The presence of reactive species of nitrogen (N) in the biosphere might cause environmental impacts at local, regional and global scales. Nowadays the N flows generated by human activities greatly exceed natural processes, thus a necessity exists of identifying and quantifying the current state of environmental N loads. The aim of this work is to quantify the amount of reactive N used in the Spanish agri-food sector, assessing the related potential environmental impacts and potential uses of resources. Data from a previously calculated N flow analysis in the Spanish agricultural and food production system for the 1996-2000 time period were used. Total anthropogenic N inputs to the systems were calculated. Input and output flows were considered in each economic compartment in order to calculate use efficiency (ratio of useful outputs to total inputs), eco-efficiency (ratio of useful outputs to outputs to the environment) and recycling rate (ratio of flow recycled to an earlier life-cycle compartment divided by total outputs). Environmental impacts were assessed by quantifying the N balance between the economic and the environmental subsystems: water, atmosphere, ecosystems soils and other soils. In this case agricultural soils were also considered an environmental compartment, since they are an important intermediate path to the environment. The impact on resources was evaluated considering the net N imports into the system and legume fixing crops, pastures and forages versus feed and fertilizers within the system. Anthropogenic N inputs are relatively high in Spain, which is a net importer of nitrogen, mainly in fertilizers and food and feed commodities. Environmental compartments receive relative high amounts of reactive nitrogen, especially soils. Furthermore, there was a relative low use of domestic resources, with a low proportion of N recycled within the system.

Abstract: To enhance water, energy, and food security and promote ecosystems conservation, it is necessary to design policies or solutions capable of addressing cross-sectoral challenges. In this paper, GoNEXUS SEF, an evaluation framework for co-designing and evaluating nexus solutions, is presented. This framework provides guidelines for conducting a nexus-coherence assessment to improve the governance of the water-energy-food-ecosystems nexus. The assessment involves a participatory process that integrates qualitative and quantitative methodologies through systemic approaches. The crucial aspects necessary in the development of methodologies that address the nexus have been identified and considered. The framework was applied to a practical case study, an increase in the irrigation water price in Andalusia—Spain for the horizon of 2030. Case study results revealed that the measure can generate synergies since it favours water savings, irrigation water efficiency and ecosystems conservation. However, trade-offs are observed, mainly undermining the economic development of agriculture in the region. GoNEXUS SEF has proven capable of evaluating nexus solutions by measuring cross-sectoral synergies and trade-offs. It highlights hidden properties and identifies leverage points and key aspects of a complex cross-sectoral system to apply nexus solutions more effectively to promote sustainable development. In addition, the framework can be adapted to fit different case studies, considering their own challenges and their spatial and temporal scales, which gives it a competitive advantage over other methodologies focused on analysing the nexus. Graphical abstarct: [Figure not available: see fulltext.].

The promotion of responsible consumption is a key strategy to achieve environmental benefits, sustainable food security, and enhance public health. Countries like Spain are making efforts to reverse growing obesity and promote healthy diets, such as the recommended and traditional Mediterranean, recognized as a key strategy to improve the population's health with locally grown, traditional, and seasonal products like fruits, vegetables, olive oil, and fish. With a view to connecting water, agriculture, food security, nutrition and health, this research aims to investigate and compare the nutritional and water implications of the current food consumption of Spanish households with the recommended Mediterranean diet. Besides, we calculate their nutritional composition, compare their water footprints, and develop a new methodological approach to assess nutritional water productivity (i.e. the nutritional value per unit of embedded water). Results show that the current Spanish diet is shifting away from the recommended Mediterranean towards an alternative one containing three times more meat, dairy and sugar products, and a third fewer fruits, vegetables, and cereals. The Mediterranean diet is also less caloric, as it contains smaller amounts of proteins and fats and is richer in fiber and micronutrients. Due to the high embedded water content in animal products, a shift towards a Mediterranean diet would reduce the consumptive WF about 750 1/capita day. Additionally, the Mediterranean diet has better water-nutritional efficiency than the current one: it provides more energy, fiber, and nutrients per liter of consumptive water. The study confirms the Mediterranean diet is a healthier and more sustainable diet with strong cultural heritage.

El objetivo general del presente trabajo es realizar diferentes tratamientos de activación de residuos agroalimentarios para utilizar en la eliminación de nitratos en aguas. Como objetivos más específicos se han fijado los siguientes: Acondicionar la residuos agroalimentarios a emplear Realizar diferentes tratamientos de activación Caracterizar la biomasa antes y después de la activación Estudiar la capacidad de retención de la biomasa modificada Redactar el TFM Resumen de la Oferta: Se pretende valorizar diferentes residuos procedentes de la industria agroalimentaria, para emplear como adsorbentes de nitratos presentes en aguas. Para ello, y con objeto de mejorar el rendimiento de eliminación se procederá a realizar diferentes tratamientos de activación. Posteriormente se caracterizarán las biomasas sin modificar y modificadas, así como se procederá a evaluar su capacidad de retención. | Escuela Técnica Superior de Ingeniería Industrial | Universidad Politécnica de Cartagena