Activities under this topic will help to progress towards the objectives of the Mission ‘A Soil Deal for Europe’, in particular to its specific objective 4, “Reduce soil pollution and enhance restoration” and the operational objective 3, “Develop an integrated EU soil monitoring system and track progress towards soil health.” Project results are expected to contribute to all of the following outcomes:

• Enhanced understanding of the sources that contribute to spatio-temporal variability in soil biogeochemical processes and in particular how these sources influence total nitrogen fluxes across major climatic conditions throughout Europe and Associated Countries.
• Advanced comprehension of the mechanisms governing nitrogen translocation from soil, including gaseous emissions and subsurface leaching into groundwater.
• More effective monitoring, reporting and verification of greenhouse gas emissions and mitigation efforts and significant reduction in the uncertainty associated with the estimates of the full nitrogen budget at the European continental scale.
• Assessment of improved nitrogen management and conservation strategies.
• Improved land managers confidence in the implementation of advanced strategic nitrogen management practices that aim at reducing nitrogen losses from soil.

Achieving climate neutrality by 2050 is a central goal of the European Green Deal. However, soil-derived gaseous nitrogen emissions from agriculture are often overlooked due to challenges in monitoring. A comprehensive assessment of both gaseous and non-gaseous nitrogen losses, including their geographical distribution and varying temporal resolution, is essential to inform effective greenhouse gas (GHG) mitigation strategies and encourage the adoption of higher Intergovernmental Panel on Climate Change (IPCC) tiers at the national level.

Nitrogen losses are highly episodic, and the current temporal and spatial resolution of information regarding nitrogen dynamics across Europe is insufficient for a comprehensive estimation of the full nitrogen budget at a continental scale. The most commonly used methodology for measuring N-flux involves discontinuous flux measurements accompanied by standard gap-filling methods, which lead to large uncertainties and biased emission factors. Additionally, most existing observations focus on temperate zones and single flux exit pathways, neglecting the full spectrum of nitrogen forms, including both gaseous and non-gaseous forms across different climatic conditions. Data and observations are particularly lacking in the Mediterranean basin and some nitrogen transformation pathways are not well investigated. For example, widely used modelling approaches estimate the reduction of N₂O to N₂ by applying a conversion factor developed in laboratory conditions that do not comprehensively represent the vast array of soil types found in Europe. These ratios are subject to bias associated with the use of linear rates for nonlinear dynamics. To address these gaps, accurate information must be acquired, which will facilitate the development of effective management strategies that effectively minimise total nitrogen losses from soil. Additionally, this information will improve the parameterization and validation of models and increase the confidence of model predictions when scaled to the continental level. This will ultimately lead to a more refined and accurate estimation of nitrogen surplus, enrich existing dashboard estimates, and further support the evaluation of the effectiveness of management strategies, and guide future research and policy decisions related to mitigation efforts.

Proposed activities should:

• Develop and employ advanced nitrogen monitoring and analytical techniques to generate high temporal resolution data on nitrogen fluxes and their drivers in various climatic conditions with particular focus on underrepresented pedo-climatic conditions.
• Implement a coordinated, holistic approach to develop and evaluate robust, practical management strategies that effectively minimise total nitrogen losses from soils while addressing potential trade-offs with other environmental concerns, such as water quality and soil carbon preservation.
• Utilise advanced modelling approaches to analyse the collected data, identify patterns and relationships between soil biogeochemical processes and nitrogen fluxes, and improve predictive tools that can be used to inform management strategies on a regional to continental scale.
• Implement and monitor pilot projects that test the effectiveness of the developed management strategies in diverse pedo-climatic zones, accounting for local environmental conditions, agricultural practices both in conventional and organic farming systems, and socio-economic factors that may influence adoption and outcomes.
• Synthesise the findings from field studies, modelling efforts, and pilot projects into a comprehensive estimation of the full nitrogen budget at the European continental scale contributing to the EU Soil Observatory through the provision of high-quality datasets for monitoring, reporting and verification.
• Development of scenarios on how climate change and land use change will affect nitrogen cycling through the soil-plant-atmosphere system.

Proposals should demonstrate a route towards open access, longevity, sustainability and interoperability of knowledge and outputs through close collaboration with the Joint Research Centre’s EU Soil Observatory (EUSO) and the project Soil-WISE. In particular, to ensure inter-operability between existing databases and models and their integration in the EUSO.

Proposals should include a dedicated task and appropriate resources to build on the work of other projects working on quantification of nitrogen fluxes in Europe that are being funded by other entities, including philanthropic organisations, particularly where there is geographical or thematic complementarity.

In this topic, the integration of the gender dimension (sex and gender analysis) in research and innovation content is not a mandatory requirement.