The management of nutrients in agricultural production is a critical process that can affect the environmental impact of agricultural enterprises, in terms of emissions to water and air, and their economic viability. In particular, the use of nitrogen fertilisers can result in losses of nitrate to surface and groundwater and emissions of ammonia and nitrous oxide to the atmosphere. The issue of nutrient pollution from agriculture has been an ongoing challenge. Many of the processes are well understood, but their management in the context of agricultural production is often one of trying to strike a balance between competing objectives, which can increase the complexity of decision making processes at both the farm and policy levels.
In the European Union (EU), several policies have been developed and implemented to address nutrient pollution from agriculture including Council Directive 91/676/EEC (the Nitrates Directive). Article 5 requires each Member State (MS) to develop nitrate action programme (NAP) measures. These can vary from one MS (or region) to another, thus there is scope for differences across the EU. There have been numerous previous studies on the implementation of the Nitrates Directive, which have either tended to focus on individual MSs or on specific measures or issues. However, to date there have been few detailed studies that have aimed to holistically synthesise and compare NAP measures across the EU to identify differences in implementation and potential impact. To address this, during 2019-20 the European Commission contracted the Agriculture and Environment Research Unit at the University of Hertfordshire in the UK to undertake a project titled: "Providing support in relation to the identification of approaches and measures in action programmes Directive 91/676/EEC" (Ref. ENV.D.1/SER/2018/0017). This document is the final report for this project.
The project involved the design and development of an inventory of NAP measures, associated inventory database and software, and the Nitrate Action Programme Information (NAPINFO) web application. The inventory was populated by undertaking an extensive literature review to collate information on the implementation of NAP measures in each MS. Eighty NAPs were reviewed (21 MS NAPs and 59 regional NAPs within 7 MSs); 73 NAP measures were defined (with 35 defined as core measures) containing ~13600 measure variants. These were stored in the inventory database using a range of quantitative and qualitative fields. The NAPINFO web application was populated using the inventory database and was used to facilitate a consultation with MS experts to check, amend and refine the data in the inventory. Around two-thirds (66%) of MSs responded to the consultation covering 46% of the NAPs. The information collated on NAPs came from a range of sources (written in different languages) that are subject to change over time, including during the lifetime of this project. Consequently, the inventory should be considered a 'first edition' and is essentially a snapshot of the situation within each MS/region in 2019.
The inventory software was used to interrogate the database to compare the implementation of NAP measures within each of the 80 NAPs. Twelve of the core measures are implemented in over 75% of the NAPs and majority of the measures in Annex III of the Nitrates Directive are implemented in over 90% of the NAPs. A more detailed comparison of the implementation of the measures is provided in Annex A, which also includes the findings of an extensive literature review on key processes and elements covered by each NAP measure with respect to nitrate loss and other environmental impacts (which was used to support the NAP characterisation). The analysis revealed that there is significant variability between NAPs (in terms of the measures within each NAP and how they have been implemented), but this does not necessary correlate with variation in the risk of nitrate loss, as some of the variation will be due to tailoring to regional circumstances. However, there is scope for MSs/regions to learn from each other, especially where regional pedoclimatic and agricultural circumstances are similar and where there are differences in the measures implemented.
Each NAP has been characterised with respect to its potential to reduce the risk of nitrate loss and other environmental impacts including: nitrous oxide; methane; carbon dioxide; ammonia; phosphorus; pathogens; substances with a high biochemical oxygen demand; soil erosion; biodiversity; water use; and pesticide loss. A bespoke risk-based method (drawing upon the source-pathway-receptor concept) was developed for this project that accounts for the key risk elements associated with each environmental impact and which is tailored using spatial data and statistics that account for regional variabilities including climate, geology, slope, flooding and irrigation. The characterisation process results in a Risk Mitigation Potential (RMP) class (low to high) for each NAP and each measure within the NAP. The measures are ranked based on their contribution to the overall RMP of the NAP and they are also assessed individually to identify potential for enhancement. Those measures within the inventory but not in the NAP for an MS/region have also been characterised to identify their potential as possible new measures to be implemented. The full outputs for each NAP are provided in a separate report for each MS and an Excel workbook (Annexes C1-28). The RMPs for all NAPs are also summed and presented in Annex D. Detailed analysis and insights can be found in Section 4.4 and Annexes C and D. However, as examples, the characterisation revealed that across all the NAPs measures related to fertiliser application are addressing both run-off and leaching, but have a slightly higher mitigation potential for losses of via run-off; closed periods (M30) is ranked the highest most often across all the NAPs and tends to have slightly higher mitigation potential for losses of via leaching (compared to run-off); and closed periods also contribute to reducing the risk of nitrous oxide emissions, with over half of NAPs having moderate to high mitigation potential.
The extensive literature review also collated data with respect to agricultural land use, nitrates in surface and groundwater bodies and any transboundary issues within each MS. The main purpose of this is to provide context for the outputs from the other tasks. The main outputs with regard to water quality and transboundary impacts are presented in the reports for each MS (Annexes C1-28). Summarising this information on a broad continental scale is challenging, as the aggregation processes tend to result in the loss of important detail, especially with respect to sampling points, frequencies, identification of hotspots and temporal boundaries. This is partly due fragmented data reporting, different data sources and availability. However, the data that has been summarised does provide a snapshot of the most recent concentrations monitored in each MS, the general trend and the scope for transboundary impacts.
Finally, the NAP measures have been compared to measures implemented under Directive 2016/2284, the National Emission Ceilings Directive (NECD), to identify any potential synergies and conflicts with respect impacts on emissions of nitrate and ammonia. During 2019, National Air Pollution Control Programmes were being submitted by MSs; twenty of these were available to review within the lifetime of this project, from which 31 common NECD measures were identified and added to the NAPINFO database. Synergies and conflicts were identified firstly by comparing NECD measures to NAP measures and, secondly, by examining the effect of NAP measures ammonia emissions (derived from the risk characterisation). The general conclusion is that there appears to be synergy between the NECD and the Nitrates Directive and for the few instances where a potential conflict was identified there is scope for mitigation.
It is important to note that this study did not aim to assess whether the measures are 'sufficient' with respect to meeting the requirements of the ND or for improving water quality (the RMP class does not assess this). This is because it is difficult to integrate the findings and correlate outputs from the implementation analysis; the risk characterisation process; and trends in the nitrate concentration of surface and groundwater (and any transboundary issues). The broad nature of the analyses and the data collated do not facilitate a credible or robust assessment. Correlating land use practices and interventions with changes in nitrates in surface and groundwater bodies (and any transboundary issues) needs to be done on a more detailed and localised site by site basis. However, the information presented in this project, does provide a holistic picture which could be used as a basis to identify areas where potential impacts could be explored more specifically (e.g. specific measures/interventions in specific regions or catchments).
This has been an ambitious and challenging project that has aimed to provide a broad and current picture of the implementation of NAP measures under the Nitrates Directive. The inventory of NAP measures coupled with risk characterisation; data on water quality and transboundary issues; and the analysis of synergies and conflicts with the NECD, provides a holistic overview that can be used to support the full implementation of existing legislation, policy development and to identify areas for future research.