17 �g/l (Figure 33Dand Table A5.4 in Appendix 5). In Figure 33, the period June 2007 to July 2010 hasbeen put inside a red box to indicate that within this period, analytical problems causedglyphosate to be underestimated. Results from the external quality assurance reveal thatin the period June 2007 to July 2010 the concentrataion of glyphosate may have beenunderestimated by a factor of up to ~2 as compared to previous periods (See section7.2.2.).When comparing the three-year periods following the application of glyphosate inSeptember 2002 and September 2007, a pattern of longevity/persistence seems toemerge, in particular for the metabolite AMPA. Three years following spraying withglyphosate there will still be a leaching of AMPA, whereas that of glyphosate is muchless (Figure 33B and Figure 33C). This long-term leaching of AMPA may indicate thatAMPA is retained within the soil and gradually released over a very long time, asdescribed in Kjæret al.(2005a), or that glyphosate is retained within the soil and thengradually degraded into AMPA. With an increased detection of glyphosate in thegroundwater samples at Estrup following high precipitation events in September 2005(nearly three years after latest application), September 2008 and January 2010 (one andtwo and a half years after the latest application, respectively), evidence of the latterpattern seems also to be recognizable.It is remarkable that detections of particularly glyphosate in groundwater monitoringwells seem to increase over the years (Figure 33D). Within the first four years,detections of glyphosate were scarce, and AMPA is not found at all (Figure 33E).Following these four years there is a gradual increase, particularly in detections andconcentrations of glyphosate. A similar tendency was observed for AMPA, althoughdetections are less frequent and the concentrations comparatively lower. In this respectitshould be noted that there had been no application of glyphosate for at least seven yearsprior to the 2000 application (Lindhardtet al.,2001).Pesticide leaching at Estrup is mostly confined to the depth of the drainage system.Apart from AMPA, CyPM, bentazone, desethyl-terbuthylazine, deisopropylatrazine,and glyphosate having been detected in 8, 9, 16, 7, 27, and 39 groundwater samples,respectively, pesticides have only sporadically been detected in groundwater monitoringscreens below the depth of the drainage system (Appendix 5, Table A5.4). Due todecreased hydraulic conductivity and a lower degree of preferential flow, transport ofwater and solutes at Estrup is much slower beneath the drainage system than above it.Slow transport may allow for dispersion, dilution, sorption and degradation, therebyfurther reducing the deep transport. Compared to the other loamy soils investigated, theretention characteristics at Estrup suggest that the C-horizon (situated beneath thedrainage depth) is less permeable with a lower degree of preferential flow occurringthrough macropores (see Kjæret al.,2005c, for details). An indication thereof are thelong periods with groundwater table beyond drainage depth in which an increasinglateral transport to the drainage system and decreased leaching to the deepergroundwater will occur.
75
76
6 Pesticide leaching at Faardrup
6.1
Materials and methods
6.1.1 Site description and monitoring designFaardrup is located in southern Zealand (Figure 1). The test field covers a cultivatedarea of 2.3 ha (150 x 160 m). The terrain slopes gently to the west by 1–3� (Figure 34).Based on three profiles in the buffer zone bordering the field, the soil was classified asHaplic Vermudoll, Oxyaquic Hapludoll and Oxyaquic Argiudoll (Soil Survey Staff,1999). The topsoil is characterised as sandy loam with 14–15% clay and 1.4% organiccarbon. Within the upper 1.5 m numerous desiccation cracks coated with clay arepresent. The test field contains glacial deposits dominated by sandy till to a depth ofabout 1.5 m overlying a clayey till. The geological description shows that smallchannels or basins filled with meltwater clay and sand occur both interbedded in the tilland as a large structure crossing the test field (Lindhardtet al.,2001). The calcareousmatrix and the reduced matrix begin at 1.5 m and 4.2 m b.g.s., respectively.The dominant direction of groundwater flow is towards the west in the upper part of theaquifer (Figure 34). During the monitoring period the groundwater table was located 1–2 and 2–3 m b.g.s. in the lower and upper parts of the area, respectively. Duringfieldwork within the 5 m deep test pit it was observed that most of the water enteringthe pit came from an intensely horizontally-fractured zone in the till at a depth of 1.8–2.5 m. The intensely fractured zone could very well be hydraulically connected to thesand fill in the deep channel, which might facilitate parts of the percolation. Thebromide tracer study showed, however, that virtually none of the applied bromidereached the vertical monitoring well (M6) located in the sand-filled basin (Figure 35and Figure 38), thus indicating that hydraulic contact with the surface in the “basin”does not differ from that in other parts of the test field, and that the basin is a small pondfilled with sediments from local sources.A brief description of the sampling procedure is provided in Appendix 2. Themonitoring design and test site are described in detail in Lindhardtet al.(2001) and theanalysis methods in Kjæret al.(2002).
77
Figure 34.Overview of theFaardrupsite. The innermost white area indicates the cultivated land, while the greyarea indicates the surrounding buffer zone. The positions of the various installations are indicated, as is the directionof groundwater flow (by an arrow). Pesticide monitoring is conducted weekly from the drainage system (duringperiod of continuous drainage runoff) and monthly and half-yearly from selected groundwater monitoring wells asdescribed in Table A2.1 in Appendix 2.
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Figure 35.Geological description ofFaardrup(Lindhardtet al.,2001).
79
6.1.2 Agricultural managementManagement practice during the two recent growing seasons is briefly summarizedbelow and detailed in Appendix 3 (Table A3.5). For information about managementpractice during the previous monitoring periods, see previous monitoring reportsavailable on http://pesticidvarsling.dk/publ_result/index.html.On 26 August 2008, 30 kg/ha of KBr was applied as a tracer. Ploughing of the fieldtook place 1 December 2008. On 5 April 2009 a crop of sugar beets (cv. Palace) wassown, emerging on 16 April. The first weed spraying was done on 24 April, when thefirst leaf was visible (pinhead-size) and the cotyledons horizontally unfurled, usingphenmedipham and metamitron. On 30 April, when the first pair of beet leaves werevisible, but not yet unfurled (pea-size), weeds were sprayed with triflusulfuron,metamitron, ethofumesate and phenmedipham. The latter was not included in themonitoring, however. On 11 May, where the plants had four leaves unfurled, weedswere again sprayed with triflusulfuron, metamitron, ethofumesate and phenmedipham,and again the latter was not included in the monitoring. Due to problems with couchgrass (Agropyrum repens, L.), cycloxydim was used twice: on 14 May where fiveleaves had unfurled, and on 17 June when the beets covered from 10-40% of the area.Cycloxydim was not included in the monitoring programme. The sugar beets wereharvested on 6 October, yielding 348.23 hkg/ha of beets and 189.3 hkg/ha of top (freshweight). The top was ploughed in on 1 November 2009.On 22 April 2010 the field was sown with a mixture of spring barley varieties. Thebarley was undersown with red fescue (cv. Maximum). When four to six tillers weredetectable on the barley it was sprayed with the herbicide bentazone. The fungicideazoxystrobin was applied on 2 July, but not included in the monitoring. The barley washarvested on 21 August yielding 58.5 hkg/ha of grain (85% DM) and approximately 27hkg/ha of straw (100% DM).6.1.3 Model setup and calibrationThe numerical model MACRO (version 5.1) was applied to the Faardrup site coveringthe soil profile to a depth of 5 m b.g.s., always including the groundwater table. Themodel was used to simulate the water flow in the unsaturated zone during the fullmonitoring period September 1999-June 2010 and to establish an annual water balance.Compared to the setup in Rosenbomet al.(2010b), a year of validation was added to theMACRO setup for the Faardrup site. The setup was accordingly calibrated for themonitoring period May 1999-June 2004 and validated for the monitoring period July2004-June 2010. For this purpose, the following time series were used: observedgroundwater table measured in the piezometers located in the buffer zone, water contentmeasured at three depths (25, 60, and 110 cm b.g.s.) from the two profiles S1 and S2(Figure 34) and measured drainage flow. Data acquisition and model setup aredescribed in Barleboet al.(2007).
80
Table 12.Annual water balance forFaardrup(mm/year). Precipitation is corrected to the soil surface according tothe method of Allerup and Madsen (1979).NormalActualMeasuredSimulated Groundwaterprecipitation1)Precipitation2)evapotranspirationdrainagedrainagerecharge3)1.7.99–30.6.00626715572192152-501.7.00–30.6.0162663938350352061.7.01–30.6.02626810514197201991.7.02–30.6.0362663648049721071.7.03–30.6.0462668550536191441.7.04–30.6.0562667146913155721.7.05–30.6.0662655737228161581.7.06–30.6.07626796518202212771.7.07–30.6.0862664552211165121.7.08–30.6.0962671346346212041.7.09–30.6.1062662444554481251)2)
Normal values based on time series for 1961–1990.For July 1999-June 2002, July 2003-June 2004, in January and February of both 2005 and 2006, and July 2006-June2007, measured at the DIAS Flakkebjerg meteorological station located 3 km from the test site (see detailed text above).3)Groundwater recharge is calculated as precipitation minus actual evapotranspiration minus measured drainage.
Due to electronic problems, precipitation measured at Flakkebjerg located 3 km east ofFaardrup was used for the monitoring periods: July 1999-June 2002, July 2003-June2004, January and February of both 2005 and 2006, and July 2006-June 2007.Precipitation measured locally at Faardrup was used for the rest of the monitoringperiod.
6.2
Results and discussion
6.2.1 Soil water dynamics and water balancesThe level and dynamics of the soil water saturation in all three horizons in the hydraulicyear July 2009-June 2010 were generally well described by the model (Figure 36D,36E, and 36F). However, for the summer period 2010 the model underestimated thedrop in the measured groundwater table (Figure 36B).The resulting water balance for Faardrup for the 11 monitoring periods is shown inTable 12. Compared with the previous ten years, the latest hydraulic year July 2009-June 2010 was characterised by having the second-lowest precipitation, the third-lowestsimulated actual evapotranspiration, and the sixth-lowest measured and fifth-lowestsimulated drainage. Precipitation in this year was characterised by August, January, andFebruary being very dry and November and May being very wet (Appendix 4). Due tothis precipitation pattern, the duration of the simulated percolation period of the yearJuly 2009-June 2010 was represented by continuous percolation throughout the periodNovember - June (Figure 36A). Compared to the other years, the climate this year gaverise to a short period, where the groundwater table was a bit higher than the drainagelevel, causing a low short-term contribution to the drains (Figure 36B and 36C).
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Figure 36.Soil water dynamics atFaardrup:Measured precipitation and simulated percolation 1 m b.g.s. (A),simulated and measured groundwater level GWT (B), simulated and measured drainage flow (C) and simulated andmeasured soil water saturation (SW sat.) at three different soil depths (D, E, and F). The measured data in B derivefrom piezometers located in the buffer zone. The measured data in D, E and F derive from TDR probes installed at S1and S2 (Figure 32). The broken vertical line indicates the beginning of the validation period (July 2004-June 2010).
82
9Bromide (mg/l)
Suction cups - S1
630
1 m b.g.s.2 m b.g.s.
A
9Bromide (mg/l)
Suction cups - S2
1 m b.g.s.2 m b.g.s.
B
6306
DrainsBromide (mg/l)4
C10
2
5
0
0
9Bromide (mg/l)
Horizontal wells - 3.5 m b.g.s.
H1.3H2.3
H1.1H2.1
H1.2H2.5
D
630May-99May-00May-01May-02May-03May-04May-05May-06May-07May-08May-09May-10
Figure 37.Bromide concentrations atFaardrup.A and B refer to suction cups located at S1 and S2. The bromideconcentration is also shown for drainage runoff (C) and the horizontal monitoring wells (D). In September 2008,bromide measurements in the suction cups were suspended. The green vertical lines indicate the dates of bromideapplications.
6.2.2 Bromide leachingThe bromide concentration shown in Figure 37 and Figure 38 relates primarily to thebromide applied in May 2000, as described further in Kjæret al.(2003), and furtherevaluated in Barleboet al.(2007). In August 2008, 30 kg/ha potassium bromide wasapplied for the second time. In September 2008, bromide measurements in the suctioncups and monitoring wells M2 and M7 were suspended. A drastic increase in bromideconcentration in M4 and M5 was detected in May-June 2009 (Figure 38).83
Drainage runoff (mm/d)
Bromide, time-proportional samplingBromide, flow-proportional samplingDrainage runoff
15
Bromide (mg/l)Bromide (mg/l)Bromide (mg/l)Bromide (mg/l)
Bromide (mg/l)Bromide (mg/l)
0
1
2
00120101May-99May-00May-01May-02May-03May-04May-05May-06May-07May-08May-09May-07May-06May-05May-04May-03May-02May-01May-00May-99
12
2
0
1
2
2
May-99May-99May-99
May-00May-00May-00
1.5-2.5 m b.g.s.
May-01May-01May-02May-03May-04May-05May-06May-07May-08May-09
May-01
May-02
May-02
May-03
May-03
2.5-3.5 m b.g.s.
May-04
May-04
Figure 38.Bromide concentrations atFaardrup.The data derive from the vertical monitoring wells (M2–M7).Screen depth is indicated in m b.g.s. In September 2008, monitoring wells M2 and M7 were suspended (Appendix 2).The green vertical line indicates the dates of bromide applications.
84
May-05
May-05
May-06
May-06
3.5-4.5 m b.g.s.
May-07
May-07
May-08
May-08
May-08
May-09
May-09
May-09
M6
M2
M5
M4
4.5-5.5 m b.g.s.
M7
M3
May-10May-10
May-10
May-10
May-10
May
Aug
Nov
0Precipitation (mm/d)
Mar
Dec
Apr
Sep
Feb
Oct
Jun
Jan
Jul
12102008/2009864201282009/20106420PrecipitationBromide (2008)Triflusulfuron-methyl, metamitron & ethofumesate (2009)Simulated percolationPercolation (mm/d)Percolation (mm/d)
1020304050600
Precipitation (mm/d)
102030405060
10
Figure 39.Application of pesticides included in the monitoring programme and precipitation (primary axis) togetherwith simulated percolation (secondary axis) atFaardrupin 2008/09 (upper) 2009/2010 (lower).
6.2.3 Pesticide leachingMonitoring at Faardrup began in September 1999 and presently encompasses severalpesticides and their degradation products, as indicated in Table 13. The application timeof the pesticides included in the monitoring during the two most recent growing seasonsis shown together with precipitation and simulated precipitation in Figure 39. It shouldbe noted that precipitation is corrected to the soil surface according to Allerup andMadsen (1979), whereas percolation (1 m b.g.s.) refers to accumulated values assimulated with the MACRO model. It should also be noted that as e.g. tribenuronmethyl(applied as Express) degrades rapidly, the leaching risk is more associated with itsdegradation product, triazinamin-methyl. For the same reason it is the degradationproduct and not the parent compounds that is monitored in the PLAP (Table 13).
85
Table 13.Pesticides analysed atFaardrupwith the product used shown in parentheses. Degradation products are initalics. Precipitation (prec.) and percolation (perc.) are accumulated from the date of first application (app. date) untilthe end of monitoring. 1stmonth perc. refers to accumulated percolation within the first month after application. Cmeanrefers to average leachate concentration in the drainage water the first drainage season after application (SeeAppendix 2 for calculation methods).Crop and analysed pesticidesApplicationEnd ofPrec.Perc.1stmonthCmeanDatemonitoring (mm)(mm)perc. (mm)(�g/l)Winter wheat 1999Glyphosate (Roundup 2000)- AMPABromoxynil (Briotril)Ioxynil (Briotril)Fluroxypyr (Starane 180)Propiconazole (Tilt Top)Fenpropimorph (Tilt Top)- fenpropimorphic acidPirimicarb (Pirimor G)- pirimicarb-desmethyl- pirimicarb-desmethyl-formamidoSugar beet 2001Glyphosate (Roundup 2000)- AMPAMetamitron (Goltix WG)- metamitron-desaminoEthofumesate (Betanal Optima)Desmedipham (Betanal Optima)- EHPCPhenmedipham (Betanal Optima)- MHPCFluazifop-P-butyl (Fusilade X-tra)- fluazifop-P (free acid)Pirimicarb (Pirimor G)- pirimicarb-desmethyl- pirimicarb-desmethyl-formamidoSpring barley 2002Flamprop-M-isopropyl (Barnon Plus 3)- flamprop-M (free acid)MCPA (Metaxon)- 4-chlor-2-methylphenol- triazinamin-methyl1)(Express)Dimethoate (Perfekthion 500 S)Propiconazole (Tilt 250 EC)Aug 99Oct 99Oct 99Apr 00May 00May 00Jun 00Apr 03Apr 02Apr 02Apr 02Jul 03Jul 02Jul 032526173817381408215115182066947751751494669491684035357000<0.01<0.01<0.01<0.01<0.01<0.01<0.01<0.01<0.01<0.01<0.02<0.010.010.010.010.06<0.01<0.02<0.01<0.02<0.010.02<0.01<0.01<0.02<0.01<0.01<0.01<0.02<0.02<0.01<0.01
Oct 00May 01May 01May 01May 01Jun 01Jul 01
Jul 03Jul 03Jul 03Jul 03Jul 03Jul 03Jul 03
1747151215121512151214601460
709507507507507503503
0444401
May 02May 02May 02Jun 02Jun 02
Jul 04Jul 04Jul 04Jul 04Jul 04
13371358135813281328
333337337333333
04400
Systematic chemical nomenclature for the analysed pesticides is given in Appendix 1.1)Degradation product of tribenuron-methyl. The parent compound degrades too rapidly to be detected by monitoring.
The current report focuses on the pesticides applied from 2008 and onwards, while theleaching risk of pesticides applied before 2008 has been evaluated in previousmonitoring reports (see http://pesticidvarsling.dk/publ_result/index.html).
86
Table 13 continued.Pesticides analysed atFaardrupwith the product used shown in parentheses. Degradationproducts are in italics. Precipitation (prec.) and percolation (perc.) are accumulated from the date of first application(app. date) until the end of monitoring. 1stmonth perc. refers to accumulated percolation within the first month afterapplication. Cmeanrefers to average leachate concentration in the drainage water the first drainage season afterapplication (See Appendix 2 for calculation methods). The number of pesticide-positive samples is indicated inparentheses.Crop and analysed pesticidesApplication End ofPrec.Perc.1stmonthCmeanDatemonitoring(mm)(mm)perc. (mm)(�g/l)Winter rape 2003Clomazone (Command CS)- FMC65317 (propanamide-clomazon)Winter wheat 2004Prosulfocarb (Boxer EC)MCPA (Metaxon)- 4-chlor,2-methylphenolAzoxystrobin (Amistar)- CyPMMaize 2005Terbuthylazine (Inter-Terbutylazin)- desethyl-terbuthylazine- 2-hydroxy-terbuthylazine- desisopropyl-atrazine- 2- hydroxy-desethyl-terbuthylazineBentazone (Laddok TE)- AIBASpring barley 2006Fluroxypyr (Starane 180 S)Epoxiconazole (Opus)Winter Rape 2007Thiamethoxam (Cruiser RAPS)- CGA 322704Propyzamide (Kerb 500 SC)- RH-24644- RH-24580- RH-24655Winter wheat 2008Pendimethalin (Stomp)Tebuconazole (Folicur EC 250)Sugar beet 2009Triflusulfuron (Safari)-IN-D8526-IN-E7710-IN-M7222Ethofumesate (Ethosan)Metamitron (Goliath)- Metamitron-desaminoAug 02Apr 0517615094<0.02<0.02<0.01<0.01<0.01<0.01<0.010.670.590.040.030.072.82<0.01<0.02<0.01<0.01<0.020.1381)<0.011)<0.011)<0.011)<0.01<0.01<0.01<0.01<0.01<0.01<0.01<0.01<0.01
Oct 03Jun 04Jun 04
Apr 06Jul 06Jul 07
154213072098
454331636
000
May 05May 05May 05May 05May 05May 05
Jul 08Jul 08Jul 08Jul 08Jul 07Jul 07
207820782078207814281408
666666666666465464
4
46
May 06Jun 06Aug 06Feb 07
Jul 08Jul 08Jul 08Apr 09
1496144113041476
524507505375
1732746
Oct 07Nov 07Apr 09
Dec 09Dec 09Jul 10†
14621405769
451413210
24562
Apr 09Apr 09
Jul 10†Jul 10†
769769
210210
22
Systematic chemical nomenclature for the analysed pesticides is given in Appendix 1.† Monitoring will continue during the following year. The values for prec. and perc. are accumulated up to July 2009.1)Drainage runoff commenced prior to the application of propyzamide and the weighted concentrations refer to the periodfrom the date of application (Feb 07) until 1 July 2007.
Tebuconazole and pendimethalin were applied in 2007 and these pesticides have untilnow been detected in five and two samples (data not shown, see Rosenbomet al.,2010b), respectively. Measured concentrations, however, never exceeded 0.1 �g/l.Triasulfuron-methyl was applied in April 2009, but neither the parent compound nor itsdegradations products have so far been detected.Metamitron, ethofumesate and triflusulfuron were applied April 2009 (Figure 39) and sofar neither of the pesticides nor their metabolites have been detected in water samplesfrom Faardrup.
87
88
7 Pesticide analysis quality assurance
Reliable results and scientifically valid methods of analysis are essential for the integrityof the present monitoring programme. Consequently, the field monitoring work hasbeen supported by intensive quality assurance entailing continuous evaluation of theanalyses employed. Two types of sample are used in the quality control – samples withknown pesticide composition and concentration are used forinternal monitoringof thelaboratory method, whileexternally spiked samplesare used to incorporate additionalprocedures such as sample handling, transport and storage. Pesticide analysis qualityassurance (QA) data for the period July 2009 to June 2010 are presented below, whilethose for the preceding monitoring periods are given in previous monitoring reports(available on http://pesticidvarsling.dk/publ_result/index.html).
7.1 Materials and methodsAll pesticide analyses were carried out at commercial laboratories selected on the basisof a competitive tender. In order to assure the quality of the analyses, the call for tendersincluded requirements as to the laboratory’s quality assurance (QA) system comprisingboth an internal and an external control procedure. In addition to specific quality controlunder the PLAP, the laboratory takes part in the proficiency test scheme employed bythe Danish Environmental Protection Agency when approving laboratories for theNationwide Monitoring and Assessment Programme for the Aquatic and TerrestrialEnvironments (NOVANA).7.1.1 Internal QAWith each batch of samples the laboratory analysed one or two control samplesprepared at each laboratory as part of their standard method of analysis. The pesticideconcentration in the internal QA samples ranged between 0.03–0.13 �g/l. Using thesedata it was possible to calculate and separate the analytical standard deviation intowithin-day (Sw), between-day (Sb) and total standard deviation (St). Total standarddeviation was calculated using the following formula (Wilson 1970, Danish EPA 1997):22st=sw+sb
7.1.2 External QAEvery four months, two external control samples were analysed at the laboratories alongwith the various water samples from the five test sites. Two stock solutions of differentconcentrations were prepared from two standard mixtures in ampoules prepared by Dr.Ehrenstorfer, Germany (Table 14). Fresh ampoules were used for each set of standardsolutions. The standard solutions were prepared two days before a sampling day andstored in darkness and cold until use. For the preparation of stock solutions 150 �l (lowlevel) or 350 �l (high level) of the pesticide mixture was pipetted into a preparationglass containing 10 ml of ultrapure water. The glass was closed and shaken thoroughly89
and shipped to the staff collecting the samples. The staff finished the preparation ofcontrol samples in the field by quantitatively transferring the standard solution to a 3.0 lmeasuring flask. The standard solution was diluted and adjusted to the mark withgroundwater from a groundwater well. In the present report period the finalconcentrations correspond to 50 and 117 �g/l in the final solution for low and high spikelevels, respectively. After a thorough mixing, the control sample was transferred to asample bottle and transported to the laboratories together with the regular samples. Aswater sample supply was occasionally limiting at Faardrup, all volumes were reducedby a factor of three for this location, keeping the concentrations in the final controlsamples identical to the other locations.The pesticide concentration in the solution is indicated in Table 14. Blank samplesconsisting of HPLC water were also included in the external QA procedure everymonth. All samples included in the control sample were labelled with coded referencenumbers, so that the laboratory was unaware of which samples were controls and whichwere blanks.Table 14.Pesticide concentrations in both the original ampoules and in the resulting high-level and low-levelexternal control samples.CompoundAmpouleHigh-level controlLow-level controlConcentration (mg/l)Ampoule(�g/l)(�g/l)AMPA1.00020.1170.050CyPM1.00010.1170.050Bentazone1.00010.1170.050Bifenox (free acid)1.00010.1170.050CL1538151.00010.1170.050Epoxiconazole1.00010.1170.050Ethofumesate1.00010.1170.050Glyphosate1.00020.1170.050IN70941 (PPU)1.00010.1170.050IN-M72221.00010.1170.050Metsulfuron-methyl1.00010.1170.050Metamirton1.00010.1170.050Pendimethalin1.00010.1170.050Tebuconazole1.00010.1170.050TFMP1.00010.1170.050
7.2
Results and discussion
7.2.1 Internal QAIdeally, the analytical procedure provides precise and accurate results. However, in thereal world results from analysis are subject to a certain standard deviation. Suchstandard deviation may be the combined result of several contributing factors. Overall,the accuracy of an analytical result reflects two types of error: Random errors related toprecision and systematic errors relating to bias. In a programme like PLAP it is relevantto consider possible changes in analytical “reliability over time”. As these errors maychange over time it is relevant to distinguish between standard deviations resulting fromwithin-dayvariation as opposed to those associated withbetween-dayvariation in theanalytical result. To this end, control samples are included in the analytical process asdescribed above. Thus, by means of statistical analysis of the internal QA data it ispossible to separate and estimate the different causes of the analytical variation in twocategories: day-to-day variation and within-day variation (Milleret al.,2000; Funketal.,1995). This kind of analysis can provide an indication of the reliability of the90
analytical results used in the PLAP. The statistical tool used is an analysis of variance(ANOVA) and encompasses all duplicate pesticide analyses, single analyses beingexcluded. The analysis can be divided into three stages:1.Normality:An initial test for normality is made as this is an underlyingassumption for the one-way ANOVA.2.Between-day contribution:Explained simply, this test will reveal any day-to-day contribution to the variance in the measurements. If there is none, the totalstandard deviation can be considered to be attributable to the within-day error ofthe analysis. For this purpose an ANOVA-based test is used to determine if thebetween-day standard deviation (Sb) differs significantly from 0 (this test ismade as an F-test with the H0:between-day mean square = within-day meansquare).3.Calculating standard deviations:If the F-test described above reveals acontribution from the between-day standard deviation (Sb), it is relevant tocalculate three values: The within-day standard deviation Sw, the between-daystandard deviation Sb, and the total standard deviation St.As the error associated with the analytical result is likely to be highly dependent on thecompound analysed, the QA applied is pesticide-specific. The results of the internal QAstatistical analysis for each pesticide are presented in Table 15. For reference, estimatedSbvalues are listed for all pesticides, including those for which the between-dayvariance is not significantly greater than the within-day variance. ANOVA details andvariance estimates are also included, even for pesticides where the requirement fornormality is not fulfilled. Such data should obviously be interpreted with caution.As a rule of thumb, the between-day standard deviation should be no more than doublethe within-day standard deviation. From Table 15 it can be seen that Sb/Swratios greaterthan two were observed for several compounds. For these compounds, the resultsindicate that day-to-day variation makes a significant contribution. Among thecompounds meeting the normality requirement, the Sb/Sw ratio is highest for PPU,desethyl-terbuthylazine and desisopropyl-atrazine. When all compounds are considered,a particularly high Sb/Swratio is apparent for desethyl-terbuthylazine and triazinamine.Such relatively high ratios can be caused by very low within-day standard deviations,i.e. within each laboratory day, the variation on the analysis is small compared to theother compounds, whereas the variation between days is comparable to the othercompounds analysed. This is the case for desethyl-terbuthylazine. Thus, low values ofSw rather than critical values of Sb caused the high ratios, as reflected by a reasonablylow St. In contrast, for the compound triazinamine and others it is apparent that it is thebetween-day(Sb)contribution that is causing a high Sb/Sw ratio. As reflected by thedata in Table 15, the three compounds with the highest observed between-daycontribution were triazinamine, bifenox acid and picolinafen.The total standard deviations (St) of the various analyses of pesticides and degradationproducts lie within the range 0.005-0.652 �g/l, the highest value being observed fortriazinamin (max Stfor compounds other than triazinamine was 0.044 �g/l). In general,the data suggest that the analytical procedure used for the quantification of triazinaminemay benefit from a critical review. Excluding the triazinamine data, the overall mean Stwas 0.014 �g/l.91
Table 15.Internal QA of pesticide analyses carried out in the period 1.7.2008-30.6.2009. Results of the test fornormality, one-way analysis of variance (ANOVA), the estimated values of standard deviations (w: within-day, b:between-day, t: total – see text for details), pesticide concentration in internal QA sample (Conc.) and number ofduplicate samples (n) are given for each pesticide. For test the P valueα=0.05was used.CompoundNormalSignificant SbSwSbStRatioNConc.distribution Between day(�g/l) (�g/l) (�g/l) Sb/Sw(�g/l)contributionα=0.05ANOVAα=0.05AMPA*0.016 0.006 0.017 0.38 270.03Azoxystrobinyesyes0.002 0.006 0.006 2.93 480.05Bentazoneyes0.001 0.005 0.005 5.83 480.05Bifenoxyes0.007 0.010 0.012 1.43 340.05Bifenox acid*yes0.017 0.041 0.044 2.33 300.10CL153815*yes0.012 0.029 0.031 2.37 260.13Desethyl-terbuthylazine*yes0.001 0.017 0.017 17.28 30.05Epoxiconazoleyesyes0.003 0.007 0.008 2.47 70.05Glyphosate0.010 0.005 0.011 0.56 270.03IN70941*yesyes0.003 0.014 0.014 4.88 240.05IN70942*yes0.001 0.008 0.008 6.78 240.05Iodosulfuron-methylyes0.005 0.000 0.005 0.10 50.05Mesosulfuron*yesyes0.003 0.008 0.008 2.49 50.10Mesosulfuron-methylyesyes0.008 0.014 0.017 1.70 60.05Metribuzin-diketo*yesyes0.002 0.006 0.006 3.54 120.05Metsulfuron-methyl*0.016 0.012 0.020 0.72 50.05Nitrofen*yesyes0.002 0.010 0.010 4.39 340.05Pendimethalin0.009 0.006 0.011 0.61 140.05Picolinafenyes0.016 0.029 0.033 1.76 260.11Tebuconazoleyes0.003 0.008 0.008 3.00 380.05Triazinamin*yes0.051 0.650 0.652 12.73 150.11*Degradation product.
7.2.2 External QAAs part of the qualíty control a set of blanks are analysed to evaluate the possibility offalse positive findings in the programme. From these results it can be concluded thatcontamination of samples during collection, storage and analysis is not likely to occur.In a total of 26 blank samples consisting of HPLC water a trace of glyphosate (< 0.02�g/l well below the residue limit of 0.1 �g/l and close to the detection limit) was foundin a single sample. Samples found to contain pesticides or their degradation product arethus regarded as true positive findings.Table 16 provides an overview of the recovery of all externally spiked samples. As theresults for each field site in Table 16 are based on only a few observations for eachconcentration level (high/low), the data should not be interpreted too rigorously.
92
Table 16.Externally spiked samples. Average recovery (%) of the nominal concentration at low/high concentrationlevel indicated for each site. nlowand nhighrefer to the total number of samples being spiked at low and highconcentrations, respectively. Bold font is used for recoveries outside the range 70% to 120%.TylstrupJyndevadSilstrupEstrupFaardrupAverage nlow/nhigh
Low High LowAMPA*Bentazone102Bifenox acid*CL153815*CyPM*87EpoxiconazoleEthofumesateGlyphosateIN70941(PPU)*34IN-M7222*MetamitronMetsulfuron-methyl*Pendimethalin84Tebuconazole113TFMP**Degradation produkt.1021007290174
High1026870153
Low
High
Low High Low High8662110102111126607875676410458541168710011810879102119102
99266141130746782111135123157
99
1227468104133102
74 3/3105 10/1064 [0/5]75 3/378 6/61641/1101 5/6573/3424/6120 5/678 5/6683/392 2/2115 7/71463/3
Whereas the recovery of the most spiked compounds in the samples is generally good(i.e. in the range 70% to 120%), the broad range of average recoveries indicates that forsome compounds there may be reason for concern. In the current reporting period oneexception has been made concerning spiking, as traces of Bifenox acid, CyPM andbentazone were found in the groundwater used for spiking at Silstrup, and data from thissite have been omitted due to this bias. The somewhat low levels of recovery found forbifenox acid at Jyndevad and Estrup indicate that the the QA needs to be reevaluated forthis compound when more results are available (at present the QA is based on fivesamples). Also, the detection limit for Bifenox acid at 0.05 makes the QA spiking lessinformative at this level compared to the other compounds in the programme that havedetection limits around 0.01 and 0.02 Considering the low recovery of glyphosate,identified in previous reports, analytical procedures have now been optimised andimplemented in the programme with effect from 1 July 2010 and will thus be reflectedin the next reporting period. However, it is anticipated that the QA data in the reports tofollow will verify the improved methodologies for this compound. In the programme ashift from GC/MS to LC/MS analytical procedure was made in June 2007. The lowrecoveries relate to the analytical LC/MS procedure used in the programme during thethe period June 2007 to July 2010. During this period the concentration of glyphosatemay have been underestimated. Due to the analytical cause of the problem, it is notpossible to give an exact value for such a possible underestimation. However, apreliminary estimate has been made using all the QA data available for glyphosate andAMPA, i.e. all spiked QA samples analysed for these two compounds in the periodOctober 2007 to June 2010. For glyphosate the mean recovery was 86% (n=73, std dev24%) compared to 40% (n=18, std dev 16%) using LC/MS. For AMPA the GC/MSrecoveries were 76% (n=31, std dev 24%) compared to 68% (n=16, std dev 15%) usingLC/MS. A simple t-test indicates that there is a difference in the recoveries forglyphosate (P< 0.001), whereas no significant difference was found for the AMPArecovery. A rough estimate based on the mean recovery obtained using the twoglyphosate methods would indicate that analytical results reported in the period June2007 to July 2010 may have underestimated the concentration of glyphosate by a factorof ~2 as compared to previours result based on a GC/MS analysis.
93
All the compounds included in the spiking procedure (Table 14) were detected in thelaboratory. Additionally, a number of compounds were measured at the threshold ofdetection of the analytical procedure (i.e. close to 0.01 �g/l). The occurrence of alimited number of false positives is expected when analysing environmental matrices,and these findings do not cause a general concern in relation to the reliability of theanalytical procedures used in the programme. Also, there were 12 reportings with amean content of 0.05 �g/l for the compound PPU-desamino (IN70942), which was notincluded in the spiking ampoule. The compound PPU –desamino (IN70942) is adegradation product of PPU (IN70941), which was included in the spiking, and thepresence of a degradation product indicates that the estimated leaching of PPU(IN70941) may be underestimated as described in Rosenbomet al.(2009). The sameaspect relates to 11 reportings of metamitron-desamino, a degradation product ofmetamitron that was included in the spike solution. Thus, these compounds may beformed from compounds present in the spiking solution, In general, since the levelswere low and in the range of the detection limit and well below the residue limit, thesefindings do not cause concern for the overall quality of the programme.During the 2009/2010 monitoring period a total of five pesticides and nine degradationproducts were detected in samples from the experimental fields, and the external andinternal QA data relating to these particular pesticides/degradation products are ofspecial interest. These data (when available) are therefore illustrated in Appendix 6.
7.3 Summary and concluding remarksThe QA system showed that:•The internal QA indicates that the reproducibility of the pesticide analyses was goodwith total standard deviation (St) in the range 0.005-0.044 �g/l, except fortriazinamin with a large St of 0.652 caused in particular by Sb.As demonstrated by the external QA, recovery was generally good in externallyspiked samples. Low recovery of glyphosate was, however, observed in all samples,but a revision of the analytical procedure being implemented in parallel with thecurrent reporting period is anticipated to solve these issues in the PLAP-programme.Contamination of samples during collection, storage and analysis is not likely tooccur. In a single sample out of a total of 26 blank samples a trace of glyphosate wasreported. No other pesticides or pesticide degradation products were detected.
•
•
94
8 Summary of monitoring results
This section summarizes the monitoring data from the entire monitoring period, i.e. bothdata from the two most recent monitoring years (detailed in this report) and data fromthe previous monitoring years (detailed in previous reports available onhttp://pesticidvarsling.dk/publ_result/index.html). Pesticide detections in samples fromthe drainage systems, suction cups and monitoring wells are detailed in Appendix 5.The monitoring data in 1 m b.g.s. (collected in drains and suction cups) reveal that theapplied pesticides exhibit three different leaching patterns – no leaching, slight leachingand pronounced leaching (Table 17). Pronounced leaching in 1 m b.g.s. is defined asroot zone leaching (1 m b.g.s.) exceeding an average concentration of 0.1 �g/l withinthe first season after application. On sandy and loamy soils, leaching is determined asthe weighted average concentration in soil water and drainage water, respectively(Appendix 2). The monitoring data from the groundwater monitoring screens is dividedinto three categories: no detection of the pesticide (or its degradation products),detections of the pesticide (or its degradation products) not exceeding 0.1 �g/l, anddetections of the pesticide (or its degradation products) exceeding 0.1 �g/l (Table 19). Itshould be noted, though, that the present evaluation of the leaching risk of some of thesepesticides is still preliminary as their potential leaching period extends beyond thecurrent monitoring period. This applies to those pesticides marked with a single asteriskin Table 17 and 19. Fourteen of the applied pesticides (or their degradation products)exhibited pronounced root zone leaching and 12 of these were also detected in thegroundwater monitoring screens in concentrations exceeding 0.1 �g/l.•Azoxystrobin, and in particular its degradation product CyPM, leached from the rootzone (1 m b.g.s.) in high average concentrations at the loamy sites Silstrup andEstrup. CyPM leached into the drainage water in average concentrations exceeding0.1 �g/l at both the Silstrup and Estrup sites, while azoxystrobin only leached inconcentrations exceeding 0.1 �g/l at Estrup (Table 17 and 18). At both sites,leaching of azoxystrobin and CyPM has hitherto mostly been confined to the depthof the drainage system, and they have rarely been detected in monitoring screenssituated below drainage depth (Tables 19 and 20). However, detection of CyPM ingroundwater monitoring wells has gradually increased over time with highestnumbers of detection found after the latest applications (2009 at Silstrup, Figure 24and 2008 at Estrup, Figure 30). Apart from one sample, however, concentrationsdetected were all below 0.1 �g/l. At the loamy Faardrup site azoxystrobin andCyPM were detected in only four samples from the drainage water, and in nosamples from the sandy Jyndevad site (Appendix 5).
95
Table 17.Root zone leaching(1 m b.g.s.)of pesticides or their degradation products at the five PLAP sites. Anasterisk indicates pesticides that have been included in the monitoring programme for less than two years. Thecolours indicate the degree of leaching and the letters H, F, I, and GR indicate the type of pesticide: herbicide,fungicide, insecticide and growth retardant, respectively. Pesticides applied in spring 2010 are not included in thetable.TylstrupJyndevadSilstrupEstrupFaardrup(Sandy soil)(Sandy soil)(Loamy soil)(Loamy soil)(Loamy soil)
Azoxystrobin (F)Bentazone (H)Bifenox (H)**Ethofumesate (H)2)2)Fluazifop-P-butyl (H)*Glyphosate (H)Metamitron (H)1)Metribuzin (H)*Picolinafen (H)Pirimicarb (I)Propyzamide (H)Rimsulfuron (H)Terbuthylazine (H)Tebuconazole (F)2)Amidosulfuron (H)Bromoxynil (H)Clomazone (H)Dimethoate (I)Epoxiconazole (F)Flamprop-M-isopropyl (H)Fluroxypyr (H)Ioxynil (H)Mancozeb(F)MCPA (H)Mesosulfuron-methyl (H)Pendimethalin (H)Phenmedipham (H)Propiconazole (F)Prosulfocarb (H)Pyridate (H)Triflusulfuron (H)Chlormequat (GR)Clopyralid (H)Desmedipham (H)Fenpropimorph (F)Florasulam (H)Iodosulfuron-methyl-sodium (H)Linuron (H)Metsulfuron-methyl (H)Thiamethoxam (I)Tribenuron-methyl (H)Triasulfuron (H)*Potential leaching period extends beyond the current monitoring period.1)Derived from application before May 1999 (see Kjæret al.,2002).2)Degradation products are not monitored (see text).
*2)
*
2)
*
Pesticide (or its degradation products) leached 1 m b.g.s. in average concentrations exceeding 0.1 �g/l withinthe first season after application.Pesticide (or its degradation products) was detected in either several (more than three) consecutive samples orin a single sample in concentrations exceeding 0.1 �g/l; average concentration (1 m b.g.s.) below 0.1 �g/lwithin the first season after application.Pesticide either not detected or only detected in very few samples in concentrations below 0.1 �g/l.
96
Table 18.Number of samples from1 m b.g.s.in which the various pesticides and their degradation products weredetected at each site with the maximum concentration (�g/l) in parentheses. The table only encompasses thosepesticides/degradation products detected in either several (more than three) consecutive samples or in a single samplein concentrations exceeding 0.1�g/l.Degradation products are indicated in italics. Pesticides applied in spring 2010are not included.TylstrupJyndevadSilstrupEstrupFaardrup
Azoxystrobin-CyPMBentazone-AIBABifenox-Bifenox acid-NitrofenEthofumesate-fluazifop-P2)-TFMP2)Glyphosate-AMPAMetamitron-metamitron-desaminoMetribuzin-metribuzin-desamino-diketo-metribuzin-diketoPicolinafen-CL153815Pirimicarb-pirimicarb-desmethyl-pirimicarb-desmethyl-Propyzamide-RH24580-RH24644-RH24655-PPU3)-PPU-desamino3)Terbuthylazine-desethylterbuthylazine-desisopropyl-atrazine-2-hydroxy-desethyl--2-hydroxy-terbuthylazinTebuconazoleAmidosulfuronBromoxynilClomazone-FMC65317(Propanamide-clomazone)DimethoateEpoxiconazoleETU1)Flamprop-M-isopropyl-flamprop (free acid)FluroxypyrIoxynilMCPA-4-chlor-2-methylphenolMesosulfuron-methylPendimethalinPhenmedipham-MHPCPropiconazoleProsulfocarbPyridate-PHCPTriflusulfuron-IN-E77101)2)
001(0.012)0
0039(1.6)2(0.034)2(0.036)1(0.1)0001(0.014)
0
10(0.034)64(0.34)45(6.4)01(0.027)13(4.2)1(0.023)15(0.227)021(0.52)67(4.7)122(0.35)31(0.315)46(0.399)
100(1.4)184(2.1)145(20)1(0.06)3(0.15)11(1.9)35(3.362)0251(31)356(1.6)42(26.369)49(5.549)
04(0.059)18(43)1(0.057)
13(12)8(3.8)4(0.093)10(0.11)12(1.7)16(2.5)
2(0.024)81(2.1)242(0.69)0000000122(0.15)35(0.042)02(0.012)17(0.042)5(0.016)1(0.04)0000007(0.038)0000
003(0.088)1(0.015)001(0.011)0
14(0.054)1(0.052)023(1.6)2(0.016)15(0.051)060(1.55)108(1.08)43(0.041)*28(0.11)*26(0.039)*
17(0.07)31(0.5)39(0.077)026(0.379)
7(0.056)6(0.053)3(0.039)4(0.51)04(0.022)1(0.017)41(10)89(8.3)25(0.36)8(1)21(0.58)4(0.045)01(0.28)0001(0.037)1(0.089)1(0.19)1(0.011)2(0.28)1(0.24)2(0.041)02(0.19)0000
154(0.29)89(0.13)018(0.056)
03(0.11)0001(1.417)012(0.109)7(0.096)00014(0.064)006(0.033)5(0.18)04(2.69)05(0.014)
111(11)145(8.2)71(0.44)86(6.3)87(0.99)41(2)03(0.6)013(0.39)20(0.069)13(0.031)3(0.025)20(0.25)11(3.894)1(0.046)13(0.059)
00
00000000
25(0.862)
Degradation product of mancozeb.Degradation product of fluazifop-P-butyl3)Degradation product of rimsulfuron.*Included in the monitoring at Silstrup from February 2003, eight months after application of terbuthylazine.
97
Table 19.Detections of pesticides and their degradation products in water samples fromthe groundwatermonitoring screensat the five PLAP sites (see table 20 for details). An asterisk indicates pesticides that have beenincluded in the monitoring programme for less than two years. The colours indicate the level of detection (see below)and the letters H, F, I, and GR indicate the type of pesticide: herbicide, fungicide, insecticide and growth retardant,respectively. Pesticides applied in spring 2010 are not included in the table.TylstrupJyndevadSilstrupEstrupFaardrup(Sandy soil)(Sandy soil)(Loamy soil)(Loamy soil)(Loamy soil)
Azoxystrobin (F)Bentazone (H)***BifenoxEthofumesate (H)2)2)2)Fluazifop-P-butyl (H)Glyphosate (H)Metamitron (H)1)Metribuzin (H)Picolinafen (H)Pirimicarb (I)Propyzamide (H)Rimsulfuron (H)Terbuthylazine (H)Tebuconazole (F)2)2)Amidosulfuron (H)Bromoxynil (H)Clomazone (H)Dimethoate (I)Epoxiconazole (F)Flamprop-M-isopropyl (H)Fluroxypyr (H)Ioxynil (H)Mancozeb (F)MCPA (H)Mesosulfuron-methyl (H)Pendimethalin (H)Phenmedipham (H)Propiconazole (F)Prosulfocarb (H)Pyridate (H)*Triflusulfuron (H)Chlormequat (GR)Clopyralid (H)Desmedipham (H)Fenpropimorph (F)Florasulam (H)Iodosulfuron-methyl-sodium (H)Linuron (H)Metsulfuron-methyl (H)Thiamethoxam (I)Tribenuron-methyl (H)Triasulfuron (H)*Potential leaching period extends beyond the current monitoring period.1)Derived from application before May 1999 (see Kjæret al.,2002).2)Degradation products are not monitored (see text).Pesticide (or its degradation products) detected in water samples from groundwater monitoring screens inconcentrations exceeding 0.1 �g/l.Pesticide (or its degradation products) detected in water samples from groundwater monitoring screens inconcentrations not exceeding 0.1 �g/l.Pesticide (or its degradation products) not detected in water samples from the groundwater monitoring screens.
98
Table 20.Number of samples from thegroundwater monitoring screensin which the various pesticides and/ortheir degradation products were detected at each site with the maximum concentration (�g/l) in parentheses (seeAppendix 5 for further details). Degradation products are indicated in italics. Pesticides applied in spring 2010 are notincluded.TylstrupJyndevadSilstrupEstrupFaardrup
Azoxystrobin-CyPMBentazone-AIBABifenox-Bifenox acid-nitrofenEthofumesate-fluazifop-P2)-TFMP2)Glyphosate-AMPAMetamitron-metamitron-desaminoMetribuzin-metribuzin-desamino-diketo-metribuzin-diketoPicolinafen-CL153815Pirimicarb-pirimicarb-desmethyl-pirimicarb-desmethyl-Propyzamide-RH24580-RH24644-RH24655-PPU3)-PPU-desamnino3)Terbuthylazine-desethyl-terbuthylazine-desisopropyl-atrazine-2-hydroxy-desethyl--2-hydroxy-terbuthylazinTebuconazoleAmidosulfuronBromoxynilClomazone- FMC65317(Propanamide-clomazone)Dimethoate-ETU1)EpoxiconazoleFlamprop-M-isopropyl-flamprop (free acid)FluroxypyrIoxynilMCPA-4-chlor-2-methylphenolMesosulfuron-methylPendimethalinPhenmedipham-MHPCPropiconazoleProsulfocarbPyridate-PHCPTriflusulfuron-IN-M7222DesmediphamFenpropimorph-fenpropimorph-acidMetsulfuron-methyl-triazinamin1)
0000
00002(0.05)00002(0.022)
0
028(0.1)29(0.44)05(0.1)13(3.1)05(0.038)1(0.072)48(0.29)4(0.031)15(0.08)29(0.168)30(0.19)
1(0.011)9(0.085)16(0.022)1(0.026)0000039(0.67)8(0.07)00
0011(0.6)0
31(1.4)6(0.17)3(0.017)2(0.029)24(0.63)48(1.3)
1(0.014)236(0.204)453(0.554)00000002(0.045)0001(0.014)1(0.026)01(0.011)00002(0.024)0000
020(1.831)26(1.372)00000
3(0.011)009(0.14)02(0.032)036(0.124)161(0.143)4(0.047)*1(0.016)*0*
001(0.015)00
2(0.035)3(0.042)2(0.076)1(0.033)00051(1.9)66(0.94)60(0.04)7(0.092)34(0.069)1(0.01)0000001(0.072)1(0.01)0002(0.025)1(0.053)1(0.035)0
284(0.11)71(0.028)024(0.023)
1(0.022)7(0.053)27(0.034)5(0.12)00
1(0.014)0001(0.011)0000000001(0.024)000000001(0.027)014(0.309)01(0.052)1(0.033)001(0.085)
0001(0.058)01(0.019)00
00
2(0.022)
00
1(0.029)0
Degradation product of mancozeb.2)Degradation product of fluazifop-P-butyl.3)Degradation product of rimsulfuron.*Included in the monitoring at Silstrup from February 2003, eight months after application of terbuthylazine.99
0001(0.042)
01(0.015)0
•
Bentazone leached through the root zone (1 m b.g.s.) in average concentrationsexceeding 0.1 �g/l in the drainage system at the loamy sites of Silstrup, Estrup, andFaardrup. Moreover, bentazone was frequently detected in the monitoring screenssituated beneath the drainage system at Silstrup and Faardrup (Table 19 and 20).Apart from eight samples, however, concentrations detected were all below 0.1 �g/l.At Estrup leaching was mostly confined to the depth of the drainage system andrarely detected in deeper monitoring screens (Appendix 5). On the sandy soils,bentazone leached at Jyndevad, but was only detected once 1 m b.g.s. at Tylstrup. AtJyndevad high concentrations (exceeding 0.1 �g/l) were detected in the soil watersamples from suction cups 1 m b.g.s. four months after application. Thereafter,leaching diminished and bentazone was not subsequently detected in the monitoringwells. Although leached in high average concentrations (>0.1 �g/l) at four sites,bentazone was generally leached within a short period of time. Initial concentrationsof bentazone were usually very high, but then decreased rapidly. In general,concentrations exceeding 0.1�g/l were only found within a period of one to fourmonths following the application. The degradation product AIBA was detectedtwice in the vadose zone at Jyndevad, once in drainage water at Estrup and Faardrup(Table 18), and once in water from a horizontal well at Estrup (Table 20).Bifenox acid (degradation product of bifenox) leached through the root zone andentered the drainage water system in average concentrations exceeding 0.1 �g/l atthe loamy sites of both Silstrup and Estrup. While leaching at Estrup seems to beconfined to the depth of the drainage system, leaching to groundwater monitoringwells situated beneath the drainage system was observed at Silstrup, whereconcentrations exceeding 0.1 �g/l were observed up to six months after application..Similar evidence of pronounced leaching wasnotobserved on the coarse sandy soilas there was only a single detection of bifenox acid in soil water, whereas bifenoxwas detected very sporadically in soil and groundwater, concentrations always lessthan 0.1 �g/l.In the loamy soil of Estrup, ethofumesate, metamitron, and its degradation productmetamitron-desamino leached through the root zone (1 m b.g.s.) into the drainagewater in average concentrations exceeding 0.1 �g/l (Table 17). The compounds havenot been detected in deeper monitoring screens. These compounds also leached 1 mb.g.s. at the Silstrup and Faardrup sites, reaching both the drainage system (Table 17and 18) and groundwater monitoring screens (Table 19 and 20). Averageconcentrations in drainage water were not as high as at Estrup, althoughconcentrations exceeding 0.1 �g/l were observed in both drainage water andgroundwater monitoring screens during a 1–6-month period at both Silstrup andFaardrup (see Kjæret al.,2002 and Kjæret al.,2004 for details). The aboveleaching was observed following an application of 345 g/ha of ethofumesate and2,100 g/ha of metamitron in 2000 and 2003. Since then, ethofumesate has beenregulated and the leaching risk related to the new admissible dose of 70 g/ha wasevaluated with the two recent applications (2008 at Silstrup and 2009 at Faardrup).Although metamitron has not been regulated, a reduced dose of 1400 g/ha wasapplied at the two recent applications. The leaching following these recentapplications (2008 at Silstrup and 2009 at Faardrup) with reduced dose of bothethofumesate and metamitron was minor. Apart from a few samples from thedrainage system and groundwater monitoring wells containing less than 0.1 �g/l,
•
•
100
neither ethofumesate nor metamitron was found in any of the analysed watersamples (see section 4.2.3 and 6.2.3).•Fluazifop-P-butyl has several times been included in the monitoring programme atJyndevad, Tylstrup, Silstrup, and Faardrup. As fluazifop-P-butyl rapidly degrades,until July 2008 monitoring has focused only on its degradation product fluazifop-P(free acid). Except for one detection below 0.1 �g/l in groundwater at Silstrup and17 detections with eight exceeding 0.1 �g/l (four drains, three vadose zone, onegroundwater, Table 18 and 20) at Faardrup, leaching was not evident. TFMP, thedegradation product of fluazifop-P-butyl, was included in the monitoringprogramme at Silstrup in July 2008 following an application of fluazifop-P-butyl.After approximately one month, TFMP was detected in the groundwater monitoringwells, where concentrations at or above 0.1 �g/l were detected within a ten-monthperiod following application (Figure 22, Tables 19 and 20). At the onset of drainageflow in September, TFMP was detected in all the drainage water samples atconcentrations exceeding 0.1 �g/l (Figure 22). The leaching pattern of TFMPindicates pronounced preferential flow also in periods with a relatively dry vadosezone.Glyphosate and AMPA was found to leach through the root zone at high averageconcentrations on loamy soils. At the loamy sites Silstrup and Estrup, glyphosate hasbeen applied two (in 2001 and 2003) and four (in 2000, 2002, 2005, and 2007) timeswithin the monitoring period, respectively. All six autumn applications have resultedin detectable leaching of glyphosate and AMPA from the upper meter into thedrainage water, often at concentrations exceeding 0.1 �g/l several months afterapplication. Higher leaching levels of glyphosate and AMPA have mainly beenconfined to the depth of the drainage system and have rarely been detected inmonitoring screens located below the depth of the drainage systems, although itshould be noted that detections of particularly glyphosate in groundwater monitoringwells at Estrup seem to increase over the years (Figure 33D). This increase may beunderestimated for the period June 2007 to July 2010 as external quality assuranceof analytical methods in this period indicates that the true concentration ofglyphosate may be underestimated (see section 7.2.2 ). On two occations heavy rainevents and snowmelt triggered leaching to the groundwater monitoring wells inconcentrations exceeding 0.1 �g/l more than two year after the application (Figure33D). Numbers of detections exceeding 0.1 �g/l in groundwater monitoring wellsare, however, very limited (only three samples). Glyphosate and AMPA were alsodetected in drainage water at the loamy site of Faardrup (as well as at the nowdiscontinued Slaeggerup site), but in low concentrations (Kjæret al.,2004).Evidence of glyphosate leaching was only seen on loamy soils, whereas the leachingrisk was negligible on the coarse sandy soil of Jyndevad. Here, infiltrating waterpassed through a matrix rich in aluminium and iron, thereby providing goodconditions for sorption and degradation (see Kjæret al.,2005a for details).Two degradation products of metribuzin – metribuzin-diketo and metribuzin-desamino-diketo – leached 1 m b.g.s. at average concentrations exceeding 0.1 �g/l inthe sandy soil at Tylstrup. Both degradation products appear to be relatively stableand leached for a long period of time. Average concentrations reaching 0.1 �g/lwere seen as late as three years after application (Table 17). Evidence was alsofound that their degradation products might be present in the groundwater several101
•
•
years after application, meaning that metribuzin and its degradation products havelong-term sorption and dissipation characteristics (Rosenbomet al.,2009). At bothsandy sites (Tylstrup and Jyndevad), previous applications of metribuzin has causedmarked groundwater contamination with its degradation products (Kjæret al.,2005b).•At Estrup, CL153815 (degradation product of picolinafen) leached through the rootzone upper meter into the drainage water in average concentrations exceeding 0.1�g/l (Appendix 5). CL153815 has not been detected in deeper monitoring screens(Table 20). Leaching of CL153815 have not been observed on the sandy soil atJyndevad, (Table 17, Table 20, and Appendix 5).Pirimicarb together with its two degradation products pirimicarb-desmethyl andpirimicarb-desmethyl-formamido has been included in the monitoring programmefor all five sites. All of the three compounds have been detected, but onlypirimicarb-desmethyl-formamido leached through the root zone (1 m b.g.s.) enteringthe drainage system in average concentrations exceeding 0.1 �g/l (Table 17) atEstrup. Comparable high levels of leaching of pirimicarb-desmethyl-formamidohave not been observed with any of the previous applications of pirimicarb at theother PLAP sites (Table 17 and Kjæret al.,2004). Both degradation products(pirimicarb-desmethyl and pirimicarb-desmethyl-formamido) have been detected indeeper monitoring screens at Faardrup (Table 19 and 20).Propyzamide leached through the root zone (1 m b.g.s.) at the loamy Silstrup andFaardrup sites, entering the drainage system at average concentrations exceeding 0.1�g/l (Table 17 and 18). Propyzamide was also detected in the monitoring screenssituated beneath the drainage system. Apart from a few samples at Silstrup, theconcentrations in the groundwater from the screens were always less than 0.1 �g/l(Appendix 5, Table 19 and 20).One degradation product of rimsulfuron – PPU – leached from the root zone (1 mb.g.s.) in average concentrations reaching 0.10–0.13 �g/l at the sandy soil site atJyndevad. Minor leaching of PPU was also seen at the sandy site Tylstrup, wherelow concentrations (0.021-0.11 �g/l) were detected in the soil water sampled 1 and 2m b.g.s (Tables 17 and 18). In groundwater PPU was occasionally detected andtwice exceeded 0.1 �g/l at Jyndevad, whereas it was only detected once (and at alow concentration) at Tylstrup (Table 19 and 20). At both sites, PPU was relativelystable and persisted in the soil water for several years, with relatively little furtherdegradation into PPU-desamino. E.g. average leaching concentrations reaching 0.1�g/l were seen as much as three years after application at Jyndevad. With an overalltransport time of about four years, PPU reached the downstream monitoring screens.Thus, the concentration of PPU-desamino was much lower and apart from foursamples at Jyndevad, never exceeded 0.1 �g/l. It should be noted that theconcentration of PPU is likely to be underestimated by up to 22-47%. Results fromthe field-spiked samples thus indicate that PPU is unstable and may have furtherdegraded to PPU-desamino during analysis (Rosenbomet al.,2010a).Terbuthylazine as well as its degradation products leached through the root zone (1m b.g.s.) at high average concentrations on loamy soils. At the three loamy soil sitesSilstrup, Estrup, and Faardrup, desethyl-terbuthylazine leached from the upper meter102
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•
•
•
entering the drainage water in average concentrations exceeding 0.1 �g/l (Table 17and 18). Four years after application at Estrup, both terbuthylazine and desethyl-terbuthylazine were detected in drainage water, but not exceeding 0.1 �g/l. AtSilstrup (Kjæret al.,2007) and Faardrup (Kjæret al.,2009), desethyl-terbuthylazinewas frequently detected in the monitoring screens situated beneath the drainagesystem (Table 19 and 20) at concentrations exceeding 0.1 �g/l during a 2- and 24-month period, respectively. Leaching at Estrup (Kjæret al.,2007) was confined tothe drainage depth, however. Minor leaching of desethyl-terbuthylazine was alsoseen at the two sandy sites Jyndevad and Tylstrup, where desethyl-terbuthylazinewas detected in low concentrations (<0.1 �g/l) in the soil water sampled 1 m b.g.s.While desethyl-terbuthylazine was not detected in the groundwater monitoringscreens at Tylstrup, it was frequently detected in low concentration (< 0.1 �g/l) atJyndevad (Table 20, Kjæret al.,2004). Marked leaching of terbuthylazine was alsoseen at two of the three loamy sites (Estrup and Faardrup), the leaching pattern beingsimilar to that of desethyl-terbuthylazine. 2-hydroxy-desethyl-terbuthylazine and 2-hydroxy-terbuthylazine leached at both Faardrup and Estrup and at the latter site theaverage drainage concentration exceeded 0.1 �g/l. Leaching of these twodegradation products was at both sites confined to the drainage system. None of thetwo degradation products were detected in groundwater monitoring screen at Estrup,whereas at Faardrup both were found, but at low frequencies of detection andconcentrations.•Tebuconazole has been applied in autumn 2007 at Tylstrup, Jyndevad, Estrup andFaardrup. Only on the loamy soil of Estrup did it leach through the root zone (1 mb.g.s.) and into the drainage water in average concentrations exceeding 0.1 �g/l(Table 17 and 18). Leaching was mainly confined to the depth of the drainagesystem, although the snow melt occurring in March 2011 (more than two years afterapplication) induced leaching of tebuconazole to the groundwater monitoring well inconcentrations exceeding 0.1 �g/l (Tables 19 and 20). None of the applications atthe three other PLAP sites caused tebuconazole to be detected in similarly highconcentrations in the vadose zone, though concentrations below 0.1 �g/l have beendetected in a few samples from the groundwater monitoring screens (Table 19 and20).
The monitoring data also indicate leaching 1 m b.g.s. of a further 17 pesticides (or theirdegradation products), but often in low concentrations. Although the concentrationsdetected 1 m b.g.s. exceeded 0.1 �g/l in several samples, the average leachingconcentration (1 m b.g.s.) did not. This is summarized in Table 18, showing the numberof samples in which the various pesticides were detected on each site as well as themaximum concentration. Apart from slight leaching of ETU (Kjæret al.,2002) andamidosulfuron, within this group of 16 pesticides (or their degradation products)leaching from 1 meter was only observed at the loamy soil sites, where it was associatedwith pronounced macropore transport, resulting in very rapid movement of pesticidesthrough the vadose zone. It should be noted that the findings regarding amidosulfuronare of very limited use since the degradation products – with which the leaching risk isprobably mainly associated – are not included, as methods for their analysis are not yetavailable.Eleven of the 42 pesticides applied – about 26% – did not leach at all from 1 m b.g.s.during the monitoring period (Table 17). Four of the 11 were, however, detected in the
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groundwater monitoring screens (Table 19). The group of 11 includes the three differentsulfonylureas – metsulfuron-methyl, triasulfuron, iodosulfuron-methyl-sodium andtribenuron-methyl applied at several sites. For example, tribenuron-methyl was appliedat four different sites under different hydrological conditions, with percolation (1 mb.g.s.) during the first month after application ranging from 0 to 114 mm. Themonitoring results give no indication of leaching for any of the compounds or theirdegradation products. It should, however, be noted, that the leaching risk associatedwith an autumn application of tribenuron-methyl, where preferential transport is likelyto occur, has not yet been evaluated for the loamy soils.The leaching patterns of the sandy and loamy sites are further illustrated in Figure 40and 41, showing the frequency of detection in samples collected 1 m b.g.s. (suction cupson sandy soils and drainage systems on loamy soils) and the deeper located groundwatermonitoring screens.
Frequency of detection (%)0%Metribuzin-diketoPPUMetribuzin-desamino-diketoDesisopropylatrazinePPU-desaminoETU2-hydroxy-desethyl-terbuthylazineDesethylterbuthylazineMetribuzine2-hydroxy-terbuthylazineBentazone2-amino-N-isopropylbenzamidAzoxystrobinBromoxynilCGA 322704
Frequency of detection (%)80%100%
20%
40%
60%
0%
20%
40%
60%
80%
100%
A
B
TylstrupSuction cups
TylstrupGroundwater monitoring screens
PPUMetribuzin-diketoPPU-desaminoBentazoneAmidosulfuronDesethylterbuthylazineBifenox-acidBifenox2-amino-N-isopropylbenzamidPicolinafenAMPAPirimicarb-desmethylFenpropimorph4-chlor-2-methylphenolAzoxystrobin
C
D
JyndevadSuction cups
JyndevadGroundwater monitoring screens
>=0.1 �g/l
< 0.1 �g/l
>=0.1 �g/l
< 0.1 �g/l
Figure 40.Frequency of detection in samples from the suction cups (left) and groundwater monitoring screenslocated deeper than the suction cups (right) at the sandy soil sites:Tylstrup(A, B) andJyndevad(C, D). Frequencyis estimated for the entire monitoring period and the length of time that the different pesticides have been included inthe programme and the number of analysed samples thus varies considerably among the different pesticides. Thefigure only includes the fifteen most frequently detected pesticides. Pesticides monitored for less than two years areindicated by an asterisk and pesticides monitored for less than one year are not included.
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Frequency of detection (%)
Frequency of detection (%)
0%AMPADesethylterbuthylazineCyPMTerbuthylazine2-hydroxy-terbuthylazine2-hydroxy-desethyl-terbuthylazineGlyphosateTebuconazoleBifenox-acidBentazoneAzoxystrobinDesisopropylatrazinMetamitron-desaminoCL153815Metamitron
20%
40%
60%
80%
100%0%
20%
40%
60%
80%
100%
A
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EstrupDrainage system
EstrupGroundwater monitoring screens
DesethylterbuthylazineBifenox-acidAMPACyPMTerbuthylazineTFMPDesisopropylatrazineGlyphosateBentazone2-hydroxy-desethyl-terterbuthylazine2-hydroxy-terbuthylazinePropyzamidMetamitron-desaminoMetamitronRH24644
C
D
SilstrupDrainage system
SilstrupGroundwater monitoring screens
DesethylterbuthylazineTerbuthylazineBentazoneDesisopropylatrazine2-hydroxy-terbuthylazineMetamitron-desamino2-hydroxy-desethyl-terbuthylazineEthofumesatMetamitronFluazifop-P (free acid)TebuconazoleAMPAPirimicarb-desmethylPirimicarbPropyzamid
E
F
FaardrupDrainage system
FaardrupGroundwater monitoring screens
>=0.1 �g/l
< 0.1 �g/l
>=0.1 �g/l
< 0.1 �g/l
Figure 41.Frequency of detection in samples from the drainage system (left) and groundwater monitoring screenslocated deeper than the drainage system (right) at the loamy soil sites:Estrup(A, B),Silstrup(C, D), andFaardrup(E, F). Frequency is estimated for the entire monitoring period and the time that the different pesticides have beenincluded in the programme and the number of analysed samples thus varies considerably among the differentpesticides. The figure only includes the 15 most frequently detected pesticides. Pesticides monitored for less than twoyears are indicated by an asterisk and pesticides monitored for less than one year are not included.
On the sandy soils the number of leached pesticides as well as the frequency ofdetection was much lower than on loamy soils (Figure 40 and 41), the exceptions beingthe mobile and persistent degradation products of rimsulfuron and metribuzin,frequently found in both suction cups and groundwater monitoring wells. Thisdifference was mainly due to the different flow patterns characterising the two differentsoil types. On the sandy soils infiltrating water mainly passed through the matrix,thereby providing good conditions for sorption and degradation. Pesticides beingleached in the sandy soils were thus restricted to mobile as well as persistent pesticides.
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On the loamy soils pronounced macropore transport resulted in the pesticides movingvery rapidly through the unsaturated zone. Compared to the sandy soils residence timewas much lower on the structured, loamy soils. As a result of this, various types ofpesticides, even those being strongly sorbed, were prone to leaching on the loamy typesof soil.At the loamy sites pronounced leaching was generally confined to the depth of thedrainage system. Several pesticides were often detected in the drainage system, whereasthe frequency of detection in the monitoring screens situated beneath the drainagesystem was lower and varied considerably between the three sites (Figure 41). Thesedifferences should be seen in relation to the different sampling procedures applied.Frequent, integrated water samples can be provided from a drainage system thatcontinuously captures water infiltrating throughout the drainage runoff season.However, although the monitoring screens situated beneath the drainage systems weresampled less frequently (on a monthly basis from a limited number of the monitoringscreens (Appendix 2), pesticides were frequently found in selected screens at Faardrupand Silstrup. Hitherto, at the Estrup site, leaching of pesticides has mainly beenconfined to the depth of the drainage system. Apart from 39, 27 and 16 samplescontaining glyphosate, desisopropyl-atrazine, and bentazone respectively, pesticideshave only occasionally been detected in the screens beneath the drainage system(Appendix 5). The differences are, however, largely attributable to the hydrologicalconditions. Compared to the Silstrup and Faardrup sites, the C horizon (situated beneaththe drainage depth) at the Estrup site is less permeable with less preferential flowthrough macropores (se Kjæret al.2005c for details). The movement of water andsolute may therefore be slower at Estrup, allowing for dispersion, dilution, sorption anddegradation and thereby reducing the risk of transport to deeper soil layers. Anindication thereof are the long periods with groundwater table beyond drainage depth inwhich an increasing lateral transport to the drainage system and decreased leaching tothe deeper groundwater will occur.Comparing the loamy sites, the number of drainage water samples containingpesticides/degradation products was markedly higher at Silstrup and Estrup than atFaardrup, which is largely attributable to the differences in the hydrological conditions.The occurrence of precipitation and subsequent percolation within the first month afterapplication were, generally, higher at Silstrup and Estrup than at Faardrup (Table 9,Table 11, and Table 13).
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Allerup, P., and Madsen, H. (1979): Accuracy of point precipitation measurements.Danish Meteorological Institute,Climatological Papers No. 5,Copenhagen, 84 pp.Barlebo, H.C., Rosenbom, A., and Kjær, J. (2007): Evaluation of Pesticide Scenarios forthe Registration Procedure; no. 1178; Danish Environmental Protection Agency.Available on http://www2.mst.dk/common/Udgivramme/Frame.asp?http://www2.mst.dk/Udgiv/publications/2007/978-87-7052-540-/html/default_eng.htm.Boesten, J. J. T. I. (2000): From laboratory to field: uses and limitations of pesticidebehaviour models for the soil/plant system.Weed Res.,40, 123–138.Danish EPA (1997): Bekendtgørelse nr. 637 af 30. juni 1997, Miljø- ogEnergiministeriet 1997.EEC (1971): Directive 71/250/EEC of 15 June 1971 establishing Community methodsof analysis for the official control of feeding-stuffs,Official Journal L 155, 12/07/1971pp. 0013–0037.Information is also available on:http://www.seas.upenn.edu/courses/belab/LabProjects/1997/BE210S97R4R01.htmFunk, W., Dammann, V., and Donnevert, G. (1995): Quality assurance in analyticalchemistry, VCH Verlagsgesellschaft GmbH, Weinheim.Flerchinger, G.N., Seyfried, M.S. and Hardegree, S.P. (2006): Using soil freezingcharacteristics to model multi-season soil water dynamics. Vadose Zone Journal, 5,1143-1153.Juhler, R.K., Henriksen, T., Rosenbom, A.E., and Kjaer, J. (2010): Fate and transport ofchlormequat in subsurface environments.Environ. Sci. Pollut. Res.,17(6), 1245-1256.Kjær, J., Ullum, M., Olsen, P., Sjelborg, P., Helweg, A., Mogensen, B., Plauborg, F.,Jørgensen, J. O., Iversen, B. O., Fomsgaard, I., and Lindhardt, B. (2002): The DanishPesticide Leaching Assessment Programme: Monitoring results, May 1999–June 2001,Geological Survey of Denmark and Greenland, 2002.Kjær, J., Ullum, M., Olsen, P., Sjelborg, P., Helweg, A., Mogensen, B., Plauborg, F.,Grant, R., Fomsgaard, I., and Brüsch, W. (2003): The Danish Pesticide LeachingAssessment Programme: Monitoring results, May 1999–June 2002, Geological Surveyof Denmark and Greenland, 2003.Kjær, J., Olsen, P., Barlebo, H. C., Juhler, R. K., Plauborg, F., Grant, R., Gudmundsson,L., and Brüsch, W. (2004): The Danish Pesticide Leaching Assessment Programme:Monitoring results, May 1999–June 2003, Geological Survey of Denmark andGreenland, 2004.
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Kjær, J., Olsen, P., Ullum, M., and Grant, R. (2005a): Leaching of glyphosate andamino-methylphosphonic acid from Danish agricultural field sites,J. Environ. Qual.,34, 608–630.Kjær, J., Olsen, P., Henriksen, T. and Ullum, M. (2005b): Leaching of metribuzinmetabolites and the associated contamination of a sandy Danish aquifer,Environ. Sci.Technol.39, 8374-8381.Kjær, J., Olsen, P., Barlebo, H. C., Juhler, R. K., Henriksen, T., Plauborg, F., Grant, R.,Nyegaard P., and Gudmundsson L. (2005c): The Danish Pesticide Leaching AssessmentProgramme: Monitoring results, May 1999–June 2004, Geological Survey of Denmarkand Greenland, 2005.Kjær, J., Olsen, P., Barlebo, H. C., Henriksen T., Plauborg, F., Grant, R., Nyegaard P.Gudmundsson, L., and Rosenbom, A. (2007): The Danish Pesticide LeachingAssessment Programme: Monitoring results, May 1999–June 2006, Geological Surveyof Denmark and Greenland, 2007.Kjær, J., Rosenbom, A., Olsen, P., Juhler, R.K., Plauborg, F., Grant, R., Nyegaard, P,Gudmundsson, L., and Brüsch, W. (2008): The Danish pesticide Leaching AssessmentProgramme: Monitoring results May 1999 - June 2007. Geological Survey of Denmarkand Greenland. Copenhagen, 92 pp. + 6 Appendices.Kjær, J., Rosenbom, A., Olsen, P., Ernstsen, V., Plauborg, F., Grant, R., Nyegaard, P,Gudmundsson, L., and Brüsch, W. (2009): The Danish pesticide Leaching AssessmentProgramme: Monitoring results May 1999 - June 2008. Geological Survey of Denmarkand Greenland. Copenhagen, 85 pp. + 6 Appendices.Kördel, von W. (1997): Feldversuche zum Austrag von Pflanzenschutzmitteln überDrainage – Abschätzung der Belastung aquatischer Ökosysteme,Gesunde Pflanzen, 49(5): 163–170 (in German).Larsbo, M., Roulier, S., Stenemo, F., Kasteel, R., and Jarvis, N. (2005): An improveddual-permeability model of water flow and solute transport in the vadose zone.VadoseZone Journal4(2), 398-406.Lindhardt, B., Abildtrup, C., Vosgerau, H., Olsen, P., Torp, S., Iversen, B. V.,Jørgensen J. O., Plauborg, F., Rasmussen, P., and Gravesen, P. (2001): The DanishPesticide Leaching Assessment Programme: Site characterization and monitoringdesign, Geological Survey of Denmark and Greenland, 2001.Miller, J. N., and Miller, J. C. (2000): Statistics and chemometrics for analyticalchemistry, Pearson, Essex.Plantedirektoratet (2009): Vejledning om gødsknings- og harmoniregler. Planperioden1. august 2008 til 31. juli 2009. Ministeriet for Fødevare, Landbrug og Fiskeri.Revideretoktober2008.105pp.ISBN978-87-7083-238-0.(Web)http://www.netpublikationer.dk/FVM/9114/pdf/Vejledning_GR_HR_2008-09_rev_udg.pdf.
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Plantedirektoratet (2010): Vejledning om gødsknings- og harmoniregler. Planperioden1. august 2009 til 31. juli 2010. Ministeriet for Fødevarer, Landbrug og Fiskeri.Revideret udgave 14. September 2009. http://www.netpublikationer.dk/FVM/978-87-7083-418-6/index.htm.Topp, G.C., Davis, J.L. and Annan, A.P. (1980). Electromagnetic determination of soilwater content: Measurements in coaxial transmission lines. Water Resources Research,16, 574-582.Rosenbom, A.E., Kjær, J., Henriksen, T., Ullum, M., and Olsen, P. (2009): Ability ofthe MACRO Model to Predict Long-Term Leaching of Metribuzin andDiketometribuzin,Environ. Sci. Technol.,43(9), 3221-3226.Rosenbom, A.E., Kjær, J., and Olsen, P. (2010a): Long-term leaching of rimsulfurondegradation product through sandy agricultural soils,Chemosphere,79, 830-838.Rosenbom A., Brüsch, W. Juhler, R. K., Ernstsen, V., Gudmundsson, L., Plauborg, F.,Grant, R. and Olsen, P., (2010b): The Danish Pesticide Leaching AssessmentProgramme: Monitoring results May 1999 - June 2009. Geological Survey of Denmarkand Greenland. Copenhagen (available on www.pesticidvarsling.dk).Thorling, L. (ed.) (2010): Grundvand. Status og udvikling 1989-2008. GEUS 2010.ISBN978-87-7871-274-5.http://www.geus.dk/publications/grundvandsovervaagning/index.htm.U.S. Environmental Protection Agency (1998): Guidance for prospective groundwatermonitoring studies. Environmental Fate and Effects Division, Office of PesticidePrograms, U.S. Environmental Protection Agency, September 16, 1998.Wilson, A. L. (1970): The performance characteristics of analytical methods II,Talanta17(1), 31–44.
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Appendix 1. Chemical abstracts nomenclature for the pesticides encompassed by the PLAP
Table A1.1Systematic chemical nomenclature for the pesticides and degradation products encompassed by thePLAP.ParameterSystematic chemical nomenclatureAmidosulfuronN-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-amino]sulfonyl]-N-methylmethanesulfonamideAzoxystrobinMethyl (E)-2-{2-[(6-(2-cyanophenoxy)-4-pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate-CyPME-2-(2-[6-cyanophenoxy)-pyrimidin-4-yloxy]-phenyl) – 3-methoxyacrylic acidBentazone3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2 dioxide- AIBA2-amino-N-isopropyl-benzamidBromoxynil3,5-dibromo-4-hydroxybenzonitrileBifenoxmethyl 5-(2,4-dichlorophenoxy)-2-nitrobenzoate-Bifenox acid5-(2,4-dichlorophenoxy)-2-nitrobenzoic acid- Nitrofen2,4-dichlorophenyl 4'-nitrophenyl etherChlormequat2-chloroethyltrimethylammonium chlorideClomazone2-[(2-chlorphenyl)methyl]-4,4-dimethyl-3-isoxazolidione- FMC65317 (Propanamide-(N-[2- chlorophenol)methyl] -3-hydroxy-2,2- dimethyl propanamideclomazone)Clopyralid3,6-Dichloropyridine-2-carboxylic acidDesmediphamEthyl 3-(phenylcarbamoyloxy)phenylcarbamate- EHPCCarbamic acid, (3-hydroxyphenyl)-ethyl esterDimethoateO,O-dimethyl S-methylcarbamoylmethyl-phosphorodithioateEthofumesate(�)-2-ethoxy-2,3-dihydro-3,3-dimethylbenzofuran-5-yl-methanesulfonate2)- Fluazifop-P(R)-2-(4-((5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy-propanoic acid- TFMP2)5-trifluoromethyl-pyridin-2-olEpoxiconazole(2RS, 3SR)-1-(2-(2-chlorophenyl)-2,3-epoxy-2-(4-fluorophenyl)propyl)-1H-1,2,4-triazol1)- ETUEthylenethioureaFenpropimorphCis-4-[3-[4-(1,1-dimethylethyl)-phenyl]-2-methylpropyl]-2,6-imethylmorpholine- Fenpropimorphic acidCis-4-[3-[4-(2-carboxypropyl)-phenyl]-2-methylpropyl]-2,6-dimethylmorpholineFlamprop-M-isopropylIsopropyl N-benzoyl-N-(3-chloro-4-flourophenyl)-D-alaninate- Flamprop (free acid)N-benzoyl-N-(3-chloro-4-flourophenyl)-D-alanineFlorasulam2’,6’,8-Trifluoro-5-methoxy-s-triazolo [1,5-c]pyrimidine-2-sulfonanilide- Florasulam-desmethylN-(2,6-difluorophenyl)-8-fluro-5-hydroxy[1,2,4]triazolo[1,5-c]pyrimidine-2-sulfonamideFluroxypyr(4-amino-3,5-dichloro-6-fluro-2-pyridinyl)oxy]acetic acidGlyphosateN-(phosphonomethyl)glycine- AMPAAmino-methylphosphonic acidIodosulfuron-methyl-sodiumsodium salt of methyl 4-iodo-2-[[[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]amino]sulfonyl]benzoate- Triazinamine2-amino-4-methoxy-6-methyl-1,3,5-triazine- Metsulfuron-methylMethyl2-[[[[(4-methoxy-6-methyl-1,3,5-triazine-2-yl)amino]=carbonyl]amino]-sulfonyl]benzoic acidIoxynil4-hydroxy-3,5-diiodobenzonitrileLinuron3-(3,4-dichlorophenyl)-1-methoxy-1-methylureaMCPA(4-chloro-2-methylphenoxy)acetic acid- 4-chlor-2-methylphenol4-chlor-2-methylphenolMesosulfuron-methylMethyl 2-[3-(4,6-dimethoxypyrimidin-2-yl)ureidosulfonyl]-4-methanesulfonamidomethylbenzoateMetamitron4-amino-4,5-dihydro-3-methyl-6-phenyl-1,2,4-triazin-5-one- Metamitron-desamino4,5-dihydro-3-methyl-6-phenyl-1,2,4-triazine-5-oneMetribuzin4-amino-6-tert-butyl-4,5-dihydro-3-methylthio-1,2,4-triazine-5-one- Metribuzin-desamino6-(1,1-dimethylethyl)-3-(methylthio)- 1,2,4-triazin-5-(4H)-one- Metribuzin-desamino-diketo6-tert-butyl-4,5-dihydro-3-methylthio-1,2,4-triazine-3,5-dione- Metribuzin-diketo4-amino-6-tert-butyl-4,5-dihydro-1,2,4-triazine-3,5-dioneMetsulfuron-methylMethyl2-[[[[(4-methoxy-6-methyl-1,3,5-triazine-2-yl)amino]=carbonyl]amino]-sulfonyl]benzoic acid- MesosulfuronPendimethalinPhenmedipham- MHPC-3-aminophenol- PHCP3)2-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]-4-[[(methylsulfonyl)amino]methyl]benzoic acidN-(1-ethyl)-2,6-dinitro-3,4-xynile3-[(methoxycarbonyl)amino]phenyl (3-methylphenyl)carbamateMethyl-N-(3-hydoxyphenyl)-carbamate1-amino-3-hydroxybenzene3-phenyl-4-hydroxy-6-chloropyridazine
A1-1
Appendix 1. Chemical abstracts nomenclature for the pesticides encompassed by the PLAP
Table A1.1 (continued)Systematic chemical nomenclature for the pesticides and degradation products encompassedby the PLAP.ParameterSystematic chemical nomenclaturePicolinafen4'-fluoro-6-(α,α,α-trifluoro-m-tolyloxy)pyridine-2-carboxanilide- CL1538156-(3-trifluoromethylphenoxy)-2-pyridine carboxylic acidPirimicarb2-(dimethylamino)-5,6-dimethyl-4-pyrimidinyldimethylcarbamate- Pirimicarb-desmethyl2-(dimethylamino)-5,6-dimethyl-4-pyrimidinylmethylcarbamate- Pirimicarb-desmethyl-2-methylformamido-5,6-dimethylpyrimidine-4-yl dimethylcarbamateformamidoPropiconazole1-[[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl]methyl]-1H-1,2,4-triazolePropyzamide3,5-dichloro-N-(1,1-dimethylprop-2-ynyl)benzamide- RH-246442-(3,5-dichlorophenyl)-4,4-dimethyl-5-methylene-oxalzoline- RH-24580N-(1,1-dimethylacetonyl)-3,5-dichlorobenzamide- RH-246553,5-dichloro-N-(1,1-dimethylpropenyl)benzamideProsulfocarbN-[[3-(4-methoxy-6-methyl-1,3,5-triazin-2-yl)-3-[2-(3,3,3,-trifluro=propyl)phenylsulfonyl]ureaRimsulfuronN-[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-3-(ethylsulfonyl)-2-pyridinesulfonamide- PPUN-(4,6-dimethoxy-2-pyrimidinyl-N-((3-ethylsulfonyl)-2-pyridinyl)urea (IN70941)- PPU-desaminoN-((3-(ethylsulfonyl)-2-pyridyl)-4,6 dimethoxy-2 pyrimidinamine (IN70942)Terbuthylazine6-chloro-N-(1,1-dimethylethyl)-N-ethyl-1,3,5,triazine-2,4-diamine- Desethyl-terbuthylazine6-chloro-N-(1,1-dimethylethyl)-1,3,5,triazine-2,4-diamine- Desisopropyl-atrazine6-chloro-N-ethyl-1,3,5,triazine-2,4-diamine- 2-hydroxy-desethyl-6-hydroxy-N-(1,1-dimethylethyl)-1,3,5,triazine-2,4-diamineterbuthylazine- 2-hydroxy-terbuthylazine6-hydroxy-N-(1,1-dimethylethyl)-N´-ethyl-1,3,5,triazine-2,4-diamineTebuconazolea-[2-(4-chlorophenyl)ethyl]-a-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanolThiamethoxam3-(2-cholro-thiazol-5-ylmethyl)-5-methyl[1,3,5]oxadiazinan-4ylidene-N-nitroamine- CGA 322704[C(E)]-N-[(2-chloro-5-thiazolyl)methyl]-N'-methyl-N'-nitroguanidine4)- Triazinamin-methyl4-methoxy-6-methyl-1,3,5-triazin-methylamineTriflusulfuronmethyl 2-[4-dimethylamino-6-(2,2,2-trifluoroethoxy)-1,3,5-triazin-2-ylcarbamoylsulfamoyl]-m-toluate- IN-E7710N-methyl-6-(2,2,2-trifluoroethoxy)-1,3,5-triazine-2,4-diamine- IN-D8526N,N-dimethyl-6-(2,2,2-trifluoroethoxy)-1,3,5-triazine-2,4-diamine- IN-M72226-(2,2,2-trifluoroethoxy)-1,3,5-triazine-2,4-diamineTriasulfuron1-[2-(2-chloroethoxy)phenylsulfonyl]-2-(4-methoxy-6-methyl-1,3,5-triazine-2-yl)-urea1)Degradation product of mancozeb.2)Degradation product of fluazifop-P-butyl.3)Degradation product of pyridate.4)Degradation product of Tribenuron-methyl.
A1-2
Appendix 2. Pesticide monitoring programme - Sampling procedure
From each of the PLAP sites, samples were collected of groundwater, drainage waterand soil water in the unsaturated zone. A full description of the monitoring design andsampling procedure is provided in Lindhardtet al.(2001) and Kjæret al.(2003),respectively.Until March 2002, pesticide analysis was performed monthly on water samples from thesuction cups located both 1 m b.g.s. and 2 m b.g.s., from two screens of the horizontalmonitoring wells and from two of the downstream vertical monitoring wells. Inaddition, more intensive monitoring encompassing all four groups of suction cups, sixscreens of the horizontal monitoring wells and five monitoring wells was performedevery four months (Kjæret al.,2002). At the loamy sites, the pesticide analysis was alsoperformed on drainage water samples.The monitoring programme was revised in March 2002 and the number of pesticideanalyses was reduced. At the loamy sites, pesticide analysis of water sampled from thesuction cups was ceased, and the monthly monitoring was restricted to just onemonitoring well. At Jyndevad, pesticide analysis of the suction cups located 2 m b.g.s.was ceased and the interval for the intensive monitoring encompassing the largernumber of monitoring screens was extended to six months, except for the suction cups 2m b.g.s. at Tylstrup, where the four-month interval was retained (Kjæret al.,2003).On the sandy soils, the analysis of a number of pesticides in water from the monitoringwells had to be further reduced, due to economical constraints imposed by the highprices on pesticide analysis. This reduction was based on results from the suction cupsimplying that leaching risk of certain pesticides was negligible, why analysis of alimited number of groundwater samples would be reasonable (see Table A5.1 and TableA5.2 in Appendix 5).In March 2008, a new revision of the monitoring programme was completed resulting inan optimization of the programme including an additional reduction in the samplingprogramme (Table A2.1). On the loamy sites, sampling from the suction cups forinorganic analysis, from one-two monitoring wells per site, and one horizontal well atSilstrup (H2) and Faardrup (H1) was suspended. On the sandy sites, only sampling fromthe monitoring well M6 at Tylstrup has been suspended (see Rosenbomet al.,2010b fordetails).Table A2.1.Pesticide monitoring programme in suction cups (S), horizontal monitoring wells (H) and verticalmonitoring wells (M) as of March 2009. Water sampling places (S, H, and M) from where sampling stopped in 2008and 2009 are given in bold. Well M10 at Silstrup was included in the programme on 5 February 2009.SiteMonthly monitoring Half-yearly monitoringNot(Intensive)(Extensive)Monitored*TylstrupM4, M5, S1a, S2aM1, M3, M4, M5, S1a , S2a, S1b , M2,M6,M7S2b*Jyndevad M1, M4, S1a, S2aM1, M2, M4, M5, M7, S1a, S2aM3,M6,S1b, S2bSilstrupM5, H1.2M5, M9, M10, M12, H1.1, H1.2, H1.3 M1, M2, M4,M6,M8, M7,M11,M13,H2.1, H2.2, H2.3EstrupM4, H1.2M1, M4, M5, M6, H1.1, H1.2, H1.3M2,M3, M7,Faardrup M4, M5, H2.3M4, M5, M6, H2.1, H2.3, H2.5M1,M2, M3, M7, H1.1,H1.2,H1.3S1a and S1b refer to suction cups installed 1 and 2 m b.g.s., respectively, at location S1, whereas S2a and S2b referto suction cups installed 1 and 2 m b.g.s., respectively, at location S2.*At Tylstrup suctions cups installed 2m b.g.sare monitored four times a year(see text).
A2-1
Appendix 2. Pesticide monitoring programme - Sampling procedure
Until July 2004, pesticide analyses were performed weekly on water sampled time-proportionally from the drainage system. Moreover, during storm events additionalsamples (sampled flow-proportionally over 1–2 days) were also analysed for pesticides.In June 2004 the drainage monitoring programme was revised. From July 2004 andonwards pesticide analyses were done weekly on water sampled flow- proportionallyfrom the drainage water system. See Kjæret al.2003 for further details on the methodsof flow-proportional sampling. The weighted average concentration of pesticides in thedrainage water was calculated according to the following equation:C=
∑Mi=1n
n
i
∑Vi=1
i
Mi=Ci¶Vi
where:n = Number of weeks within the period of continuous drainage runoff.Vi= Weekly accumulated drainage runoff (mm/week).Ci= Pesticide concentration collected by means of the flow-proportional sampler (�g/l).Until July 2004 where both time and flow-proportional sampling was applied thenumbers were:Mi=Cti¶ViIf no flow event occurs within the i'th weekMi=Cfi¶VfiIf a flow event occurs within the i'th week and if Cfi¶Vfi> Cti¶Viwhere:n = Number of weeks within the period of continuous drainage runoff.Vi= Weekly accumulated drainage runoff (mm/week).Vfi= Drainage runoff accumulated during a “flow event” (mm/storm event).Cfi= Pesticide concentration in the “event samples” collected by means of the flow-proportional sampler (�g/l).Cti= Pesticide concentration in the weekly samples collected by means of the time-proportional sampler (�g/l).Tables 9, 11, and 13 report the weighted average leachate concentration in the drainagewater within the first drainage season after application. In these tables this calculationperiod is defined as the period from the date of application until 1 July the followingyear, as pesticides are usually present in the first drainage runoff occurring afterapplication of pesticide.On the sandy soils the weighted average concentration of pesticides leached to thesuction cups situated 1 m b.g.s. was estimated using the measured pesticideconcentration and estimated percolation on a monthly basis. Pesticide concentrationsmeasured in suction cups S1 and S2 were assumed to be representative for each sampleperiod. Moreover, accumulated percolation rates deriving from the MACRO modelwere assumed to be representative for both suction cups S1 and S2. For each of themeasured concentrations, the corresponding percolation (Perc.) was estimated accordingto the equation:
A2-2
Appendix 2. Pesticide monitoring programme - Sampling procedure
Pi=
∑
t2t1
Pt
wheret = sampling date; t1= 0.5(ti-1+ti) ; t2=0.5(ti+ti+1)Pt= daily percolation at 1 m b.g.s. as estimated by the MACRO model (mm)The average concentration was estimated according to the equation:C=
∑C¶P∑Pii
i
whereCi= measured pesticide concentration in the suction cups located 1 m b.g.s.Tables 3 and 6 report the weighted average leachate concentration. In these tables thiscalculation period is defined as the period from the date of first detection until 1 July thefollowing year. On sandy soils the transport of pesticides down to the suction cupssituated at 1 m depth may take some time. In most cases the first detection of pesticidesoccurs around 1 July, why the reported concentration represents the yearly averageconcentration. In a few cases the first detection of pesticides occurs later, but this lateroccurrence does not affect the weighted average calculation. E.g. the reported averageconcentration using a calculation period from the first detection until 1 July thefollowing year is equal to that using a calculation period of a year (1 July – 30 June) thefollowing year). Unless noted the concentrations listed in Tables 3 and 6 can thereforebe considered as yearly average concentrations. In the few cases where reportedconcentrations are either not representative for an annual average concentration or notrepresentative for the given leaching pattern (leaching increases the second or third yearafter application) a note is inserted in the table.
A2-3
Appendix 2. Pesticide monitoring programme - Sampling procedure
A2-4
Appendix 3. Agricultural management
Table A3.1Management practice atTylstrupduring the 2007 to 2010 growing seasons. The active ingredients of thevarious pesticides are indicated in parentheses.DateManagement practice09.02.0727.03.0708.06.0701.08.0703.08.0707.09.0712.09.0712.09.0718.10.0716.11.0722.05.0829.05.0805.06.0813.06.0817.06.0818.08.0831.08.0810.04.0910.04.0914.04.0915.05.0923.06.0929.06.0908.07.0908.07.0920.08.0928.08.0904.04.1026.04.1004.05.1006.05.1017.05.1026.05.1008.06.1015.06.1024.06.1001.07.10Herbicide - 1.0 l/ha Kerb 500 SC (propyzamide)Herbicide - 0.8 l/ha Matrigon (clopyralid)Irrigation 30 mmDirect harvest and simultaneous shredding of straw (seed yield 24.5 hkg/ha 91% DM, straw yield)Rotary cultivated - depth 3.0 cm (straw incorporation)Rotary cultivated - depth 7.0 cm (straw incorporation)Ploughed - 22 cm depthWinter wheat sown - cv. Smuggler.Herbicide - 5.0 l/ha Stomp (pendimethalin)Herbicide - 1.0 l/ha Folicur EC250 (tebuconazole)Irrigation - 32 mmIrrigation - 32 mmIrrigation - 32 mmIrrigation - 30 mmFungicide – 1.0 l/ha Amistar (azoxystrobin)Winter wheat harvested (seed yield 92.1 hkg/ha 85% DM)Straw yield (18.5 hkg/ha 100% DM)Ploughed - 24 cm depthRolled with a concrete rollerSpring barley sown - cv. KeopsHerbicide - 1.5 l/ha Basagran M75 (bentazone + MCPA)Fungicide - 1.0 l/ha Amistar (azoxystrobin) – fungiIrrigation - 26 mmMavrik (tau-fluvalinate) - pests - 0.1 l/ha (not analysed)Irrigation – 27 mmHarvest of spring barley. Grain yield 53.4 hkg/ha, 85% DMStraw removed, yield 17.4 hkg/ha 100% DMPloughed - 24 cm depthRolled with concrete rollerSeedbed preparation - 10 cm depthPlanting of potatoes - cv. KurasRidgingHerbicides - 1.0 l/ha Fenix (aclonifen) + 10 g/ha Titus WSB (rimsulfuron)Herbicide - 20 g/ha Titus WSB (rimsulfuron)Fungicide - 0.2 l/ha Ranman (cyazofamid)Fungicide - 0.2 l/ha Ranman (cyazofamid)Fungicide - 0.2 l/ha Ranman (cyazofamid)
A3-1
Appendix 3. Agricultural management
Table A3.2Management practice atJyndevadduring the 2007 to 2010 growing seasons. The active ingredients ofthe various pesticides are indicated in parentheses.DateManagement practice13.04.0727.04.0707.05.0705.06.0707.08.0713.09.0728.09.0729.09.0701.10.0729.10.0703.12.0707.05.0814.05.0821.05.0830.05.0805.06.0811.06.0825.06.0808.07.0830.08.0817.03.0918.03.0918.03.0927.04.0911.05.0926.05.0927.05.0905.06.0929.06.0907.08.0914.04.1015.04.1022.04.1004.05.1004.05.1027.05.1008.06.1024.06.1028.06.1030.06.10Plant growth inhibitor – 1.0 l/ha Cycocel 750 (Chlormequat-chloride)Irrigation - 27 mmHerbicide - 1.0 l/ha Opus (epoxiconazole)Irrigation - 27 mmHarvest of triticale (seed yield 38.7 hkg/ha 85% DM, straw yield 38.3 hkg/ha 100% DM)Herbicide - 2.0 l/ha Roundup (glyphosate, not monitored)Ploughed - 22 cm depthRolled with a concrete rollerWinter wheat sown – cv. AmbitionHerbicide - 0.133 g/ha Pico 750 WG (picolinafen)Fungicide - 1.0 l/ha Folicur EC 250 (tebuconazole)Irrigation - 42 mmIrrigation - 27 mmIrrigation - 27 mmIrrigation - 30 mmIrrigation - 35 mmFungicide - 1.0 l/ha Amistar (azoxystrobin)Irrigation - 35 mmIrrigation - 30 mmWinter wheat harvested (seed yield 68.1 hkg/ha 85% DM, straw yield 28.1 hkg/ha 100% DM)Ploughed - 22 cm depthRolled with a concrete rollerSpring barley sown cv. SimbaHerbicide - 1.2 l/ha Fox 480 SC (bifenox)Herbicide - 1.5 l/ha Basagran M75 (bentazone+ MCPA )Fungicide - 1.5 l/ha Bell (boscalide + epoxiconazole)Irrigation - 30 mmIrrigation - 27 mmIrrigation - 27 mmHarvest of spring barley. Grain yield 64.0 hkg/ha 85% DM, straw yield 19.5 hkg/ha 100% DMPloughed. Depth 24 cmRolled with concrete rollerSeedbed preparation - 9 cm depthPlanting of potatoes - cv. KurasRidgingHerbicides - 1.0 l/ha Fenix (aclonifen) + 10 g/ha Titus WSB (rimsulfuron)Herbicide - 20 g/ha Titus WSB (rimsulfuron)Irrigation - 25 mmFungicide - 0.2 l/ha Ranman (cyazofamid)Irrigation - 25 mm
A3-2
Appendix 3. Agricultural management
Table A3.3Management practice atSilstrupduring the 2007 to 2010 growing seasons. The active ingredients of thevarious pesticides are indicated in parentheses.DateManagement practice13.04.07Herbicide - 100 ml/ha Hussar OD (iodosulfuron)13.04.07Growth retardant - 1.2 l/ha Cycocel 750 (chlormequat-chloride)07.06.07Fungicide - 1.0 l/ha Opus (epoxiconazole)24.08.07Winter wheat harvested (seed yield 100.7 hkg/ha 85% DM, straw yield 40.8 hkg/ha 100% DM,shredded at harvest29.08.07Stubble harrowed, heavy disk harrow (Dalbo) - 5 cm depth12.11.07Ploughed - 27 cm depth07.05.08Fodder beet sown - cv. Kyros22.05.08Herbicide - 30 g/ha Safari (triflusulfuron) + 0.5 l/ha Goliath (metamitron) + 1.5 l/ha Betanal(phenmedipham)30.05.08Herbicide - 30 g/ha Safari (triflusulfuron) + 0.5 l/ha Goliath (metamitron) + 1.5 l/ha Betanal(phenmedipham) + 0.07 l/ha Tramat 500 SC (ethofumesate)17.06.08Herbicide - 30 g/ha Safari (triflusulfuron) + 0.5 l/ha Goliath (metamitron) + 1.5 l/ha Betanal(phenmedipham) + 0.07 l/ha Tramat 500 SC (ethofumesate)26.06.08Insecticide - 0.30kg/ha Pirimor G (pirimicarb)01.07.08Herbicide - 3.0 l/ha Fusilade Max (fluazifop-P-butyl)04.07.08Herbicide - 30 g/ha Safari (triflusulfuron) + 0.5 l/ha Goliath (metamitron) + 1.5 l/ha Betanal(phenmedipham)09.07.08Insecticide - 0.300 kg/ha Pirimor G (pirimicarb)27.10.08Fodder beet harvested. Yield of root 17.3 t/ha 100% DM, yield of top 5.15 t/ha 100% DM15.12.08Ploughed - 23 cm depth02.04.09Tracer - 31.5 kg/ha potassium bromide11.04.09Rolled with Cambridge roller11.04.09Spring barley sown - cv. Keops; undersown red fescue cv. Jasperina19.05.09Herbicide -1.25 l/ha Fighter 480 (bentazone)24.06.09Fungicide - 1.0 l/ha Amistar (azoxystrobin)16.07.09Wholecrop harvest of spring barley - 94.6 hkg/ha 100% DM24.08.09Herbicide - 0.020 l/ha Hussar OD (iodosulfuron)09.09.09Herbicide - 1.5 l/ha Fox 480 SC (bifenox)02.05.10Herbicide - 1.5 l/ha Fusilade Max (fluazifop-P-butyl)05.05.10Herbicides - 0.1 l/ha Hussar OD (iodosulfuron) + 0.7 l/ha SweDane MCPA 750 (not analyzed)
A3-3
Appendix 3. Agricultural management
Table A3.4Management practice atEstrupduring the 2007 to 2010 growing seasons. The active ingredients of thevarious pesticides are indicated in parentheses.DateManagement practice11.04.0731.05.0707.08.0708.08.0714.09.0702.10.0703.10.0730.10.0722.11.0713.06.0816.08.0816.08.0812.03.0906.04.0908.04.0908.04.0901.05.0914.05.0904.06.0907.08.0907.08.0924.08.0924.08.0924.08.0925.08.0930.09.0909.10.0920.04.1010.05.10Growth retardant - 1.2 l/ha Cycocel 750 (chlormequat-chloride)Fungicide - 1.0 l/ha Opus (epoxiconazole)Winter wheat harvested (seed yield 81.5 hkg/ha, 85% DM)Straw shredded (47.4 hkg/ha, 100% DM)Herbicide - 1.5 l/ha Roundup Max (glyphosate)Ploughed - depth 20 cm (packed with a ring roller)Winter wheat sown – cv. Frument.Herbicide - 0.133 g/ha Pico 750 WG (picolinafen)Fungicide - 1.0 l/ha Folicur EC 250 (tebuconazole)Fungicide - 1.0 Amistar (azoxystrobin)Winter wheat harvested (seed yield 83.8 hkg/ha 85% DM)Straw shredded - 40.7 hkg/ha 100% DMPloughed - depth 18 cm - packed with a ring rollerTracer - 30 kg/ha potassium bromideSpring barley sown - cv. KeopsRolled with a cambridge rollerHerbicide - 1.2 l/ha Fox 480 SC (bifenox)Herbicide - 1.5 l/ha Basagran M75 (bentazone/MCPA)Fungicide - 1.0 l/ha Amistar (azoxystrobin)Spring barley harvested. Grain yield 71.4 hkg/ha, 85% DMStraw shredded. 39.9 hkg/ha, 100% DMPloughed - 20 cm depth - packed with a ring rollerRotor harrowed - 4 cm depthWinter rape sown - cv. CabernetHerbicide - 0.33 l/ha Command CS (clomazone)Herbicide - 0.75 l/ha Fox 480 SC (bifenox)Insecticide - 0.15 l/ha Cyperb (cypermethrin) (not analysed)Field partially resown with spring rape - cv. PlutoInsecticide - 0.3 l/ha Biscay OD 240 (thiacloprid)
A3-4
Appendix 3. Agricultural management
Table A3.5Management practice atFaardrupduring the 2007 to 2010 growing seasons. The active ingredients ofthe various pesticides are indicated in parentheses.DateManagement practice10.08.0722.08.0718.09.0718.09.0709.10.0720.11.0720.08.0826.08.0801.12.0805.04.0924.04.0930.04.0911.05.0914.05.0917.06.0906.10.0901.11.0907.04.1022.04.1001.06.10Stubble cultivation - 15 cm depthStubble cultivation - 15 cm depthPloughed and packed - 25 cm depthWinter wheat sown – cv. AmbitionHerbicide - 5.0 l/ha Stomp (pendimethalin)Fungicide - 1.0 l/ha Folicur 250 (tebuconazole)Winter wheat harvested (seed yield 89.6 hkg 85% DM, straw yield 65.2 hkg/ha 100% DM)Tracer - 30 kg/ha potassium bromidePloughing - 23 cm depthSugar beet sown - cv. PalaceHerbicide - 1.5 l/ha Betanal (phenmedipham) + 1.0 l/ha Goliath (metamitron)Herbicide - 10 g/ha Safari (triflusulfuron) + 1.5 l/ha Betanal (phenmedipham) + 1.0 l/ha GoliathHerbicide - 10 g/ha Safari (triflusulfuron) + 1.5 l/ha Betanal (phenmedipham) + 1.0 l/ha GoliathHerbicide - 1.0 l/ha Focus Ultra (cycloxydim)Herbicide - 1.0 l/ha Focus Ultra (cycloxydim)Harvest of sugar beet. Root yield 147.9 hkg/ha 100% DM, top yield 40.1 hkg/ha 100% DMPloughing - 20 cm depthSeedbed preparation - 6 cm depthSpring barley sown - mixture of varieties. Undersown red fescue – cv. MaximumHerbicide - 1.25 l/ha Fighter 480 (bentazone)
A3-5
Appendix 3. Agricultural management
A3-6
Appendix 4. Precipitation data for the PLAP sites
Figure A4.1.Monthly precipitation at all localities for the monitoring period July 2000 – June 2010. Normal values(1961 – 1990) are included for comparison.
A4-1
Appendix 4. Precipitation data for the PLAP sites
A4-2
Appendix 5. Pesticide detections in samples from drainage system, suction cups and monitoring wells
Table A5.1Number of samples where pesticides were either not detected (n.d.), detected in concentrations below 0.1 �g/l(det<0.1 �g/l) or detected in concentrations above 0.1 �g/l (det>=0.1�g/l) atTylstrup.Numbers are accumulated for theentire monitoring period, and pesticides monitored for less than one year are not included.
n.d.AIBA2-hydroxy-desethyl-terbuthylazine2-hydroxy-terbuthylazinAzoxystrobinBentazoneBromoxynilCGA 322704ClomazoneClopyralid*CyPMDesethyl-terbuthylazineDesisopropyl-atrazineDimethoateEpoxiconazoleETUFenpropimorphFenpropimorph-acidFlamprop-M (free acid)Flamprop-M-isopropylFluazifop-P (free acid)FluroxypyrFMC65317PPUPPU-desaminoIoxynilLinuronMetribuzinMetribuzin-desaminoMetribuzin-desamino-diketoMetribuzin-diketoPendimethalinPirimicarbPirimicarb-desmethylPirimicarb-desmethyl-formamidoPropiconazolePropyzamideRH24580RH24644RH24655RimsulfuronTebuconazoleTerbuthylazineTFMPThiamethoxamTriasulfuronTriazinaminTriazinamin-methyl1911901911632771921752246163191190176199198307276176176178194208507509198270386365289714302952951673072212212211571781951793175295285440
Vertical screensdet.<0.1det.>=0.1�g/l�g/l1
n.d.7267716710872648263677055657437897365656570747015772678985168731448281528982828258657772648275137
Suction cupsdet.<0.1det.>=0.1�g/l�g/l511
1
217
2
7
2
11935
3
12311365317
2301795163
1
*Number of analysed samples collected from the monitoring wells was reduced (see Appendix 2 for explanation).
A6-1
Appendix 5. Pesticide detections in samples from drainage system, suction cups and monitoring wells
Table A5.2Number of samples where pesticides were either not detected (n.d), detected in concentrations below 0.1 �g/l(det<0.1 �g/l) or detected in concentrations above 0.1 �g/l (det>=0.1�g/l) atJyndevad.Numbers are accumulated for theentire monitoring period, and pesticides monitored for less than one year are not included.
n.d.AIBA4-chlor-2-methylphenolAmidosulfuronAMPAAzoxystrobinBentazoneBifenoxBifenox acidBromoxynilCL153815*Chlormequat*CyPMDesethyl-terbuthylazineDesmethyl-amidosulfuronDimethoateEpoxiconazoleFenpropimorphFenpropimorph-acidFlamprop-M (free acid)Flamprop-M-isopropylFlorasulamFlorasulam-desmethylFluazifop-P (free acid)FluroxypyrGlyphosatePPUPPU-desaminoIoxynilMCPAMesosulfuron*Mesosulfuron-methylMetribuzinMetribuzin-desaminoMetribuzin-desamino-diketoMetribuzin-diketoNitrofenPendimethalinPHCPPicolinafen*PirimicarbPirimicarb-desmethylPirimicarb-desmethyl-formamidoPropiconazolePyridateRimsulfuronTebuconazoleTerbuthylazineTFMPTriazinamin-methyl17818988221233377984821835142334728816932324625912121911901932234026162181891228526266100257184352512512512301161682132393247
Vertical screensdet.<0.1det.>=0.1�g/l�g/l
n.d.45522068656828116136286512823489076794454285155693710261524578646330715935696869733948587577
Suction cupsdet.<0.1det.>=0.1�g/l�g/l2213421
2
51
2
24
18
11
1
28271
2
9985
554
77
1319
3
11
1
*Number of analysed samples collected from the monitoring wells was reduced (see Appendix 2 for explanation).
A6-2
Appendix 5. Pesticide detections in samples from drainage system, suction cups and monitoring wells
Table A5.3Number of samples where pesticides were either not detected (n.d), detected in concentrations below 0.1 �g/l(det<0.1 �g/l) or detected in concentrations above 0.1 �g/l (det>=0.1�g/l) atSilstrup.Numbers are accumulated for theentire monitoring period, and pesticides monitored for less than one year are not included.
Drainagen.d.detdet<0.1 �g/l >=0.1�g/lAIBA2-hydroxy-desethyl-terbuthylazine2-hydroxy-terbuthylazin3-aminophenol4-chlor-2-methylphenolAMPAAzoxystrobinBentazoneBifenoxBifenox acidClopyralidChlormequatCyPMDesethyl-terbuthylazineDesisopropyl-atrazineDesmediphamDimethoateEHPCEpoxiconazoleEthofumesateFenpropimorphFenpropimorph-acidFlamprop-M (free acid)Flamprop-M-isopropylFluazifop-P (free acid)FluroxypyrGlyphosateIN-D8526IN-E7710IN-M7222Iodosulfuron-methyl-MCPAMetamitronMetamitron-desaminoMetsulfuron methylMHPCNitrofenPendimethalinPHCPPhenmediphamPirimicarbPirimicarb-desmethylPirimicarb-desmethyl-formamidoPropiconazolePropyzamideProsulfocarbRH24580RH24644RH24655TerbuthylazineTFMPTriazinaminTriazinamin-methylTriflusulfuron644345535125555914144202482810181683611982817370106507933283352511038852100149062101160173141764369645166311141823327261071040115964431
HorizontalVertical screensn.d. det detn.d. det det<0.1 >=0.1<0.1 >=0.1�g/l �g/l�g/l �g/l7484847066123911171611633612010184107736262162747474731337412856565578661541587810616121661082092091597475787877781074272745613115115217012422616821327231186622311314824014711811733914814714814828314223210210210214912332331814923432223109240433436308148143147149148149173571351481021
Suction cupsn.d. detdet<0.1 >=0.1�g/l�g/l
361017411912743171258272035427272627568328
155135441
58183211214
141711525
1
115
11
4
1103
2743114
43
3
1723
21
404055
915
94
41416174215514
2
83
45959592027
61
211510
1
513029
1
917
1927
A6-3
Appendix 5. Pesticide detections in samples from drainage system, suction cups and monitoring wells
Table A5.4Number of samples where pesticides were either not detected (n.d), detected in concentrations below 0.1 �g/l(det<0.1 �g/l) or detected in concentrations above 0.1 �g/l (det>=0.1�g/l) atEstrup.Numbers are accumulated for the entiremonitoring period, and pesticides monitored for less than one year are not included.
AIBA2-hydroxy-desethyl-terbuthylazine2-hydroxy-terbuthylazine4-chlor-2-methylphenolAmidosulfuronAMPAAzoxystrobinBentazoneBifenoxBifenox acidBromoxynilCL153815ClopyralidChlormequatCyPMDesethyl-terbuthylazineDesisopropyl-atrazineDimethoateEpoxiconazoleEthofumesateFenpropimorphFenpropimorph-acidFlamprop-M (free acid)Flamprop-M-isopropylFlorasulamFlorasulam-desmethylFluroxypyrGlyphosateIoxynilMCPAMesosulfuronMesosulfuron-methylMetamitronMetamitron-desaminoMetsulfuron methylNitrofenPicolinafenPirimicarbPirimicarb-desmethylPirimicarb-desmethyl-formamidoPropiconazoleTebuconazoleTerbuthylazineTriazinaminTriazinamin-methyl
HorizontalVertical screensscreensn.d. detdet n.d. detdet n.d. detdet<0.1 >=0.1<0.1 >=0.1<0.1 >=0.1�g/l �g/l�g/l �g/l�g/l�g/l23517912714443101984411816923121354914434188988359182821181119180871491189173618176130266315919119819239491251617012588513323120110010870112711320251750503434158961071918414018925962421946393455553530341554134242746465519406766768639635218018011210954632340850511251185631923219715969158150124208208125100120514125111839915815720850118225223261309118222195
Drainage
Suction cupsn.d. det<0.1�g/l5det>=0.1�g/l
98151218211
115
711
23322
3
8437128
471
52623
23172323
1162149132738
28962
2
1341
3
233
1511
22
1
1739
1
66523222
13222476
1331735
2311
A6-4
Appendix 5. Pesticide detections in samples from drainage system, suction cups and monitoring wells
Table A5.5Number of samples where pesticides were either not detected (n.d), detected in concentrations below 0.1 �g/l(det<0.1 �g/l) or detected in concentrations above 0.1 �g/l (det>=0.1�g/l) atFaardrup.Numbers are accumulated for theentire monitoring period, and pesticides monitored for less than one year are not included.
Drainagen.d.detdet<0.1 >=0.1�g/l�g/l68161719020114311319110760126101688411034228278624199778381114767070761701914499155184113742727279911421111593111115971155299113794697314770227974704731504703011687727
AIBA2-hydroxy-desethyl-2-hydroxy-terbuthylazine4-chlor-2-methylphenolAMPAAzoxystrobinBentazoneBromoxynilCGA 322704ClomazoneCyPMDesethyl-terbuthylazineDesisopropyl-atrazineDesmediphamDimethoateEHPCEpoxiconazoleEthofumesateFenpropimorphFenpropimorph-acidFlamprop-M (free acid)Flamprop-M-isopropylFluazifop-P (free acid)Fluazifop-P-butylFluroxypyrFMC65317GlyphosateIN-D8526IN-E7710IN-M7222IoxynilMCPAMetamitronMetamitron-desaminoMHPCPendimethalinPhenmediphamPirimicarbPirimicarb-desmethylPirimicarb-desmethyl-PropiconazolePropyzamideProsulfocarbRH24580RH24644RH24655TebuconazoleTerbuthylazineTFMPThiamethoxamTriazinamin-methylTriflusulfuron
Horizontalscreensn.d. detdet<0.1 >=0.1�g/l�g/l616018541091109262318158699268215732665852669058159585666661281691091242424811099090665566906666116681616969695383511585724
Vertical screensn.d.
Suction cupsdet>=0.1�g/l
detdet n.d. det<0.1 >=0.1<0.1�g/l �g/l�g/l63024373575
132126164254282194136225126166194149166165148123143188156156148142159165305166282545454224255195171163125163243162163303155126155155155120149212614754
1428
312916
24
7
275454
2
5
1
26295561
3
2
1
11936122321512
732929292952292954
124
21
A6-5
Appendix 5. Pesticide detections in samples from drainage system, suction cups and monitoring wells
A6-6
Appendix 6. Laboratory internal control cards
AMPA0.15
Conc(�g/l)
0.100.050.002009/072009/082009/092009/102009/112009/12date2010/012010/022010/032010/042010/052010/06
Azoxystrobin0.15
Conc(�g/l)
0.100.050.002009/072009/082009/092009/102009/112009/12date2010/012010/022010/032010/042010/052010/06
Bentazone0.15
Conc(�g/l)
0.100.050.002009/072009/082009/092009/102009/112009/12date2010/012010/022010/032010/042010/052010/06
Bifenox acidBifenox acidBifenox-syre0.15
Conc(�g/l)
0.100.050.002009/072009/082009/092009/102009/112009/12date2010/012010/022010/032010/042010/052010/06
Figure A6.1Quality control data for pesticide analysis by laboratory 1. Internal laboratory control samples are indicated by squaresymbols and the nominal level is indicated by the solid grey line ( IQ measured,―IQ nominal concentration). External controlsamples are indicated by circles. Open circles indicate the nominal level (EQ nominal low,EQ nominal high), and closed circlesthe observed concentration ( EQ measured low,EQ measured high).
A6-1
Appendix 6. Laboratory internal control cards
Glyphosate0.15
Glyphosat
Conc(�g/l)
0.100.050.002009/072009/082009/092009/102009/112009/12date2010/012010/022010/032010/042010/052010/06
PPU (IN90741)IN709410.15
Conc(�g/l)
0.100.050.002009/072009/082009/092009/102009/112009/12date2010/012010/022010/032010/042010/052010/06
Tebuconazole0.15
Conc(�g/l)
0.100.050.002009/072009/082009/092009/102009/112009/12date2010/012010/022010/032010/042010/052010/06
Figure A6.1 continued.Quality control data for pesticide analysis by laboratory 1. Internal laboratory control samples are indicatedby square symbols and the nominal level is indicated by the solid grey line ( IQ measured,―
IQ nominal concentration). Externalcontrol samples are indicated by circles. Open circles indicate the nominal level ( EQ nominal low,EQ nominal high), andclosed circles the observed concentration ( EQ measured low,EQ measured high).
A6-2
