Per-Erik Mellander

Per-Erik Mellander
TEAGASC - The Agriculture and Food Development Authority · Department of Environment, Soils and Landuse

PhD, MSc

About

119
Publications
23,274
Reads
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3,485
Citations
Citations since 2017
62 Research Items
2089 Citations
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Education
October 1998 - October 2003
Swedish University of Agricultural Sciences
Field of study
  • Environmental Assessment
September 1990 - June 1994
Uppsala University
Field of study
  • Physical Geography

Publications

Publications (119)
Article
There are uncertainties in the definition of phosphorus (P) and nitrogen (N) transfer pathways within agricultural river catchments due to spatiotemporal variations such as water recharge and the farming calendar, or catchment soil and hydrogeological properties. This can have implications for mitigation policies. This study combined detailed pathw...
Article
In this paper we analyze four years of data from simultaneous high–frequency monitoring of streamflow and phosphorus (P) concentration. This was to investigate hydrolological flow paths and P transfer pathways from diffuse sources in two intensively farmed river catchments (ca. 10 km2) with contrasting flow controls and dominating flow paths. Catch...
Article
Full-text available
Management of agricultural diffuse pollution to water remains a challenge and is influenced by the complex interactions of rainfall-runoff pathways, soil and nutrient management, agricultural landscape heterogeneity and biogeochemical cycling in receiving water bodies. Amplified cycles of weather can also influence nutrient loss to water although t...
Article
Full-text available
The agri-food economy can be a significant driver of water quality pressures but the role of hydro-meteorological patterns in a changing climate also requires consideration. For this purpose, an assessment was made of a ten-year synchronous high temporal resolution water quality and hydro-meteorological dataset in Irish agricultural catchments. Cha...
Article
Full-text available
Efficient and targeted measures to mitigate nutrient losses to water are required to meet the challenges of increased food production and climate change. Diffuse pollution management requires insight into the underlying processes of nutrient transfer and its stability, but there are no standardized ways to evaluate phosphorus (P) mobilization and d...
Article
This study reports the kinetics and isotherms of the adsorption of five herbicides, MCPA, mecoprop-P, 2,4-D, fluroxypyr and triclopyr, from aqueous solutions onto a range of raw and pyrolysed waste materials originating from an industrial setting. The raw waste materials investigated demonstrated little capability for any herbicide adsorption. Gran...
Poster
Full-text available
The acid herbicide MCPA is widely detected in water bodies, especially where there are frequent applications to grassland agriculture. However, there is an evidence gap relating to MCPA pathways between land use application/mobilisation and detection in water bodies. To address this, an enhanced water quality dataset was used to quantify exported M...
Article
Full-text available
Detection of the agricultural acid herbicide MCPA (2-methyl-4-chlorophenoxyacetic acid) in drinking water source catchments is of growing concern, with economic and environmental implications for water utilities and wider ecosystem services. MCPA is poorly adsorbed to soil and highly mobile in water, but hydrological pathway processes are relativel...
Article
Full-text available
The environmental loss of nitrogen in agricultural landscapes has pervasive consequences, including human health implications, eutrophication, loss of habitat biodiversity and greenhouse gas emissions. The efficacy of mitigation strategies designed to control or prevent nitrate contamination of waterbodies requires an understanding of catchment sca...
Article
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This paper presents a novel scoring system which facilitates a relative ranking of pesticide risk to human health arising from contaminated drinking water. This method was developed to identify risky pesticides to better inform monitoring programmes and risk assessments. Potential risk was assessed considering pesticide use, chronic human health ef...
Article
Full-text available
Meeting sustainable food production challenges requires efficient ways to manage nutrients and mitigate the losses of nitrogen (N) and phosphorus (P) to water. Future nutrient management therefore requires a clearer understanding of the relative influence of soils, geology, farm practice, landscape and weather on the propensity for nutrients to be...
Article
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Pesticides are widely employed as a cost‐effective means of reducing the impacts of undesirable plants and animals. The aim of this paper is to develop a risk ranking of transmission of key pesticides through soil to waterways, taking into account physiochemical properties of the pesticides (soil half‐life, and water solubility), soil permeability,...
Article
Water quality degradation can be caused by excessive agricultural nutrient transfers from fertilised soils exposed to wet weather. Mitigation measures within the EU Nitrates Directive aim to reduce this pressure by including ‘closed’ fertiliser spreading periods during wet months. For organic fertilisers such as slurry and manure, this closed perio...
Article
Full-text available
Colloids can be important for facilitated transfer of phosphorus (P) to groundwater (GW) and contribute to elevated P concentrations later delivered to surface water. To assess the role of colloidal P and other P fractions in delivery processes via below-ground pathways, this study investigated the influence of catchment and flow event characterist...
Chapter
Agriculture exerts a variety of pressures on inland waters, including nutrient loss from fertilizers, sediment transfer, changes in hydromorphology, and diverse emerging contaminants. This chapter presents four case studies demonstrating some of the water quality issues related to modern agriculture, including nutrient pressures in an intensive gra...
Article
Until recent decades, most monitoring of surface waters relied exclusively on samples analysed in the laboratory for ecologically and management-relevant parameters. It is now possible, however, to automatically monitor many parameters using in-situ sensors and to provide remote web-based access to these data. Such data are typically provided at fr...
Article
Full-text available
Background The use of soil phosphorus (P) tests and index systems provides a guide for agronomic nutrient requirements and is frequently also used to estimate risk of P losses to watercourses. Use of soil testing and management based on the results thereof is mandated in some regions. Several P extraction methods are available which evaluate differ...
Article
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Opportunistic macroalgal blooms have been used for the assessment of the ecological status of coastal and estuarine areas in Europe. The use of earth observation (EO) data sets to map green algal cover based on a Normalized Difference Vegetation Index (NDVI) was explored. Scenes from Sentinel-2A/B, Landsat-5, and Landsat-8 missions were processed f...
Article
Full-text available
Anthelmintics are antiparasitic drugs used to control helminthic parasites such as nematodes and trematodes in animals, particularly those exposed through pasture-based production systems. Even though anthelmintics have been shown to be excreted into the environment in relatively high amounts as unmetabolised drug or transformation products (TPs),...
Article
Full-text available
A historic lack of continuous stream nutrient monitoring at the catchment scale limits understanding of the effects of snowstorms. The most significant snowstorm since 1985, nicknamed "the Beast from the East", occurred in February-March 2018. High-frequency stream outlet monitoring in two close but hydrologically and agriculturally contrasting cat...
Article
Full-text available
Nutrient and contaminant losses in agricultural landscapes are directly controlled by hydrological (flow pathways), chemical (sorption, speciation and transformations), biological processes (fixation, uptake) and indirectly by demographic (growing population), economic (food production) and societal drivers (individual attitudes, farming tradition)...
Article
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Despite an improvement of water quality across Europe there are many pollution hotspots for both nitrates and PPPs, mainly due to agricultural activities. The BMPs and MMs to reduce pollution from agriculture are well known, and there are policy instruments in place to ensure drinking water standards, but the current approach has not been efficient...
Article
Full-text available
Clean water is a precious resource, and policies/programmes are implemented worldwide to protect and/or improve water quality. Faecal pollution can be a key contributor to water quality decline causing eutrophication through nutrient enrichment and pathogenic contamination. The robust sourcing of faecal pollutants is important to be able to target...
Article
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Drinking water governance is challenging with different perceptions and priorities among stakeholders in different countries. To make provision for drinking water protection in agricultural areas, governance systems need to be mapped for bottlenecks to be identified and solutions highlighted. To address this a system thinking approach was used in a...
Article
Colloid-facilitated transport can be important for preferential transfer of phosphorus (P) through the soil profile to groundwater and may in part explain elevated P concentrations in surface water during baseflow and particularly high flow conditions. To investigate the potential for colloidal P (Pcoll) mobilisation in soils, this study assessed t...
Article
Full-text available
Intensification of the food production system to meet increased global demand for food has led to veterinary pharmaceuticals becoming a critical component in animal husbandry. Anticoccidials are a group of veterinary products used to control coccidiosis in food-producing animals, with primary prophylactic use in poultry production. Excretion in man...
Preprint
Full-text available
In well-drained agricultural catchments transport of phosphorus (P) to groundwater (GW) can be controlled by static and dynamic factors and where surface water is GW fed this can lead to elevated P concentrations at the catchment outlet. In order to better control P transport along hillslopes a spatial and temporal conceptual view of P loss to GW m...
Article
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Worldwide herbicide use in agriculture, whilst safeguarding yields also presents water quality issues. Controlling factors in agricultural catchments include both static and dynamic parameters. The present study investigated the occurrence of herbicides in streams and groundwater in two meso-scale catchments with contrasting flow controls and agric...
Article
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Presentation of PestMan project objectives
Article
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A sensitive and selective method was developed and validated for the determination of 26 anticoccidial compounds (six ionophores and twenty chemical coccidiostats) in surface and groundwater samples at parts-per-quadrillion (pg L-1) to parts-per-trillion (ng L-1) levels by ultra-high performance liquid chromatography with tandem mass spectrometry d...
Article
Full-text available
Due to its high solubility and poor adsorption to the soil matrix, the post‐emergence herbicide 2‐methyl‐4‐chlorophenoxyacetic acid (MCPA) is susceptible to transport into surface and groundwater bodies, where it can result in compromised water quality and breaches of legislative standards. However, there is still poor understanding of catchment sc...
Article
Full-text available
Water and pollutant fluxes from combined sewer overflows (CSO) have a significant impact on receiving waters. The random nature of rainfall forcing dominates the variability of sewer discharges, pollutant loads, and concentrations. An analytical model developed here shows how sewer network topology and rainfall properties variously impact the stoch...
Preprint
Water and pollutant fluxes from combined sewer overflows (CSO) have a significant impact on receiving waters. The random nature of rainfall forcing dominates the variability of sewer discharges, pollutant loads, and concentrations. An analytical model developed here, shows how sewer network topology and rainfall properties variously impact the stoc...
Article
Freshwaters worldwide are affected by multiple stressors. Timing of inputs and pathways of delivery can influence the impact stressors have on freshwater communities. In particular, effects of point versus diffuse nutrient inputs on stream macroinvertebrates are poorly understood. Point-source inputs tend to pose a chronic problem, whereas diffuse...
Article
Full-text available
High-resolution water quality monitoring indicates recurring elevation of stream phosphorus concentrations during low-flow periods. These increased concentrations may exceed Water Framework Directive (WFD) environmental quality standards during ecologically sensitive periods. The objective of this research was to identify source, mobilization, and...
Article
Full-text available
The evolution of phosphorus (P) management decision support tools (DSTs) and systems (DSS), in support of food and environmental security has been most strongly affected in developed regions by national strategies (i) to optimize levels of plant available P in agricultural soils, and (ii) to mitigate P runoff to water bodies. In the United States,...
Article
Full-text available
A comprehensive multiresidue method was developed and validated for the determination of 40 anthelmintic compounds, including 13 transformation products, in surface and groundwater samples at sub nanogram per litre (ng L −1) levels. Anthelmintic residues were extracted from unfiltered water samples using polymeric divinylbenzene solid phase extract...
Article
Full-text available
Forecasting pesticide residues in soils in real time is essential for agronomic purposes, to manage phytotoxic effects, and in catchments to manage surface and ground water quality. This has not been possible in the past due to both modelling and measurement constraints. Here, the analytical transient probability distribution (pdf) of pesticide con...
Article
Full-text available
Reducing legacy soil phosphorus (P) is recognised as an effective measure to mitigate diffuse P losses from agricultural landscapes and alleviate trophic pressure to freshwaters systems. Accounting for the distribution of P within farms is critical in identifying fields of agronomic underperformance and/or environmental risk to water as a consequen...
Article
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In this paper, we outline several recent insights for the priorities and challenges for future research for reducing phosphorus (P) based water eutrophication in the agricultural landscapes of Northwest Europe. We highlight that new research efforts best be focused on headwater catchments as they are a key influence on the initial chemistry of the...
Article
Multiple stressors affect stream ecosystems worldwide and their interactions are of particular concern, with gaps existing in understanding stressor impacts on stream communities. Addressing these knowledge gaps will aid in targeting and designing of appropriate mitigation measures. In this study, the agricultural stressors fine sediment (ambient,...
Chapter
Ireland has a diverse physical landscape of upland and lowland inland waters represented by 13,200 km of river and 12,000 lakes framed by an estimated 3171 km of coastline providing a range of freshwater ecosystem services. The quality and quantity of water flowing through Ireland’s inland and coastal waters are determined by the complex interactio...
Article
Diffuse transfer of nitrogen (N) and phosphorus (P) in agricultural catchments is controlled by the mobilisation of sources and their delivery to receiving waters. While plot scale experiments have focused on mobilisation processes , many catchment scale studies have hitherto concentrated on the controls of dominant flow pathways on nutrient delive...
Article
Pesticide contamination of water is a potential environmental issue which may impact the quality of drinking water. The full extent of pesticide contamination is not fully understood due to complex fate pathways in the subsurface. Groundwater pesticide occurrence was investigated at seven agricultural sites in different hydrogeological settings to...
Article
Full-text available
This special issue of Ambio compiles a series of contributions made at the 8th International Phosphorus Workshop (IPW8), held in September 2016 in Rostock, Germany. The introducing overview article summarizes major published scientific findings in the time period from IPW7 (2015) until recently, including presentations from IPW8. The P issue was su...
Poster
This poster presents the preliminary findings of a research project on emerging organic contaminants in Irish karst and fractured aquifers, which contributes to current groundwater research in iCRAG (Irish Centre for Research in Applied Geosciences). The project is focussed on compounds that are widely used as anti-parasitic drugs in Irish agricult...
Article
The efficacy of water quality policies aiming to reduce or prevent nitrate contamination of waterbodies may be constrained by the inherent delay or “time lag” of water and solute transport through unsaturated (soil) and saturated (groundwater) pathways. These delays must be quantified in order to establish realistic deadlines, thresholds and policy...
Article
Full-text available
We tested an empirical modelling approach using relatively low-cost continuous records of turbidity and discharge as proxies to estimate phosphorus (P) concentrations at a sub-hourly time step for estimating loads. The method takes into account non-linearity and hysteresis effects during storm events, and hydrological conditions variability. High-f...
Article
Full-text available
Stormflow and baseflow phosphorus (P) concentrations and loads in rivers may exert different ecological pressures during different seasons. These pressures and subsequent impacts are important to disentangle in order to target and monitor the effectiveness of mitigation measures. This study investigated the influence of stormflow and baseflow P pre...
Article
Full-text available
At the catchment scale, a complex mosaic of environmental, hydrogeological and physicochemical characteristics combine to regulate the distribution of groundwater and stream nitrate (NO3(-)). The efficiency of NO3(-) removal (via denitrification) versus the ratio of accumulated reaction products, dinitrogen (excess N2) & nitrous oxide (N2O), remain...
Article
Full-text available
Defining critical source areas (CSAs) of diffuse pollution in agricultural catchments depends upon the accurate delineation of hydrologically sensitive areas (HSAs) at highest risk of generating surface runoff pathways. In topographically complex landscapes, this delineation is constrained by digital elevation model (DEM) resolution and the influen...
Article
Landscapes typically deemed at risk from leached losses of nitrogen (N) and phosphorus (P) are those with short subsurface hydrologic time lags. Due to the short time it takes nutrients to move from a source to an area of concern, such sites are deemed perfect to test the efficacy of programmes of measures as management changes. However, a small su...
Article
The responses of waterbodies to agricultural programmes of measures are frequently delayed by hydrological time lags through the unsaturated zone and groundwater. Time lag may therefore, impede the achievement of remediation deadlines such as those described in the EU Water Framework Directive (WFD). Omitting time lag from catchment characterisatio...
Article
Diffuse phosphorus (P) mitigation in agricultural catchments should be targeted at critical source areas (CSAs) that consider source and transport factors. However, development of CSA identification needs to consider the mobilisation potential of legacy soil P sources at the field scale, and the control of (micro)topography on runoff generation and...
Article
Full-text available
Identifying critical source areas (CSAs) of diffuse pollution in agricultural catchments requires the accurate identification of hydrologically sensitive areas (HSAs) at highest propensity for generating surface runoff and transporting pollutants. A new GIS-based HSA Index is presented that improves the identification of HSAs at the sub-field scale...
Article
Full-text available
Purpose This study investigated the phosphorus (P) source, mobilisation and transport potential of ditch bed sediments as well as surrounding field and bank soils in two agricultural headwater catchments with contrasting soil drainage capacities. This information is important for discerning the potential for ditches to attenuate or augment transfer...
Article
Full-text available
Managing incidental losses associated with liquid slurry applications during closed periods has significant cost and policy implications and the environmental data required to review such a measure are difficult to capture due to storm dependencies. Over four years (2010–2014) in five intensive agricultural catchments, this study used high-resoluti...