A nexus approach can support the transition to sustainability by addressing trade-offs and pursuing synergies to improve water, energy, and food security. In this paper, a participatory system dynamics model was developed to identify and assess the key interlinkages between water, food, and energy in Andalusia (Spain). A panel of relevant stakeholders contributed to all stages of the model’s development. Further, by calibrating the model to CAPRI-Water projections until 2050, the evolution of the system under a plausible climate scenario, as well as effects of water prices changes, was evaluated. The results revealed a close link between water cost, irrigation water use, energy consumption, and the economic development of agriculture in the region. Large variability was observed in the effects of water pricing policies across crops. This paper concludes that a participatory system dynamics model can help in understanding the nexus synergies and can support the design of more coherent sustainability strategies in the region.

Contaminated food chain is a serious contender for arsenic (As) uptake around the globe. In Nadia, West Bengal, we trace possible means of transfer of As from multiple sources reaching different trophic levels, and associated seasonal variability leading to chronic As uptake. This work considers possible sources-pathways of As transfer through food chain in rural community. Arsenic concentration in groundwater, soil, rice, and vegetable-samples collected detected in different harvest seasons of 2014 and 2016. Arsenic level in shallow groundwater samples ranged from 0.1 to 354 µg/L, with 75% of the sites above the prescribed limit by WHO (10 µg/L) during the boro harvest season. High soil As content (∼20.6 mg/kg), resulted in accumulation of As in food crops. A positive correlation in As conc. with increase over period in all sites indicating gradual As accumulation in topsoil. Unpolished rice samples showed high As content (∼1.75 mg/kg), polishing reduced 80% of As. Among vegetables, the plant family Poaceae with high irrigation requirements and Solanaceae retaining high moisture, have the highest levels of As. Contaminated animal fodder (Poaceae) and turf water for cattle are shown to contaminate milk (0.06 to 0.24 µg/L) and behoves strategies, practices to minimize As exposure.

Regions affected by resource scarcity, poverty, and land-use conflicts need to advocate the merits of practices strongly grounded in sustainable land management. This review paper provides an analysis of agroforestry as an integrated system embedded in complex relations between resource uses in the Water–Energy–Land–Food (WELF) nexus. Using the African Sahel region as a case study, the paper explains the need for understanding land management practices, such as agroforestry, through the lens of trade-offs and benefits inherent in the WELF nexus. Agroforestry practices are demonstrated to be valuable interventions leading to i) resilience to climate stresses, ii) water, energy, and food securities, iii) mitigation of resource-oriented harbingers of conflicts and iv) development opportunities. These goals can also yield valuable results in terms of promoting sustainable development, i.e. functional ecosystems, livelihoods, and human security. Two overarching sub-nexuses, namely agroforestry–food–energy and agroforestry–food–water–climate, are identified in the Sahelian context and conceptualized. Primarily, the trade-offs outlined within these sub-nexuses are fuelwood vs. crops, use of land for more forests vs. more cropping, and water availability for agroforestry vs. agroforestry impacts on the water cycle. Despite the positive outcomes and opportunities, agroforestry systems in the Sahel still face some challenges such as vague land use rights, inadequate capacities and lack of investments. Policy recommendations are synthesized at three levels. This synthesis involves remedies to lessen pressures at the interlinks of WELF resource use, overarching remedies in the two sub-nexuses, and remedies across all the sectors and issues for improving agroforestry outcomes. Optimal remedies stress the importance of choosing the right land, water and plant combinations as well as incorporating efficiency measures and alternative sources. A successful agroforestry system is characterized by a conducive environment at the farm level in terms of institutions, management, enhancing the farmer's capacity, and good infrastructure.

Sustainable Land and Water Management (SLWM) comprises a suite of technologies and practices crucial in promoting land, water, biodiversity and environmental management to ensure their long-term potential while sustaining ecosystem services and livelihoods. This policy document provides essential information regarding land use and water resources in Africa and their relation to climate change mitigation. It provides principles of best practices guidelines for SLWM along with pathways for scaling up practices to counter effects of extreme weather. Experience shows that SLWM can enhance food security and reduce poverty while helping to adapt to and mitigate climate change.

Sustainable nutrition (SN) considers the environmental impact of food production. This study aims to analyse the relationship between nutrient density and water footprint (WF) of the most consumed food items in Hungary and to create a classification of nutrients. Based on a comprehensive analysis of literature and different data sources, the authors analysed the stochastic relationship between WF and nutrient density of different food items by Spearman's rank correlation. The analysis proved significant (P<0.05) relationship between nutrient density and WF of the most relevant food items in Hungary. Based on the classification, there are nutrients that are overconsumed among the Hungarian population and positively correlate with WF (e.g., cholesterol) and there are nutrients that are under-consumed among the Hungarian population and negatively correlate with WF (e.g., dietary fibres). In general, it can be concluded that the re-structuration of food consumption patterns in Hungary is an important and urgent task, which serves both the public health and ecologic goals. These efforts should be based on a complex evaluation of the problem. This study was one initial step to analyse SN focused on Hungary and further studies are definitely needed.

This research elaborated in greater depth how the connectivity of WEF flows occurs and how their related governance networks reconfigure. This research argued that resource flows contain a social and a material dimension that interplay with one another in giving shape to resource provisioning systems and in connecting WEF. This research work contributed to the theorising of the urban nexus. It shed light on the socio-material interface of flows in shaping connections between WEF, and the actors facilitating these connections. Its main argument is that in the quest for understanding the WEF urban nexus, cities are crucial spaces in which environmental flows get configured and linked through governance networks. Some of the key actors to look at when identifying nexuses are switchers and programmers. These are actors that link and configure the socio-material flows of WEF facilitating the emergence of nexus governance networks. These actors play an important role on how nexus governance networks emerge, and how they connect and (re)configure WEF flows. This research focused on the interaction of structures, functions, and power dynamics of networks (re)connecting and (re)configuring WEF in higher or lesser nexus outcomes. This thesis proposed a set of concepts to analyse the nexus as exemplified through examples from geothermal energy in Reykjavik, a food centre showcase in Bologna, proximity food in Barcelona, the cases of the last mile of food and the car-regulated last time in Amsterdam (the experimental city). In the in-depth case study of Barcelona, this thesis argued that the sustainability of proximity food is not just determined by distance (between places of production and access) but by the specific ways in which food flows relate to connections with energy-and-water flows. We conclude that in Barcelona, proximity is developed as a concept to improve and gain on food sustainability and it has been employed as a crucial element in the re-coding of the urban food network and its food flows. However, such code and coding still deserve further developments in closing physical and social distances, not only within the food network (through its processes) but between the WEF dimensions at and through every process of food provisioning in Barcelona. In the in-depth case study of the car-regulated city of Amsterdam, this thesis unpacked the content and meaning of what occurs in distributing food in the proximity. The authors study the case of emergent e-transport alternatives distributing food in the last mile (following food flows on board of electric boats, electric vehicles, and electric bikes). The authors argued that a more sustainable last mile of food requires more than a shift toward greener modes of transport. It is also about the wider supporting urban infrastructure, including fuel shifts, alternative infrastructure provisioning (e.g. the use of canals as opposed to roads), and the socio-political infrastructure supporting or limiting the sustainable urban food transition (e.g. who supports or obstructs the transition). One of the final conclusions of this thesis suggests that governing the nexus requires a nexus interface which is mainly developed by switchers & programmers with the help of incumbent actors. The thesis concluded on two tools that switchers, programmers, and incumbents used for steering nexus projects in cities. 1) Food proximity: learning from food short supply chains and practice, and 2) New social relations organising water, energy, and food: the open-code experimental city. between urban versus global governance, for proximity or for an experimental-city policy. After critically reflecting on the pros and cons of such tools, this research suggests that researching the urban requires to also study the continuum of urban flows on the move (socio-material), across urban and global scales, through resource networks. A final thought on actors making the nexus of governance networks is that new social relations as shown in cities do not always come along straightforwardly. WEF nexus thinking needs to be assisted by guiding principles, concepts, methodologies, and tools (as proximity and experimentation, but also many other ones) that can provide an initial direction towards pathways of further connectivity. In either way, from a closed-code fashion or from a more open-source code one.

The efficacy of electrolyzed water (EW) to inactivate Listeria monocytogenes on stainless steel surfaces was evaluated and modelled in the present study. L. monocytogenes was inoculated on stainless steel coupons and subsequently subjected to Neutral EW (NEW, pH = 7.0) and Slightly Acid EW (SAEW, pH = 5.0) with different Available Chlorine Concentration (ACC, 50–200 mg/L) for different exposure times (0–6 min). The number of viable cells on coupons decreased as the exposure time increased at all ACC concentrations. Treatments with SAEW resulted in higher reductions of L. monocytogenes, i.e., 2.30 ± 0.16 to 5.64 ± 0.11 log cfu/cm2, in comparison with NEW treatments (1.55 ± 0.11 to 5.22 ± 0.12 log cfu/cm2), probably due to the synergistic bactericidal effect between the acidic pH, higher oxidation-reduction potential and the effective form of chlorine, reported in previous studies. Since SAEW was the most effective against L. monocytogenes, two approaches were tested to model the survival data: the one- and two-step modelling procedures. The Weibull model was suitable to describe the survival data and both approaches produced suitable survival models (adj-R2>0.92 and MSE<0.2). EW is effective in reducing bacterial contamination on food-contact surfaces and the survival data and models derived from this study are relevant to optimize its use as an environment-friendly sanitizer in the food industry.

Based on the GRAFS method of biogeochemical accounting for nitrogen (N), phosphorus (P) and carbon (C) fluxes through crop, grassland, livestock and human consumption, a full description of the structure and main functioning features of the French agro-food system was obtained from 1850 to the present at the scale of 33 agricultural regions. For the period since 1970, this description was compared with the results of an agronomic reconstitution of the cropping systems of the Seine watershed based on agricultural census and detailed enquiries about farming practices at the scale of small agricultural regions (the ARSeine database), which were then used as input to an agronomical model (STICS) calculating yields, and the dynamics of N and C. STICS was then coupled with a hydrogeological model (MODCOU), so that the entire modelling chain can thus highlight the high temporal inertia of both soil organic matter pool and aquifers. GRAFS and ARSeine revealed that the agriculture of the North of France is currently characterised by a high degree of territorial openness, specialisation and disconnection between crop and livestock farming, food consumption and production. This situation is the result of a historical trajectory starting in the middle of the nineteenth century, when agricultural systems based on mixed crop and livestock farming with a high level of autonomy were dominant. The major transition occurred only after World War II and the implementation of the Common Agricultural Policy and led, within only a few decades, to a situation where industrial fertilisers largely replaced manure and where livestock farming activities were concentrated either in the Eastern margins of the watershed in residual mixed farming areas or in specialised animal production zones of the Great West. A second turning point occurred around the 1990s when regulatory measures were taken to partly correct the environmental damage caused by the preceding regime, yet without in-depth change of its logic of specialisation and intensification. Agricultural soil biogeochemistry (C sequestration, nitrate losses, P accumulation, etc.) responds, with a long delay, to these long-term structural changes. The same is true for the hydrosystem and most of its different compartments (vadose zone, aquifers, riparian zones), so that the relationship between the diffuse sources of nutrients (or pesticides) and the agricultural practices is not immediate and is strongly influenced by legacies from the past structure and practices of the agricultural system. This has strong implications regarding the possible futures of the Seine basin agriculture.

Food waste is considered a serious global societal problem. How to degrade of food waste in a green and effective way has been to a hot topic. In this work, a method with hot water extraction pretreatment of food waste was investigated and optimized. Under the optimal conditions, more than half of the solid food waste could be transferred to soluble sugars. Meanwhile, in order to improve the tolerance of Rhizopus arrhizus on the food waste hydrolysate, UV combined with chemical mutagenesis were carried out, and a mutant of Rhizopus RH-7-13-807 was obtained. With the mutant strain, the yield of fumaric acid fermented from food waste increased to 1.8 times compared with the original strain, and 23.94 g/L fumaric acid was obtained from the fermentation. Besides, the COD of food waste was evaluated for the degradation of food waste by the Rhizopus RH-7-13-807. The process would decrease the quantity of food waste to be disposed of, and benefit the environment.

A nexus approach can support the transition to sustainability by addressing trade-offs and pursuing synergies to improve water, energy, and food security. In this paper, a participatory system dynamics model was developed to identify and assess the key interlinkages between water, food, and energy in Andalusia (Spain). A panel of relevant stakeholders contributed to all stages of the model’s development. Further, by calibrating the model to CAPRI-Water projections until 2050, the evolution of the system under a plausible climate scenario, as well as effects of water prices changes, was evaluated. The results revealed a close link between water cost, irrigation water use, energy consumption, and the economic development of agriculture in the region. Large variability was observed in the effects of water pricing policies across crops. This paper concludes that a participatory system dynamics model can help in understanding the nexus synergies and can support the design of more coherent sustainability strategies in the region.