Roger Holten
Forsker
Vedlegg
CVBiografi
Jeg er utdannet Cand. Scient. i bioteknologi/miljømikrobiologi fra Norges landbrukshøgskole, nå NMBU (1995-2000) hvor hovedoppgaven omhandlet bioremediering av jord forurenset med PCB ved bruk av genmodifiserte bakterier (Pseudomonas putida). Etter dette jobbet jeg en kort periode som høgskolelektor ved Høgskolen i Telemark hvor jeg underviste i bl.a. grunnleggende toksikologi og fysiologi. Jeg har videre jobbet i vel 14 år i Landbrukstilsynet/Mattilsynet med miljøvurderinger (eksponeringsvurdering/modellering samt risikovurdering) og godkjenning av plantevernmdler før jeg startet i en stipendiatstilling her i NBIO i august 2015. PhD-prosjektet er en del av Smartcrop-prosjektet. Min PhD-avhandling ble ferdigstilt i januar 2019 og forsvart i disputas 14. mai 2019. Avhandlingens tittel er Effekten av frysing og tining på vanntransport og utlekking av plantevernmidler i delvis frossen jord. Fra 1. januar 2019 er jeg fast ansatt som forsker ved Avdeling pesticider og naturstoffkjemi. For tiden er jeg prosjektleder for prosjektene "Vegetasjonssoners effekt på avrenning av plantevernmidler", "Tabeller for utlekkingsrisiko til bruk ved planlegging av sprøyting" og "Utredning om de norske overflatevannscenariene", hvor alle avsluttes i løpet av 2021/22. Videre skal jeg lede prosjektene "Oppdatering av modellen WISPE og de norske overflatevannscenariene" og "Transport av plantevernmidler i vegetasjonssoner med makroporer". Alle disse prosjektene er finansiert over Handlingsplan for bærekraftig bruk av plantevernmidler 2016-2020. Jeg deltar også i flere andre større og mindre prosjekter der min rolle stort sett går på å bruke ulike eksponeringsmodeller for å vurdere hhv. utlekking, avrenning eller nedbrytning/persistens av plantevernmidler i miljøet.
Forfattere
Roger HoltenSammendrag
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Sammendrag
Field and laboratory studies show increased leaching of pesticides through macropores in frozen soil. Fast macropore flow has been shown to reduce the influence of pesticide properties on leaching, but data on these processes are scarce. The objective of this study was to investigate the effect of soil freezing and thawing on transport of pesticides with a range of soil sorption coefficients (Kf). To do this we conducted a soil column study to quantify the transport of bromide and five pesticides (2-methyl-4-chlorophenoxyacetic acid, clomazone, boscalid, propiconazole, and diflufenican). Intact topsoil and subsoil columns from two agricultural soils (silt and loam) in southeastern Norway were used in this experiment, and pesticides were applied to the soil surface in all columns. Half the columns were then frozen (−3°C), and the other half were left unfrozen (4°C). Columns were subjected to repeated irrigation events where 25 mm of rainwater was applied during 5 h at each event. Irrigations were followed by 14-d periods of freezing or refrigeration. Percolate was collected and analyzed for pesticides and bromide. Pesticide leaching was up to five orders of magnitude larger from frozen than unfrozen columns. Early breakthrough (<<1 pore volume) of high concentrations was observed for pesticides in frozen columns, indicating that leaching was dominated by preferential flow. The rank order in pesticide leaching observed in this study corresponded to the rank order of mean Kf values for the pesticides, and the results suggest that sorption plays a role in determining leaching losses even in frozen soil.
Forfattere
Roger Holten Frederik Bøe Marit Almvik Sheela Katuwal Marianne Stenrød Mats Larsbo Nicholas Jarvis Ole Martin EkloSammendrag
Limited knowledge and experimental data exist on pesticide leaching through partially frozen soil. The objective of this study was to better understand the complex processes of freezing and thawing and the effects these processes have on water flow and pesticide transport through soil. To achieve this we conducted a soil column irrigation experiment to quantify the transport of a non-reactive tracer and the herbicide MCPA in partially frozen soil. In total 40 intact topsoil and subsoil columns from two agricultural fields with contrasting soil types (silt and loam) in South-East Norway were used in this experiment. MCPA and bromide were applied on top of all columns. Half the columns were then frozen at −3 °C while the other half of the columns were stored at +4 °C. Columns were then subjected to repeated irrigation events at a rate of 5 mm artificial rainwater for 5 h at each event. Each irrigation was followed by 14-day periods of freezing or refrigeration. Percolate was collected and analysed for MCPA and bromide. The results show that nearly 100% more MCPA leached from frozen than unfrozen topsoil columns of Hov silt and Kroer loam soils. Leaching patterns of bromide and MCPA were very similar in frozen columns with high concentrations and clear peaks early in the irrigation process, and with lower concentrations leaching at later stages. Hardly any MCPA leached from unfrozen topsoil columns (0.4–0.5% of applied amount) and concentrations were very low. Bromide showed a different flow pattern indicating a more uniform advective-dispersive transport process in the unfrozen columns with higher con- centrations leaching but without clear concentration peaks. This study documents that pesticides can be pre- ferentially transported through soil macropores at relatively high concentrations in partially frozen soil. These findings indicate, that monitoring programs should include sampling during snow melt or early spring in areas were soil frost is common as this period could imply exposure peaks in groundwater or surface water.
Forfattere
Marianne Stenrød Kathinka Lang Marit Almvik Roger Holten Agnethe Christiansen Xingang Liu Qiu JingSammendrag
To ensure compliance with food safety regulations, monitoring programs and reliable analytical methods to detect relevant chemical pollutants in food and the environment are key instruments. Pesticides are an important part of pest management in agriculture to sustain and increase crop yields and control post-harvest decay, while pesticide residues in food may pose a risk to human health. Thus, the levels of pesticide residues in food must be controlled and should align with Maximum Residue Levels regulations to ensure food safety. Food safety monitoring programs and analytical methods for pesticide residues and metabolites are well developed. Future developments to ensure food safety must include the increased awareness and improved regulatory framework to meet the challenges with natural toxins, emerging contaminants, novel biopesticides, and antimicrobial resistance in food and the environment. The reality of a complex mixture of pollutants, natural toxins, and their metabolites potentially occurring in food and the environment implies the necessity to consider combined effects of chemicals in risk assessment. Here, we present challenges, monitoring efforts, and future perspectives for chemical food safety focused on the importance of current developments in high-resolution mass spectrometry (HRMS) technologies to meet the needs in food safety and environmental monitoring.
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Det nasjonale overvåkingsprogrammet JOVA (Program for jord- og vannovervåking i landbruket) overvåker nedbørfelt som er representative for de ulike jordbruksproduksjonene og –regionene i Norge og er valgt ut mht. klima, jordsmonn, driftspraksis og -intensitet. Det er i dette prosjektet analysert overvåkingsdata for et utvalg vannløselige og mobile plantevernmidler (MCPA, bentazon, metribuzin, metalaksyl) som har vært godkjent i mange år og som gjenfinnes ofte i vannmiljø og dermed utgjør et størst mulig datagrunnlag for å finne eventuelle sammenhenger mellom funn, værforhold og driftspraksis. De gjennomførte analysene viste imidlertid at dataene ikke er av et slikt format eller omfang at det er mulig å hente ut informasjon som kan benyttes direkte til praktisk veiledning for en mer bærekraftig bruk av plantevernmidler. Dette vil kreve mye mer detaljerte og tidkrevende analyser, eventuelt modellutvikling og modellsimuleringer, som ikke er forenlige med formålet med og ressursene tilgjengelig for dagens overvåking.
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Plantevernmidler som sprøytes på åkeren kan komme på avveie, gjerne ved utlekking mot grunnvann. Bønder har få verktøy til hjelp for å vurdere om et plantevernmiddel kan lekke nedover i jorda mot grunnvannet under jord- og klimaforhold på deres eget gårdsbruk.
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Datamodellen WISPE ble ferdigutviklet i 2013 for å kunne undersøke avrenning og utlekking av plantevernmidler i miljøet under norske forhold. Formålet med dette prosjektet har bl.a. vært å oppdatere WISPE-modellen og gjøre den enda mer brukervennlig. Modellverktøyet WISPE er videreutviklet blant annet i henhold til oppdateringer anbefalt for EU-modeller av det såkalte FOCUSRepair- prosjektet. Mulighet for å kunne estimere effekten av vegetasjonssoner med ulik bredde er også lagt inn. Modellen er endret slik at det er blitt enklere å videreutvikle verktøyet og legge til nye data uten bruk av programmeringseksperter samt at det er enkelt å kjøre modellen med forskjellige klimafiler for å se på effekten av klimaendringer. Det er utviklet en brukermanual som skal gjøre det lettere å bruke modellen, både for forvaltning, industri og innen forskningen. Waterborne Environmental har stått for programmering og all teknisk utvikling i dette prosjektet. NIBIO har bidratt med data og kunnskap om norske forhold samt testing og innspill underveis. Waterborne har innhentet innspill fra plantevernmiddelindustrien samt utviklere i Europa som jobber med EUmodellene. Resultatene fra prosjektet er formidlet på ulike internasjonale konferanser og i et eget møte med Mattilsynet og en representant fra industrien (Bayer CropScience). Hovedleveransen fra prosjektet er det oppdaterte modellverktøyet og brukermanualen. Informasjon om modellen, brukermanualen og selve modellen gjøres tilgjengelig på NIBIOs nettsider i løpet av våren 2023.
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Forfattere
Roger HoltenSammendrag
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Roger Holten Randi Bolli Eivind Solbakken Trond Christen Anstensrud Svein Bovim Kåre Oskar Larsen Ole Martin EkloSammendrag
Bønder i Norge mangler gode verktøy for å kunne vurdere om plantevernmidlene de kan bruke, vil kunne lekke til grunnvann under deres jord- og klimaforhold i deres region. I dette prosjektet er det søkt å lage brukervennlige tabeller som indikerer sannsynligheten for utlekking av plantevernmidler under ulike jord- og klimaforhold. Målsetningen er at man ved hjelp av tabellene kan finne det mest miljøvennlige alternativet blant de aktuelle plantevernmidlene bonden kan velge blant. Det er samlet inn store mengder data på klima, jordsmonn og kulturutvikling for potet/nypotet og korn (høst- og vårkorn) i de store landbruksregionene i Norge (Rogaland og Sørlandet, Østlandet, Innlandet og Trøndelag). Dataene er benyttet til å tilpasse grunnvannsmodellen MACRO-DB for norske forhold. Det er også samlet inn data på alle godkjente plantevernmidler i disse kulturene. Sammen danner dette basis for modellsimuleringer som gir en indikasjon på om et plantevernmiddel kan lekke til grunnvann og i så fall i hvilken konsentrasjon. Disse konsentrasjonene er videre presentert i utlekkingstabeller i form av fargekoder som indikerer sannsynligheten for utlekking. Utlekkingstabellene gir da en fargekode for hver av de ulike plantevernmidlene godkjent i de aktuelle kulturene for 10 ulike jordtyper i 4 ulike regioner. Disse utlekkingstabellene finnes i et eget vedlegg til denne rapporten.
Forfattere
Sophie Mentzel Merete Grung Roger Holten Knut-Erik Tollefsen Marianne Stenrød S. Jannicke MoeSammendrag
The use of Bayesian networks (BN) for environmental risk assessment has increased in recent years as they offer a more transparent way to characterize risk and evaluate uncertainty than the traditional risk assessment paradigms. In this study, a novel probabilistic approach applying a BN for risk calculation was further developed and explored by linking the calculation a risk quotient to alternative future scenarios. This extended version of the BN model uses predictions from a process-based pesticide exposure model (World Integrated System for Pesticide Exposure - WISPE) in the exposure characterization and toxicity test data in the effect characterization. The probability distributions for exposure and effect are combined into a risk characterization (i.e. the probability distribution of a risk quotient), a common measure of the exceedance of an environmentally safe exposure threshold. The BN model was used to account for variabilities of the predicted pesticide exposure in agricultural streams, and inter-species variability in sensitivity to the pesticide among freshwater species. In Northern Europe, future climate scenarios typically predict increased temperature and precipitation, which can be expected to cause an increase in weed infestations, plant disease and insect pests. Such climate-related changes in pest pressure in turn can give rise to altered agricultural practices, such as increased pesticide application rates, as an adaptation to climate change. The WISPE model was used to link a set of scenarios consisting of two climate models, three pesticide application scenarios and three periods (year ranges), for a case study in South-East Norway. The model was set up for the case study by specifying environmental factors such as soil properties and field slope together with chemical properties of pesticides to predict the pesticide exposure in streams adjacent to the agricultural fields. The model was parameterized and evaluated for five selected pesticides: the three herbicides clopyralid, fluroxypyr-meptyl, and 2-(4-chloro-2-methylphenoxy) acetic acid (MCPA), and the two fungicides prothiocanzole and trifloxystrobin. This approach enabled the calculation and visualization of probability distribution of the risk quotients for the future time horizons 2050 and 2085. The risk posed by the pesticides were in general low for this case study, with highest probability of the risk quotient exceeding 1 for the two herbicides fluroxypyr-meptyl and MCPA. The future climate projections used here resulted in only minor changes in predicted exposure concentrations and thereby future risk. However, a stronger increase in risk was predicted for the scenarios with increased pesticide application, which can represent an adaptation to a future climate with higher pest pressures. In the current study, the specific BN model predictions were constrained by an existing set of climate projections which represented only one IPCC scenario (A1B) and two climate models. Further advancement of the BN modelling demonstrated herein, including more recent climate scenarios and a larger set of climate models, is anticipated to result in more relevant risk characterization also for future climate conditions. This probabilistic approach will have the potential to aid targeted management of ecological risks in support of future research, industry and regulatory needs.
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Forfattere
Sophie Mentzel Merete Grung Knut-Erik Tollefsen Marianne Stenrød Roger Holten S. Jannicke MoeSammendrag
Future weather patterns are expected to result in increased precipitation and temperature, in Northern Europe. These changes can potentially cause an increase in plant disease and insect pests which will alter agricultural practice amongst other things the used crop types and application patterns of pesticides. We use a Bayesian network to explore a probabilistic risk assessment approach to better account for variabilities and magnitudes of pesticide exposure to the aquatic ecosystem. As Bayesian networks link selected input and output variables from various models and other information sources, they can serve as meta-models. In this study, we are using a pesticide fate and transport models (e.g. WISPE) with specific environmental factors such as soil and site parameters together with chemical properties and climate scenarios that are linked to a representative Norwegian study area. The derived exposure of pesticide of the study area is integrated in the Bayesian network model to estimate the risk to the aquatic ecosystem also integrating an effect distribution derived from toxicity test. This Bayesian network model will allow to incorporate climate predictions into ecological risk assessment.
Forfattere
Yanli Man Marianne Stenrød Chi Wu Marit Almvik Roger Holten Jihong Liu Clarke Shankui Yuan Xiaohu Wu Jun Xu Fengshou Dong Yongquan Zheng Xingang LiuSammendrag
Difenoconazole is a widely used triazole fungicide that has been frequently detected in the environment, but comprehensive study about its environmental fate and toxicity of potential transformation products (TPs) is still lacking. Here, laboratory experiments were conducted to investigate the degradation kinetics, pathways, and toxicity of transformation products of difenoconazole. 12, 4 and 4 TPs generated by photolysis, hydrolysis and soil degradation were identified via UHPLC-QTOF/MS and the UNIFI software. Four intermediates TP295, TP295A, TP354A and TP387A reported for the first time were confirmed by purchase or synthesis of their standards, and they were further quantified using UHPLC-MS/MS in all tested samples. The main transformation reactions observed for difenoconazole were oxidation, dechlorination and hydroxylation in the environment. ECOSAR prediction and laboratory tests showed that the acute toxicities of four novel TPs on Brachydanio rerio, Daphnia magna and Selenastrum capricornutum are substantially lower than that of difenoconazole, while all the TPs except for TP277C were predicted chronically very toxic to fish, which may pose a potential threat to aquatic ecosystems. The results are important for elucidating the environmental fate of difenoconazole and assessing the environmental risks, and further provide guidance for scientific and reasonable use.
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Plantevernmidler er et viktig verktøy i dagens plantevernpraksis i jordbruket for å sikre gode avlinger. Miljørisikoen knyttet til det enkelte plantevernmiddel vurderes nøye før det godkjennes for bruk, men langvarig overvåking er nødvendig for å avdekke de faktiske miljøkonsentrasjoner og - effekter etter forskriftsmessig bruk av plantevernmidler. Sveriges nasjonale miljøovervåkingsprogram for plantevernmidler startet i 2002. Hovedmålet med programmet er å følge langtidstrender i påvirkningen av jordbrukets plantevernmiddelbruk på kvaliteten av overflate- og grunnvann, samt å bestemme miljøkonsentrasjonene av plantevernmidler i sediment, luft og nedbør. Formålet med denne evalueringen var å vurdere styrker og svakheter ved overvåkingsprogrammet, samt behov for endringer i den praktiske gjennomføringen, rapporteringsprosedyrer og målsetningen med programmet. Denne evalueringen vurderer også behovene hos de aktuelle sluttbrukergruppene for programmet som inkluderer svensk landbruks- og miljøforvaltning, rådgivningstjenesten i landbruket, bønder og bondeorganisasjoner mv.
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Forfattere
Sophie Mentzel Merete Grung Knut-Erik Tollefsen Marianne Stenrød Roger Holten S. Jannicke MoeSammendrag
In Northern Europe, future changes in land-use and weather patterns are expected to result in increased precipitation and temperature this may cause an increase in plant disease and insect pests. In addition, predicted population increase will change the production demands and in turn alter agricultural practices such as crop types and with that the use pattern of pesticides. Considering these variabilities and magnitudes of pesticide exposure to the aquatic environment still needs to be accounted for better in current probabilistic risk assessment. In order to improve ecological risk assessment, this study explores an alternative approach to probabilistic risk assessment using a Bayesian Network, as these can serve as meta-models that link selected input and output variables from other models and information sources. The developed model integrates variability in both exposure and effects in the calculation of risk estimate. We focus on environmental risk of pesticides in two Norwegian case study region representatives of northern Europe. Using pesticide fate and transport models (e.g. WISPE), environmental factors such as soil and site parameters together with chemical properties and climate scenarios (current and predicted) are linked to the exposure of a pesticide in the selected study area. In the long term, the use of tools based on Bayesian Network models will allow for a more refined assessment and targeted management of ecological risks by industry and policy makers.
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Marit Almvik Fengshou Dong Roger Holten Agnethe Christiansen Ole Martin Eklo Marianne Stenrød Yanbo LiSammendrag
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Roger HoltenSammendrag
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Roger HoltenSammendrag
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Sophie Mentzel Merete Grung Knut-Erik Tollefsen Marianne Stenrød Roger Holten S. Jannicke MoeSammendrag
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Preferential flow may become significant in partially frozen soils because infiltration can occur through large, initially air-filled pores surrounded by a soil matrix with limited infiltration capacity. The objectives of this study were to develop and evaluate a dual-permeability approach for simulating water flow and heat transport in macroporous soils undergoing freezing and thawing. This was achieved by introducing physically based equations for soil freezing and thawing into the dual-permeability model MACRO. Richards’ equation and the heat flow equation were loosely coupled using the generalized Clapeyron equation for the soil micropore domain. Freezing and thawing of macropore water is governed by a first-order equation for energy transfer between the micropore and macropore domains. We assumed that macropore water was unaffected by capillary forces, so that water in macropores freezes at 0°C. The performance of the model was evaluated for four test cases: (i) redistribution of water in the micropore domain during freezing, (ii) a comparison between the first-order energy transfer approach and the heat conduction equation, (iii) infiltration and water flow in frozen soil with an initially air-filled macropore domain, and (iv) thawing from the soil surface during constant-rate rainfall. Results show that the model behaves in accordance with the current understanding of water flow and heat transport in frozen macroporous soil. To improve modeling of water and heat flow in frozen soils, attention should now be focused on providing experimental data suitable for evaluating models that account for macropore flow.
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Roger HoltenSammendrag
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Roger HoltenSammendrag
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Roger HoltenSammendrag
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Utlekking av plantevernmidler i jord øker betydelig under fryse-tineepisoder. Det viser ny forskning fra Norsk institutt for bioøkonomi (NIBIO).
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Field and laboratory studies show increased leaching of pesticides through macropores in frozen soil. Fast macropore flow has been shown to reduce the influence of pesticide properties on leaching, but data on these processes are scarce. The objective of this study was to investigate the effect of soil freezing and thawing on transport of pesticides with a range of soil sorption coefficients (Kf). To do this we conducted a soil column study to quantify the transport of bromide and five pesticides (2-methyl-4-chlorophenoxyacetic acid, clomazone, boscalid, propiconazole, and diflufenican). Intact topsoil and subsoil columns from two agricultural soils (silt and loam) in southeastern Norway were used in this experiment, and pesticides were applied to the soil surface in all columns. Half the columns were then frozen (−3°C), and the other half were left unfrozen (4°C). Columns were subjected to repeated irrigation events where 25 mm of rainwater was applied during 5 h at each event. Irrigations were followed by 14-d periods of freezing or refrigeration. Percolate was collected and analyzed for pesticides and bromide. Pesticide leaching was up to five orders of magnitude larger from frozen than unfrozen columns. Early breakthrough (<<1 pore volume) of high concentrations was observed for pesticides in frozen columns, indicating that leaching was dominated by preferential flow. The rank order in pesticide leaching observed in this study corresponded to the rank order of mean Kf values for the pesticides, and the results suggest that sorption plays a role in determining leaching losses even in frozen soil.
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Forfattere
Roger Holten Frederik Bøe Marit Almvik Sheela Katuwal Marianne Stenrød Mats Larsbo Nicholas Jarvis Ole Martin EkloSammendrag
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Roger HoltenSammendrag
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Freezing and thawing have large effects on water flow in soils since ice may block a large part of the pore space and thereby prevent infiltration and flow through the soil. This, in turn, may have consequences for contaminant transport. For example, transport of solutes contained at or close to the soil surface can be rapidly transported through frozen soils in large pores that were air filled at the time of freezing. Accounting for freezing and thawing could potentially improve model predictions used for risk assessment of contaminant leaching. A few numerical models of water flow through soil accounts for freezing by coupling Richards’ equation and the heat flow equation using of the generalized Clapeyron equation, which relates the capillary pressure to temperature during phase change. However, these models are not applicable to macroporous soils. The objective of this study was to develop and evaluate a dual-permeability approach for simulating water flow in soil under freezing and thawing conditions. To achieve this we extended the widely used MACRO-model for water flow and solute transport in macroporous soil. Richards’ equation and the heat flow equation were loosely coupled using the Clapeyron equation for the soil micropore domain. In accordance with the original MACRO model, capillary forces were neglected for the macropore domain and conductive heat flow in the macropores was not accounted for. Freezing and thawing of macropore water, hence, were solely governed by heat exchange between the pore domains. This exchange included a first-order heat conduction term depending on the temperature difference between domains and the diffusion pathlength (a proxy variable related to the distance between macropores) and convective heat flow. As far as we know, there are no analytical solutions available for water flow during freezing and thawing and laboratory data is limited for evaluation of water flow through macropores. In order to evaluate the new model approach we therefore first compared simulation results of water flows during freezing for the micropore domain to existing literature data. Our model was shown to give similar results as other available models. We then compared the first-order conductive heat exchange during freezing to a full numerical solution of heat conduction. Finally, simulations were run for water flow through frozen soil with initially air-filled macropores for different boundary conditions. Simulation results were sensitive to parameters governing the heat exchange between pore domains for both test cases.
Forfattere
Roger Holten Frederik Bøe Marit Almvik Marianne Stenrød Mats Larsbo Nicholas Jarvis Ole Martin EkloSammendrag
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Forfattere
Roger Holten Frederik Bøe Marit Almvik Sheela Katuwal Marianne Stenrød Mats Larsbo Nicholas Jarvis Ole Martin EkloSammendrag
Limited knowledge and experimental data exist on pesticide leaching through partially frozen soil. The objective of this study was to better understand the complex processes of freezing and thawing and the effects these processes have on water flow and pesticide transport through soil. To achieve this we conducted a soil column irrigation experiment to quantify the transport of a non-reactive tracer and the herbicide MCPA in partially frozen soil. In total 40 intact topsoil and subsoil columns from two agricultural fields with contrasting soil types (silt and loam) in South-East Norway were used in this experiment. MCPA and bromide were applied on top of all columns. Half the columns were then frozen at −3 °C while the other half of the columns were stored at +4 °C. Columns were then subjected to repeated irrigation events at a rate of 5 mm artificial rainwater for 5 h at each event. Each irrigation was followed by 14-day periods of freezing or refrigeration. Percolate was collected and analysed for MCPA and bromide. The results show that nearly 100% more MCPA leached from frozen than unfrozen topsoil columns of Hov silt and Kroer loam soils. Leaching patterns of bromide and MCPA were very similar in frozen columns with high concentrations and clear peaks early in the irrigation process, and with lower concentrations leaching at later stages. Hardly any MCPA leached from unfrozen topsoil columns (0.4–0.5% of applied amount) and concentrations were very low. Bromide showed a different flow pattern indicating a more uniform advective-dispersive transport process in the unfrozen columns with higher con- centrations leaching but without clear concentration peaks. This study documents that pesticides can be pre- ferentially transported through soil macropores at relatively high concentrations in partially frozen soil. These findings indicate, that monitoring programs should include sampling during snow melt or early spring in areas were soil frost is common as this period could imply exposure peaks in groundwater or surface water.
Forfattere
Roger Holten Frederik Bøe Marit Almvik Marianne Stenrød Mats Larsbo Nicholas Jarvis Ole Martin EkloSammendrag
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Roger Holten Frederik Bøe Marit Almvik Marianne Stenrød Mats Larsbo Nicholas Jarvis Ole Martin EkloSammendrag
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Marit Almvik Marianne Stenrød Ole Martin Eklo Nina Holteberg Paulien Jakobje Mulder Roger Holten Roger RosethSammendrag
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Marianne Stenrød Marit Almvik Ole Martin Eklo Anne Louise Gimsing Roger Holten Kai Künnis-Beres Mats Larsbo Linas Putelis Katri Siimes Inara Turka Jaana Uusi-KämppäSammendrag
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Marit Almvik Randi Bolli Agnethe Christiansen Ole Martin Eklo Roger Holten Paulien Jakobje Mulder Gunvor Senneset Marianne StenrødSammendrag
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Marit Almvik Randi Bolli Agnethe Christiansen Ole Martin Eklo Roger Holten Paulien Mulder Gunvor Senneset Marianne StenrødSammendrag
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Marit Almvik Randi Bolli Agnethe Christiansen Ole Martin Eklo Roger Holten Paulien Jakobje Mulder Gunvor SennesetSammendrag
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Marit Almvik Gunnhild Riise Trond Børresen Randi Bolli Agnethe Christiansen Sven R. Odenmarck Roger HoltenSammendrag
Til tross for at lavdosemidler har vært brukt i Norge i flere tiår, vet vi lite om hvordan stoffene oppfører seg i miljøet under norske forhold. Våre forsøk viser at enkelte lavdosemidler og nedbrytingsprodukter er mobile og transporteres bort fra kornfeltet gjennom dren og avrenning. Målte konsentrasjoner er lave, men kan overstige norske verdier for miljøfarlighet.
Forfattere
Marit Almvik Gunnhild Riise Randi Bolli Trond Børresen Agnethe Christiansen Sven R. Odenmarck Roger HoltenSammendrag
The report presents the results from multi-year field studies of transport of the sulfonylurea herbicides tribenuron-methyl and amidosulfuron in a barley field in Norway. A method for sample preparation of water samples and LC-MS/MS analysis of 6 sulfonylurea herbicides tribenuron-methyl, amidosulfuron, metsulfuron-methyl, iodosulfuron-methyl, thifensulfuron-methyl, rimsulfuron) and 5 degradation products (INL5296, INA4098, AEF101630, IN70941, IN70942) is also described.
Sammendrag
This is a final report for the project Norwegian Scenarios from the periods 1999-2002 and 2005- 2008, mainly focusing on the simulations done with the models MACRO and PRZM. The aim of this project was to improve the risk assessment work in Norway by establishing surface- and groundwater scenarios which could be representative for Norwegian conditions and to later use these for approval of new pesticides. This project has been a cooperation between Bioforsk Plantehelse, Norwegian University of Life Sciences and the Norwegian Food Safety Authority.
Forfattere
Ole Martin Eklo Marit Almvik Randi Bolli Trond Børresen Terje Haraldsen Lars Egil Haugen Roger Holten Gunnhild RiiseSammendrag
This is a final report for the project Norwegian Scenarios II, part two, that has been performed in collaboration between Bioforsk Plant Health and Plant Protection, The Norwegian University of Life Sciences and the Norwegian Food Safety Authority. The aim of the project was to establish Norwegian scenarios for the models PRZM and MACRO and to use them for approval of new pesticides.
Forfattere
Trond Hofsvang Heidi Heggen Helge Sjursen Ingun Fjærbu Anne G. Kraggerud Katrine T. Persson Anna Mehl Knut Elkjær Anne Marie Heiberg Reidunn Stokke Roger Holten Ole Martin Eklo Nils Bjugstad Dag Frode FridheimSammendrag
Brukere av plantevernmidler ønsker å produsere trygg mat og forvalte naturressursene på en god måte. Kunnskap om riktig bruk og handtering av plantevernmidlene er en forutsetning for å oppfylle dette ønsket. Slike kunnskaper vil dessuten bidra til bedre økonomi i planteproduksjonen. Med "Handlingsplan for redusert bruk av plantevernmidler (1990-1994)" ønsket Stortinget å legge til rette for, og sikre slike kunnskaper hos alle brukere av plantevernmidler gjennom et organisert kursopplegg med avsluttende eksamen som gir rett til et personlig autorisasjonsbevis også kalt sprøytesertifikat. Etter evalueringg av handlingsplanen vedtok Landbruksdepartementet en ny handlingsplan "Handlingsplan for redusert risiko ved bruk av plantevernmidler (1998-2002)". I denne videreføres autorisasjonsordningen. Denne boka gir deg oppdatert basiskunnskap om riktig bruk og handtering av plantevernmidler. Boka inngår i kursmateriellet til autorisasjonsordningen for handtering og bruk av plantevernmidler.
