The limitations of bioeconomy LCA studies for understanding the transition to sustainable bioeconomy.

Purpose: Transition to bioeconomy requires all actors and stakeholders to measure the impact of systems that use bioresources and technologies to provision society. There are however some challenges with integrating LCA into business development and management, which have important implications for bioeconomy. There have been many LCA studies published in the twenty-first century, but the question must be answered: how useful are these LCA studies to help understand and manage transition to sustainable bioeconomy? Method: This research used a structured literature review to identify 83 bioeconomy LCA studies published from January 2006 to June 2021 (excluding bioenergy). The studies were analysed for compliance with the ISO 14044 standard, with specific reference to the goal, commissioning perspective, system boundary, function and functional unit, impact methods and categories. Results and discussions: It was found that more than 85% of the studies reviewed failed to present the required goal statement and a description of the function of the system. Nearly 13% of the studies did not define the system boundary, and only 17% included a full life cycle including raw material extraction, production, use and end-of-life stages. The majority of the LCA studies surveyed from 2006 to 2021 were either (i) not in compliance with the ISO standards or (ii) space and style limitations of the publication process prevented competent practitioners from properly conveying their work. This suggests that the value and integrity of the literature are undermined by not rigorously addressing the first and most important stage of an LCA study. Conclusion: When interpreting the results, a major shortcoming noted was that most studies did not consider the industrial symbiosis needed between feedstock, technology, primary products, side streams, downstream valorisation and long-term circularity in order to properly understand the transition pathways required. Bioeconomy technologies were imagined as displacers for feedstocks and processes to adapt business as usual, rather than as transformers of the system to a sustainable footing. Recommendation: If LCA studies are going to provide meaningful information for actors and stakeholders to assess whether a system will be able to operate sustainably, studies should include a full, integrated system, standards should be adhered to and approaches should perhaps go beyond mere eco-efficiency, or doing less harm, as these are not necessarily indicative of sustainability. Historical bioeconomy LCA studies do not provide great insight into the transition to sustainable bioeconomy. Supplementary information: The online version contains supplementary material available at 10.1007/s11367-022-02053-w.

Upscale fermenter design for lactic acid production from cheese whey permeate focusing on impeller selection and energy optimization.

This study focusses on the design and scale-up of industrial lactic acid production by fermentation of dairy cheese whey permeate based on standard methodological parameters. The aim was to address the shortcomings of standard scale-up methodologies and provide a framework for fermenter scale-up that enables the accurate estimation of energy consumption by suitable selection of turbine and speed for industrial deployment. Moreover, life cycle assessment (LCA) was carried out to identify the potential impacts and possibilities to reduce the operation associated emissions at an early stage. The findings showed that a 3000 times scale-up strategy assuming constant geometric dimensions and specific energy consumption (P/V w ) resulted in lower impeller speed and energy demand. The Rushton turbine blade (RTB) and LightninA315 four-blade hydrofoil (LA315) were found to have the highest and lowest torque output, respectively, at a similar P/V w of 2.8 kWm-3, with agitation speeds of 1.33 and 2.5 s-1, respectively. RTB demonstrating lower shear damage towards cells (up to 1.33 s-1) was selected because it permits high torque, low-power and acceptable turbulence. The LCA results showed a strong relation between the number of impellers installed and associated emissions suggesting a trade-off between mixing performance and environmental impacts. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05239-6.

The environmental impact of dairy production on poorly drained soils under future climate scenarios for Ireland.

The environmental impact of dairy production in Ireland has been widely studied and it is known that regional differences in management and impact are driven by climate. Climate change projections for Ireland predict increasing temperature, change in rainfall patterns and decreasing in solar radiation, varying by agroclimatic region. This study evaluated the environmental impacts of low-cost, grass-based, rotational-grazing dairy production on poorly drained soils under climate change. The Dairy_sim model was used to determine the theoretical optimum dairy system management for five different locations in Ireland assuming a poorly drained soil resource under baseline (1981-2000) and future climate scenarios (2041-2060, high and low emissions scenarios). An optimum system was defined as having maximum grass production and grazed grass in the diet, minimum necessary silage, minimum imported feed, minimum housing days and a very small silage surplus. Life cycle assessment was then used to quantify the environmental impacts (climate change, eutrophication and acidification) for all scenarios. The dairy production systems were predicted to be more productive in the future, with climate change impacts per unit milk reduced or the same, acidification impacts reduced and eutrophication impacts reduced. The absolute emissions driving climate change and eutrophication were predicted to significantly increase for the future low emission scenario, and emissions driving acidification were predicted to slightly increase. The predictions indicate that system adaptation to mitigate absolute emissions are needed rather than just policies that focus on impacts per unit output.

Biochar, compost and biochar-compost blend as options to recover nutrients and sequester carbon.

This work assessed the potential environmental impact of recycling organic materials in agriculture via pyrolysis (biochar) and composting (compost), as well its combination (biochar-compost blend) versus business-as-usual represented by mineral fertiliser. Life cycle assessment methodology was applied using data sourced from experiments (FP7 project Fertiplus) in three countries (Spain, Italy and Belgium), and considering three environmental impact categories, (i) global warming; (ii) acidification and (iii) eutrophication. The novelty of this analysis is the inclusion of the biochar-compost blend with a focus on multiple European countries, and the inclusion of the acidification and eutrophication impact categories. Biochar, compost and biochar-compost blend all resulted in lower environmental impacts than mineral fertiliser from a systems perspective. Regional differences were found between biochar, compost and biochar-compost blend. The biochar-compost blend offered benefits related to available nutrients and sequestered C. It also produced yields of similar magnitude to mineral fertiliser, which makes its acceptance by farmers more likely whilst reducing environmental impacts. However, careful consideration of feedstock is required.

The effect of lameness on the environmental performance of milk production by rotational grazing.

Dairy production leads to significant environmental impacts and increased production will only be feasible if the environmental performance at farm level permits a sustainable milk supply. Lameness is believed to become more prevalent and severe as herd sizes increase, and can significantly reduce milk output per cow while not influencing other attributes of the production system. The objective of this work was to quantify the effect of lameness on the environmental performance of a typical grazed grass dairy farm and evaluate the theoretical value of sensor-based real-time lameness management. Life cycle assessment was used to compare a typical baseline farm with scenarios assuming increased lameness severity and prevalence. It was found that lameness could increase the farm level global warming potential, acidification potential, eutrophication potential and fossil fuel depletion by 7-9%. As increased herd sizes will increase cow: handler ratio, this result was interpreted to suggest that the use of sensors and information and communication technology for lameness detection could improve management on dairy farms to reduce the adverse impact on environmental performance that is associated with lameness.

An environmental analysis of options for utilising wasted food and food residue.

The potential environmental impact of wasted food minimisation versus its utilisation in a circular bioeconomy is investigated based on a case study of Ireland. The amount of wasted food and food residue (WFFR) produced in 2010 was used for business-as-usual, (a) and four management options were assessed, (b) minimisation, (c) composting, (d) anaerobic digestion and (e) incineration. The environmental impacts Global Warming Potential (GWP), Acidification Potential (AP) and Eutrophication Potential (EP) were considered. A carbon return on investment (CRoI) was calculated for the three processing technologies (c-e). The results showed that a minimisation strategy for wasted food would result in the greatest reduction of all three impacts, -4.5 Mt CO2-e (GWP), -11.4 kt PO43-e (EP) and -43.9 kt SO2-e (AP) compared to business as usual. For WFFR utilisation in the circular bioeconomy, anaerobic digestion resulted in the lowest environmental impact and best CRoI of -0.84 kg CO2-e per Euro. From an economic perspective, for minimisation to be beneficial, 0.15 kg of wasted food would need to be reduced per Euro spent.

Soil organic carbon across scales.

Mechanistic understanding of scale effects is important for interpreting the processes that control the global carbon cycle. Greater attention should be given to scale in soil organic carbon (SOC) science so that we can devise better policy to protect/enhance existing SOC stocks and ensure sustainable use of soils. Global issues such as climate change require consideration of SOC stock changes at the global and biosphere scale, but human interaction occurs at the landscape scale, with consequences at the pedon, aggregate and particle scales. This review evaluates our understanding of SOC across all these scales in the context of the processes involved in SOC cycling at each scale and with emphasis on stabilizing SOC. Current synergy between science and policy is explored at each scale to determine how well each is represented in the management of SOC. An outline of how SOC might be integrated into a framework of soil security is examined. We conclude that SOC processes at the biosphere to biome scales are not well understood. Instead, SOC has come to be viewed as a large-scale pool subjects to carbon flux. Better understanding exists for SOC processes operating at the scales of the pedon, aggregate and particle. At the landscape scale, the influence of large- and small-scale processes has the greatest interaction and is exposed to the greatest modification through agricultural management. Policy implemented at regional or national scale tends to focus at the landscape scale without due consideration of the larger scale factors controlling SOC or the impacts of policy for SOC at the smaller SOC scales. What is required is a framework that can be integrated across a continuum of scales to optimize SOC management.

A review of nitrous oxide mitigation by farm nitrogen management in temperate grassland-based agriculture.

Nitrous oxide (N2O) emission from grassland-based agriculture is an important source of atmospheric N2O. It is hence crucial to explore various solutions including farm nitrogen (N) management to mitigate N2O emissions without sacrificing farm profitability and food supply. This paper reviews major N management practices to lower N2O emission from grassland-based agriculture. Restricted grazing by reducing grazing time is an effective way to decrease N2O emissions from excreta patches. Balancing the protein-to-energy ratios in the diets of ruminants can also decrease N2O emissions from excreta patches. Among the managements of synthetic fertilizer N application, only adjusting fertilizer N rate and slow-released fertilizers are proven to be effective in lowering N2O emissions. Use of bedding materials may increase N2O emissions from animal houses. Manure storage as slurry, manipulating slurry pH to values lower than 6 and storage as solid manure under anaerobic conditions help to reduce N2O emissions during manure storage stage. For manure land application, N2O emissions can be mitigated by reducing manure N inputs to levels that satisfy grass needs. Use of nitrification inhibitors can substantially lower N2O emissions associated with applications of fertilizers and manures and from urine patches. N2O emissions from legume based grasslands are generally lower than fertilizer-based systems. In conclusion, effective measures should be taken at each step during N flow or combined options should be used in order to mitigate N2O emission at the farm level.

Biocircularity: a Framework to Define Sustainable, Circular Bioeconomy.

Bioeconomy is proposed as a solution to reduce reliance on fossil resources. However, bioeconomy is not always inherently circular and can mimic the conventional take, make, consume, dispose linear economic model. Agricultural systems will be relied on to provide food, materials, and energy, so unless action is taken, demand for land will inevitably exceed supply. Bioeconomy will have to embrace circularity to enable production of renewable feedstocks in terms of both biomass yield and maintaining essential natural capital. The concept of biocircularity is proposed as an integrated systems approach to the sustainable production of renewable biological materials focusing on extended use, maximum reuse, recycling, and design for degradation from polymers to monomers, while avoiding the "failure" of end of life and minimizing energy demand and waste. Challenges are discussed including sustainable production and consumption; quantifying externalities; decoupling economic growth from depletion; valuing natural ecosystems; design across scales; renewable energy provision; barriers to adoption; and integration with food systems. Biocircularity offers a theoretical basis and measures of success, for implementing sustainable circular bioeconomy.

Assessment of the Environmental Impact of Food Consumption in Ireland-Informing a Transition to Sustainable Diets.

Dietary changes are required to mitigate the climatic impact of food consumption. Food consumption databases can support the development of sustainable food based dietary guidelines (SFBDG) when linked to environmental indicators. An improved knowledge base is crucial to the transition to sustainable diets, and multiple environmental indicators should be considered to ensure this transition is evidence based and accounts for trade-offs. The current study aimed to quantify the environmental impact of daily diets across population groups in Ireland. Nationally representative food consumption surveys for Irish children (NCFSII; 2017-2018), teenagers (NTFSII; 2019-2020), and adults (NANS; 2008-2010) were used in this analysis. Blue water use (L) and greenhouse gas emissions (GHGe; kgCO2eq) were assigned at food level to all surveys. Cropland (m2), nitrogen (kgN/t), and phosphorous use (kgP/t) were assigned at the agricultural level for adults. Multiple linear regressions, Spearman correlations, and ANCOVAs with Bonferroni corrections were conducted. Higher environmental impact diets were significantly associated with demographic factors such as age, education status, residential location, and sex, but these associations were not consistent across population groups. The median greenhouse gas emissions were 2.77, 2.93, and 4.31 kgCO2eq, and freshwater use per day was 88, 144, and 307 L for children, teenagers, and adults, respectively. The environmental impact of the Irish population exceeded the planetary boundary for GHGe by at least 148% for all population groups, however the boundary for blue water use was not exceeded. Meat and meat alternatives (27-44%); eggs, dairy, and dairy alternatives (15-21%); and starchy staples (10-20%) were the main contributors to GHGe. For blue water use, the highest contributors were meat and meat alternatives in children; savouries, snacks, nuts, and seeds in teenagers; and eggs, dairy, and dairy alternatives in adults (29-52%). In adults, cropland use, nitrogen use, and phosphorous use exceeded planetary boundaries by 277-382%. Meat, dairy, and grains were the main contributors to cropland, nitrogen, and phosphorous use (79-88%). The quantified environmental impact of Irish diets provides a baseline analysis, against which it will be possible to track progress towards sustainable diets, and the basis for the development of Sustainable Food Based Dietary Guidelines in Ireland.

The effects of grazer exclosure duration on soil microbial communities on the Qinghai-Tibetan Plateau.

While determining the response of soil microbes to grazer exclosure duration is critical to understanding ecosystem restoration processes, few studies have focused on this issue. With seasonal grazing as a control, microbes of alpine grassland soils under 5, 13, 22, and 39 years of grazer exclosure situated in the eastern part of the Qinghai-Tibetan Plateau, were examined. Microbial diversity was determined through Illumina high-throughput sequencing of the 16S rRNA gene and an internal transcription spacer (ITS). We found that soil bacterial α-diversity showed insignificant differences between seasonal grazing and grazer exclosure and among the grazer exclosures of different durations, while fungal α-diversity under the 5-year grazer exclosure was significantly different from those under the other treatments. Soil microbial community profiles under the 13-, 22-, and 39-year grazer exclosures were significantly different compared to those under the seasonal grazing or 5-year grazer exclosure. Briefly, longer exclosure durations led to a higher relative abundance of multiple copiotrophic microbial lineages (e.g., ß-Proteobacteria, Rhizobiales, and Frankiales), whereas several oligotrophic microbial lineages (e.g., Chloroflexi, Leotiomycetes, and Xylariales) gradually and significantly decreased. Functional predictions suggest that as grazer exclosure duration was extended, the relative abundance of nitrogen fixers increased, while the proportions of plant pathogenic fungi decreased. This indicates that long-term grazer exclosure duration may contribute to enhanced soil nitrogen fixation and grassland health by maintaining plant growth and decreasing the risk of plant disease. However, this may have a resource cost as plant productivity and soil organic carbon both decreased with the extension of grazer exclosure duration. Therefore, the agroecology effect of grazer exclosure duration on the diversity and abundance of soil nitrogen fixing bacteria and plant pathogen fungi, should be given more attention in the cold and humid portion of the Qinghai-Tibetan Plateau.

An evaluation of life cycle assessment of European milk production.

Life cycle assessment (LCA) is a method regulated by ISO that conveys the environmental impact of products. LCA studies of the same product should be comparable to benefit environmental policy making. LCA of milk production has evaluated environmental issues such as greenhouse gas emissions, resource utilisation and land use change. Thirteen LCA studies of European milk production were analysed for comparability, and direct comparison was difficult due to technical issues, arbitrary choices and inconsistent assumptions. The strengths and weaknesses of LCA for evaluating an agricultural system are identified and improvements for comparability of future studies are also considered. Future LCA of milk production should ensure that: (1) the production system is appropriately characterized according to the goal of study; (2) a clear description of the system boundary and allocation procedures is provided according to ISO standards; (3) a common functional unit, probably Energy Corrected Milk, should be used or assumed fat and protein content presented to enable comparisons; (4) where appropriate, site-specific emission factors and characterization factors should be used in environmental hotspots (e.g. manure management, spreading of synthetic fertilizer, production of purchased feed), and phosphorous loss should be better addressed; (5) a range of impact categories including climate change, energy use, land use, acidification and eutrophication should be used to assess pollution swapping, all of which are subject to national or regional directives; perhaps in the future biodiversity should also be included; and (6) the sensitivity to choices of methods and uncertainty of final results should be evaluated.

Environmental impacts of animal-based food supply chains with market characteristics.

Animal-based food supply chains lead to significant environmental impacts, which can be influenced by production systems, distribution networks and consumption patterns. To develop strategy aimed at reducing the environmental impact of animal-based food supply chains, the common environmental hotspots among different types of food, the role of transport logistics and the consequence of end market need to be better understood. Life cycle assessment was adopted to model three types of animal-based food chains (beef, butter and salmon), with specific technologies, high spatial-resolution logistics and typical consumption patterns for three markets: local, regional (intra-European) and international. The results confirmed that the farm production stage usually had the greatest environmental impact, except when air transport was used for distribution. Potentially, the role of end market also can significantly influence the environmental impacts. To understand more, three improvement options were examined in detail with regard to hotspots for climate change: novel feed ingredients (farm production stage), sustainable aviation fuel (transport and logistics stage) and reduction of wasted food (consumption and end of life stage). Significant reduction was achieved in the salmon system by sustainable aviation fuel (64%) and novel feed (15%). Minimizing food waste drove the greatest reduction in the beef supply chain (23%) and the international butter supply chain can reduce 50% of GHG mission by adopting sustainable aviation fuel. Combined interventions could reduce GHG emission of animal-based food supply chains by 15% to 82%, depending on market, transport and food waste behaviour. The results show that eco-efficiency information of animal-based foods should include the full supply chain. The effective mitigation strategy to achieve the greatest reduction should not only consider the impacts on-farm, but also detail of the downstream impacts, such as food distribution network and consumption patterns.

Hybrid life cycle assessment of agro-industrial wastewater valorisation.

Wastewater from food processing facilities can have high nutrient valorisation potential. Valorising sugar-rich agro-industrial wastewater may have significant impacts on sustainability of wastewater treatment plant (WWTP). The objective of this study is to evaluate the environmental, economic and social impacts of a novel wastewater valorisation technology. This technology is designed to produce single cell protein (SCP) from wastewater of a fruit juice processing facility. To evaluate the comprehensive sustainability impacts on WWTP and overall background economy, a hybrid life cycle assessment model was developed by combining the multi-regional input-output database (Exiobase) with process-based life cycle inventories of conventional and AgroCycle WWTP. The results indicated the upstream impacts of wastewater could have significant influence on sustainability of WWTP with nutrient valorisation. Therefore the 'zero burden assumption' should not be adopted for upstream wastewater. For the sustainability performance, valorising nutrients from WWTP with AgroCycle technology can improve the environmental performance of WWTP. However, the positive social-economic impacts were directly associated with WWTP system, not the whole background economy. The production of SCP could reduce the Gross Value Added (GVA) and employment in the 'oil seeds sector'. In order to improve the social-economic impacts and promote a circular bioeconomy model in the fruit juice sector, further development is required to improve valorisation productivity and create a better value chain for valorised products.

Bridging environmental and financial cost of dairy production: A case study of Irish agricultural policy.

The Irish agricultural policy 'Food Harvest 2020' is a roadmap for sectoral expansion and Irish dairy farming is expected to intensify, which could influence the environmental and economic performance of Irish milk production. Evaluating the total environmental impacts and the real cost of Irish milk production is a key step towards understanding the possibility of sustainable production. This paper addresses two main issues: aggregation of environmental impacts of Irish milk production by monetization, to understand the real cost of Irish milk production, including the environmental costs; and the effect of the agricultural policy 'Food Harvest 2020' on total cost (combining financial cost and environmental cost) of Irish milk production. This study used 2013 Irish dairy farming as a baseline, and defined 'bottom', 'target' and 'optimum' scenarios, according to the change of elementary inputs required to meet agricultural policy ambitions. The study demonstrated that the three monetization methods, Stepwise 2006, Eco-cost 2012 and EPS 2000, could be used for aggregating different environmental impacts into monetary unit, and to provide an insight for evaluating policy related to total environmental performance. The results showed that the total environmental cost of Irish milk production could be greater than the financial cost (up to €0.53/kg energy corrected milk). The dairy expansion policy with improved herbage utilization and fertilizer application could reduce financial cost and minimize the total environmental cost of per unit milk produced.

Environmental impacts of alternative agricultural uses of poorly drained farm land in Ireland.

Abolition of the milk quota in the European Union and favourable market conditions have stimulated the expansion of the dairy sector in Ireland, causing more milk to be produced from poorly drained land. This work evaluated the environmental impacts of alternative agricultural uses for poorly drained farm land in Ireland using life cycle assessment (LCA). The avoided burden of the displaced product was used to calculate the net environmental consequences in the context of regional or global markets. The impact categories evaluated were climate change, eutrophication and acidification, all expressed per hectare of land for the alternative land uses, which were pasture-based milk, suckler beef and lowland sheep production and coniferous forestry. Beef had the lowest net climate change impact with global marginal and average product substitution while sheep had the lowest net climate change impact with European displaced product. For net eutrophication and acidification, dairy had the lowest impacts with European and global average displaced product. With global marginal displaced product, forestry had the lowest net eutrophication impact and sheep had the lowest net acidification impact. From an Irish perspective, forestry would generate the lowest environmental impacts and would also increase soil carbon stock, but this was not the best land use option from global perspective. Overall it can be concluded that a pasture based dairy or sheep system would have the greatest net global impact reduction (i.e. greatest global benefit) as land use options for farms with poorly drained soils. Prioritizing climate change, suckler beef system would perhaps be more favourable. It is clear that the choice of the displaced regional or global co-product from the market has a great influence on the results and there is a need to consider more detailed consumption modelling to better understand the substitution process.

Review of the sustainability of food systems and transition using the Internet of Food.

Many current food systems are unsustainable because they cause significant resource depletion and unacceptable environmental impacts. This problem is so severe, it can be argued that the food eaten today is equivalent to a fossil resource. The transition to sustainable food systems will require many changes but of particular importance will be the harnessing of internet technology, in the form of an 'Internet of Food', which offers the chance to use global resources more efficiently, to stimulate rural livelihoods, to develop systems for resilience and to facilitate responsible governance by means of computation, communication, education and trade without limits of knowledge and access. A brief analysis of the evidence of resource depletion and environmental impact associated with food production and an outline of the limitations of tools like life cycle assessment, which are used to quantify the impact of food products, indicates that the ability to combine data across the whole system from farm to human will be required in order to design sustainable food systems. Developing an Internet of Food, as a precompetitive platform on which business models can be built, much like the internet as we currently know it, will require agreed vocabularies and ontologies to be able to reason and compute across the vast amounts of data that are becoming available. The ability to compute over large amounts of data will change the way the food system is analysed and understood and will permit a transition to sustainable food systems.

Monitoring of freshwater toxins in European environmental waters by using novel multi-detection methods.

Monitoring the quality of freshwater is an important issue for public health. In the context of the European project µAqua, 150 samples were collected from several waters in France, Germany, Ireland, Italy, and Turkey for 2 yr. These samples were analyzed using 2 multitoxin detection methods previously developed: a microsphere-based method coupled to flow-cytometry, and an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. The presence of microcystins, nodularin, domoic acid, cylindrospermopsin, and several analogues of anatoxin-a (ATX-a) was monitored. No traces of cylindrospermopsin or domoic acid were found in any of the environmental samples. Microcystin-LR and microcystin-RR were detected in 2 samples from Turkey and Germany. In the case of ATX-a derivatives, 75% of samples contained mainly H2 -ATX-a and small amounts of H2 -homoanatoxin-a, whereas ATX-a and homoanatoxin-a were found in only 1 sample. These results confirm the presence and wide distribution of dihydro derivatives of ATX-a toxins in European freshwaters. Environ Toxicol Chem 2017;36:645-654. © 2016 SETAC.

Phenoxyalkanoic acid herbicide sorption and the effect of co-application in a Haplic Cambisol with contrasting management.

The adsorption and desorption behaviour of two phenoxyalkanoic acid herbicides (MCPA and mecoprop-p) in a Haplic Cambisol with tillage and grassland management was examined using a batch equilibrium method. Additionally, the effect on adsorption of the simultaneous presence of the two herbicides was also studied. The sorption equilibrium was reached within 24h for adsorption and desorption in both soils. The experimental sorption data for MCPA and mecoprop-p fitted the Freundlich and the linear adsorption isotherms very well (R(2)>0.99). The Freundlich exponent values of the adsorption isotherm ranged from 0.91 to 0.98 indicating a non-linear and a linear adsorption of the two chemicals studied. Generally, mecoprop-p showed lower adsorption than MCPA, although the adsorption of both phenoxyalkanoic acid herbicides was low. The adsorption process was not fully reversed during one washing cycle, as the K(f) values for desorption were greater than corresponding K(f) values for adsorption. The Freundlich exponent (1/n) of the MCPA adsorption isotherm was affected by the simultaneous presence of both herbicides and tended more towards non-linearity, whilst the mecoprop-p adsorption exponent remained unaltered. The Freundlich and the linear adsorption coefficients calculated in the mix study were not that different from the adsorption coefficients calculated in the single compound study, and therefore single compound adsorption data can be used when modelling the fate of simultaneously applied phenoxyalkanoic acid herbicides. The study also indicated that both herbicides were poorly sorbed by the soils studied, and therefore may pose a risk of surface and/or groundwater pollution in Ireland.

Comparison of pesticide leaching potential to groundwater under EU FOCUS and site specific conditions.

The EU FOCUS scenarios are a set of nine standard scenarios based on a combination of crop, soil and weather data used throughout Europe to evaluate the leaching potential of pesticides to groundwater. In Ireland, two predefined EU FOCUS scenarios (Okehampton and Hamburg) appear to be the most appropriate to Irish conditions. However, there is concern that these scenarios may not accurately represent Irish specific conditions, especially in terms of soil and climatic weather. Therefore, the objective of this study was to parameterise a number of site specific locations in Ireland (represented by Oakpark, Clonroche, Rathangan and Elton series soils) and to compare simulated leachate levels at these locations to EU FOCUS scenarios using the PELMO (Pesticide Leaching Model) simulation model. The hydrological processes were validated using observed data for soil tension and leachate. The appropriate EU FOCUS scenarios were then simulated for the given locations and compared to the parameterised scenario. All scenarios were run using the same version of PELMO, therefore eliminating any software impacts. The models were run for 26 years using appropriate meteorological data. The results showed significant difference between the parameterised model pesticide leaching and that resulting from the EU FOCUS scenarios, the latter overestimating site pesticide leaching from 42 to 99%. The results indicated a significant conservatism in using EU FOCUS scenarios to determine potential pesticide concentration in the leachate under Irish specific conditions and ensure the desired level of protection against pesticide contamination of national water resources.