Global food security is under increasing pressure due to climate change-induced environmental stressors: salinization, droughts, and waterlogging (SDAW). These stressors are already causing economic losses, environmental degradation, and societal problems. One promising adaptation strategy involves the transition to more resilient agricultural systems based on crop selection and management, referred to in this study as Salt-Resilient Agricultural Systems (SRAS). However, current knowledge about SRAS transitions is often based on single aspects, limited in scope, and mostly focused on global scales.
A practical spatial approach is needed that combines SRAS knowledge with local data, helping decision-makers understand which SRAS options are feasible, where they are suitable, and what their implementation implies for key stakeholders. This was achieved by answering the question: ‘Which salt-resilient agricultural systems are potentially suitable for areas increasingly affected by salinization, drought, and waterlogging, and how can their spatial suitability be assessed and interpreted based on soil types and climate projections?’
To address this question, the case study Schouwen-Duiveland was investigated, because this region is already exposed to SDAW stressors. Both current conditions and a high 2050 climate scenario were assessed. This desk study developed a spatial suitability framework to evaluate the potential of SRAS based on four key factors: salinity levels, drought stress, waterlogging stress, and soil type.
Through a combination of literature review and geospatial analysing in QGIS, three promising SRAS approaches were identified for Schouwen-Duiveland. These include: 1.) Salt-tolerant crop rotation, which adapts conventional agricultural practices to include crops with higher salinity tolerance. 2.) Halophyte (plants that thrive on saline soils) intercropping or rotation, which can improve soil health by taking up salt from the soil while enabling cultivation of conventional crops. 3.) Agroforestry, a system based on trees or shrubs, which provides a higher tolerance to both drought and waterlogging, while also increasing biodiversity and potentially total yields.
Due to several data and knowledge gaps, assumptions had to be made, which reduce the robustness of the outcomes. Therefore, this study should be seen as an exploratory assessment rather than a set of definitive guidelines. Nevertheless, the results highlight the potential of these systems and emphasize the need for sustainable water management and location-specific guidelines, considering the local variability of stressors.
The spatial suitability maps were interpreted from both scientific and societal perspectives and are recognized as a tool to initiate social dialogue around the SRAS transition. These spatial guidelines can serve as practical tools for both policymakers and farmers.
Achieving a full transition requires increasing the readiness for change, starting with small-scale field experiments initiated by farmers, supported by policymakers who share the risks. Other key aspects include collaboration and knowledge sharing between stakeholders, which are essential for gaining further insights and improving spatial suitability assessment.
Despite its limitations, this study provides a foundation for a practical tool to assess local SRAS suitability. It contributes to informed discussions for SRAS transitions and ultimately supports the development of climate-resilient agriculture that strengthens long-term food security. ... Read more

This thesis critically investigates the role of BoerenNatuur, as a network of environmental cooperatives in the Netherlands, in contributing to wider-EU sustainability targets and examining the pathways through which its role could be further institutionalised within collective agri-environmental governance. The study is situated within the broader discourse on decentralised and participatory governance models, revealing a persistent gap between rhetorical support and institutional practice. By employing a qualitative case study approach, drawing on thirteen semi-structured interviews and extensive literature review, this study explores how BoerenNatuur translates policy goals into territorially embedded action. Furthermore, the study develops an analytical framework, that is used to guide the research process and facilitates five major analytical categories: 1) challenges, 2) success factors, 3) environmental and socio-economic contributions, 4) enabling conditions, and 5) pathways for institutional development. The results demonstrate that while BoerenNatuur successfully facilitates collective ecological management, its role remains institutionally underleveraged. Furthermore, respondents express divergent views on the prospects of further institutionalisation, highlighting a core tension between the need for more institutionalised support and the preservation of autonomy, informality and trust-based governance. A key finding is that BoerenNatuur’s value lies not in full regime integration, but in its hybrid and adaptive positioning across governance levels. Overall, this study’s findings contribute to a more pluralistic understanding of institutional change in environmental governance, underscoring the importance of hybrid and locally grounded governance models in navigating contested sustainability transitions. ... Read more

This thesis investigates how the Grondstoffenstation, a Circular Community Initiative in the Afrikaanderwijk in Rotterdam, creates multiple forms of value and how this value creation can be structurally supported by policy and governance frameworks. The study uses a Participatory Action Research approach and participatory observation, interviews, content analysis, and a focus group as it methods. It was explored which ecological, social, cultural, aesthetic, and financial values are contributed by the GSS to the Afrikaanderwijk. Through the Circular Value Flower (CVF) framework, these values are mapped across stakeholder groups, highlighting diverse perspectives and practices based in co-operation. The research demonstrates that while some values can be meaningfully quantified, others are best conveyed through qualitative narratives. The findings show that structural and bureaucratic barriers hinder long-term collaboration between initiatives and public institutions, despite alignment in objectives. The thesis concludes that initiatives like the GSS should be regarded not merely as temporary projects, but as public service providers and as agents for public value contestation. Recognising their broader societal impact requires more inclusive, long-term, and value-driven policy approaches. ... Read more

The agricultural sector in South Holland is highly productive and contributes greatly to the economy. However, current industrial agricultural practices generated several severe environmental and socio-economic challenges. Various renowned international institutions have emphasised the necessity for a radical, rather than an incremental, transformation in the agri-food system. There are growing calls to shift the paradigm from industrial agriculture to agroecology. Agroecology is a fundamental alternative vision of the agri-food system, bundling the power of sustainable farming practices that utilise ecological principles and re-establish the connection between farmers and consumers, and by extension nature. This study sets out to introduce the reader to agroecology and to discover strategies for how the province of South Holland can stimulate the transition to agroecology. To achieve this goal, the research methodology comprised a literature review and semi-structured interviews with agroecological farmers, an agroecology expert, and a provincial agricultural policymaker. The results uncovered that the underlying goal of the agri-food system should be transformed from profit and production maximisation of industrial agriculture to sustainability and social justice of agroecology. Achieving this goal shift requires fundamental changes and will be a tremendous challenge because of the complex and embedded nature of the agri-food system. Agroecology simultaneously tries to realise this transformation on three fronts: as a science, a set of agricultural practices, and a movement. Furthermore, the research identified key barriers and enablers in the transition to agroecology in South Holland from the agroecological farmers’ perspective. The province of South Holland could stimulate the transition by providing long-term affordable land, revising regulations to support forward-thinking practices, adopting an integrated approach to agriculture, bridging the gap between civil servants, farmers, and consumers, restructuring subsidy allocation, and lobbying to simplify (organic) certification processes. The research verifies the results of previous studies on several barriers and enablers but distinguishes itself by focusing specifically on the farmers’ perspective and the province of South Holland. Additional research is needed to broaden the scope beyond the viewpoint of agroecological farmers, and how to implement the policy recommendations effectively. Currently, the Dutch agri-food system is not yet ready for a paradigm shift from industrial agriculture to agroecology. However, the system is being pressured from various angles generating windows of opportunity. While being just one actor in the agri-food system, the province of South Holland could stimulate the development of agroecology by incorporating agroecology explicitly in policymaking. ... Read more

The research focuses on a novel measurement-based approach to estimate the farm-specific ammonia emission potential (AEP) in the dairy sector. By measuring and evaluating the feed-manure chain, feed management strategies and manure parameters influencing AEP can be identified. Ammonia emissions from dairy farms are not only considered to be an important driver of biodiversity loss, but are also responsible for nutrient losses in the farm cycle. Currently, farm-specific ammonia emissions are calculated using the Kringloopwijzer model, which tends to over- or underestimate actual ammonia emissions. Therefore, the possibilities of a measurement-based approach are evaluated.

This study analyses the relationships within the feed-manure-AEP sequence. A comprehensive approach is used, involving 23 manure parameters and 12 feed management parameters. The most important predictors of the AEP include N, TAN, Norg, N90, and the C/N ratio, whilst urea in milk, pH, and DS showed low significance. Silage maize and VEM are identified as feed management parameters with a positive indirect relationship with the AEP, whereas other roughage and fresh grass exhibit a negative indirect relationship. The calculated TAN value plays a central role in the emission calculations of the Kringloopwijzer model. There are concerns about the accuracy of this value as well as the absence of other manure parameters in the calculation, highlighting the need for further research. Currently, it is uncertain whether the AEP measurements will be suitable for an emissions-based policy, due to the incapacity to directly represent actual ammonia emissions and the uncertainty regarding the interpretation of the results caused by the period prior to the measurements. Nonetheless, the measurements are valuable in assessing the influence of the manure composition on the AEP, and how it has been affected by feed management strategies. ... Read more

The emission of reactive nitrogen species increased rapidly in the twentieth century causing a significant perturbation of the nitrogen cycle. This causes many detrimental effects for both humans and ecosystems such as eutrophication, acidification and biodiversity loss. Ammonia, which is a reactive nitrogen species is difficult to quantify because the compound is hard to observe with measurement equipment such as ground-based measurement stations and remote sensing instruments such as CrIS. Therefore, this thesis aims to improve the monitoring of surface ammonia concentrations with a machine learning technique called random forests (RF). These type of models can detect complex and non-linear relationships between variables and are frequently used in other air pollution studies. In this study, a RF model has been built to estimate the ammonia surface concentration with vertical column density (VCD) datasets, meteorological variables and land-use variables. Different combinations of VCD datasets (either modelled or CrIS VCD data) have been used to train the model and to predict the surface ammonia concentration. The result of the study is that RF models are statistically more accurate at estimating the surface ammonia concentration than the LOTOS-EUROS model when validated by ground-based measurements stations from the MAN and LML network. Especially trained RF models that have been supplied with CrIS VCD data during the prediction phase show strong performance. Moreover, when comparing the RF model that has been trained without VCD data to the ‘complete’ RF models, the complete RF models show better performance, proving the added benefit of incorporating satellite data in RF modelling. Recommendations for further research include performing similar experiments with other input variables and other machine learning algorithms, validating the performance of the RF model in different years and considering using other datasets as the ground-truth variable for RF models – such as ground-based measurement data from MAN and LML. ... Read more