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The role of environmental consequences derived from cereal production in agricultural systems is widely recognised. Life Cycle Assessment (LCA) has been considered as a useful tool to support environmental decision-making in agricultural systems. In this study, the quantification and identification of the environmental impacts derived from two different double cropping systems comprising winter and summer crops for silage production (forage sorghum, barley and oat) was performed following an attributional LCA perspective in accordance with ISO 14040 standards. Primary data of cereal production for dairy cattle feeding were obtained from a representative year. Only secondary data were used for background processes. Four different functional units were considered to report the environmental profiles: 1 t dry matter silage (base case), 1 ha, 1 t crude protein and 1 MJ metabolisable energy. According to the results, the combination of sorghum with barley presented better environmental results than sorghum with oat when the impacts were reported for mass and energy based functional units, which is attributed to the biomass yield (23% higher) achieved under similar agricultural practices. When the functional unit of 1 ha was taken, the scenario of sorghum and oat was more beneficial due to lower requirements of diesel and herbicides for the agricultural activities per cultivation area. Regardless the functional unit considered, both field preparation and biomass harvesting were the agricultural stages which reported the largest contributions to the environmental impacts (∼99%) due to on-field emissions associated to manure application, diesel use in agricultural machinery and seed production. If the crops are separately assessed, sorghum cultivation system would be the best option due to the highest biomass yield, followed by barley and oat considering 1 kg dry matter silage as functional unit. However, when 1 ha was considered to report the results, the barley system was the worst alternative due to the highest seed ratio and diesel requirements (high input-output system). Environmental results must be interpreted within limitation of assumptions accepted by LCA community. Variations on climate and soil parameters as well as nutrients uptake by crops should be analysed and required in further research in order to reduce uncertainties.

Alfalfa is the major forage crop produced in temperate regions worlwide. Although this crop is currently used mainly for producing high-value livestock feed, its application for bioenergy production is a recent focus of interest. Even though it is not mandatory, alfalfa is normally dried in order to improve the quality of the final product. In this study, Life Cycle Assessment (LCA) was used to quantify the environmental impacts linked to alfalfa production in the major cultivation zone in Spain (Ebro Valley), including field activities, dehydration and transport to farms for livestock feeding. In addition, the identification of the most relevant processes contributing to the environmental impact and the potential improvements actions were also defined as objectives. Inventory data were obtained mainly from interviews with farmers complemented with published literature and comments from experts. LCA results were obtained for global warming, acidification, eutrophication, photochemical oxidant formation, land use, non-renewable cumulative energy demand and human, terrestrial and aquatic ecotoxicities. Within the life cycle of alfalfa, the dehydration process, production of phosphate fertilizer, application of nitrogen fertilizers and pesticides, water consumption and final transport to the consumer (by road and ship) were identified as hot spots. Based on these, some improvement measures were proposed and evaluated: (i) reduction of the moisture content of alfalfa and the use of a higher percentage of biomass for combustion in the dehydration process, (ii) no application of nitrogen fertilizer in maintenance years and (iii) use of more efficient trucks for transport. Their implementation would produce significant reduction of eutrophication, global warming, acidification, non-renewable cumulative energy demand and, to a lesser extent, photochemical oxidation formation and human toxicity impacts.

The environmental assessment of the processing and consumption of mussels of the species Mytilus galloprovincialis was carried out for both fresh and canned mussels. For this purpose, the application of Life Cycle Assessment (LCA) was considered. Inventories for mussel purification in dispatch centres and mussel transformation in canning factories were performed, along with those for household consumption of fresh and canned mussels. Environmental characterization results were computed for different impact categories, including abiotic depletion, global warming, ecotoxicity, human toxicity, acidification, ozone layer depletion, photochemical oxidant formation and eutrophication. As a whole, the environmental hot spots for fresh mussel processing included electricity and chlorine gas production, as well as water discharge in dispatch centres. Similarly, the environmental hot spots for canned mussel processing comprised electricity production, can production and transport, oil production, and fuel oil production. Finally, the implementation of the previous mussel culture stage into the LCA of mussel processing and consumption showed the relevant role of the mussel culture system when assessing the potential environmental impacts of mussel-based products.

Recently, Iribarren et al. (in press) reported the results of a Life Cycle Assessment (LCA) for mussel cultivation in rafts in the northwest coast of Spain. A Life Cycle Inventory (LCI) and its corresponding Life Cycle Impact Assessment (LCIA) were carried out from the definition of a representative mussel culture vessel and an average raft. Since data were available on a whole sample of 83 mussel cultivation rafts, an LCI and an LCIA have been developed for each one separately and an efficiency analysis has been performed to identify those rafts that have the best practices and therefore can serve as benchmarks for the rest. A Slacks Based Measure (SBM) of environmental impact efficiency has been computed using Data Envelopment Analysis (DEA), taking into account the different inputs (as recorded in the LCI) as well as the characterization values for 10 environmental impact categories. An environmental impact efficiency score and reduction targets for both input consumption levels and environmental impacts have been computed. The estimated environmental impacts reduction potential for the whole sample ranges from 11% for terrestrial ecotoxicity to 67% for ozone layer depletion. This environmental performance assessment method is rather general and can be used in other LCA studies in order to identify operational inefficiencies and to reduce environmental impacts.

In Galicia (NW Spain), the mussel sector is an economic and social cornerstone, with great relevance at both regional and international scales. The environmental impact of this sector has been recently discussed from a Life Cycle Assessment (LCA) perspective. In previous studies, it was concluded that the management of mussel shells and mussel organic by-products needed to be implemented into future life cycle assessments. In this article, LCA methodology was used in order to assess the environmental performance of two valorization alternatives for mussel by-products: mussel shell valorization to produce calcium carbonate, and mussel organic remains valorization to produce pâte. From the environmental characterization for mussel shell valorization, propane and electricity production, sludge and ash management, haulage and atmospheric releases were identified as the hot-spots on which improvement potentials should be focused. Furthermore, the environmental profile for mussel shell valorization was compared to those for incineration and landfilling as alternative management options. The environmental characterization of pâte production from mussel organic by-product led to the recommendation of acting on the formulation of mussel pâte, the thermal energy demand and the product transport. Additionally, this valorization alternative was compared to another common scenario which considered the use of mussel organic by-product to manufacture fish meal. Finally, the valorization of mussel shells and organic by-products was implemented into the assessment of the Galician mussel sector. Thus, mussel by-product management was found to contribute to the potential environmental impacts to a lesser extent than mussel culture, purification and canning transformation.

At the present time, there is a remarkable increasing interest for using non-woody fibres as raw materials for pulp mills. The present study aims to identify and quantify the environmental impacts associated with the production of hemp and flax fibres for speciality paper pulp by using the Life Cycle Assessment (from now, LCA) methodology. One ton of fibre entering the pulp mill was used as functional unit in both systems. Inventory data for the foreground system (agricultural inputs and outputs) were obtained directly from growers (Spanish plantations and expert advisors) and combined, when necessary, with bibliographic sources. Data for the background system such as production of chemicals and pesticides, machinery or electricity were taken from the Ecoinvent database. The CML baseline 2000 methodology was selected to quantify the potential environmental impact associated to the crops. Specifically global warming (GWP), acidification (AP), eutrophication (EP) and photochemical oxidant formation (POP) were evaluated. In addition, two flow indicators were considered: energy (EU) and pesticide use (PU). Production of hemp fibre reported higher values for all the impact categories analyzed. On the contrary, flow indicators were more intensive in the flax scenario due to irrigation and pesticide consumption. LCA tool aided to identify the hot spots, so that a proposal for upgrading alternatives to reduce environmental impacts could be made. Production and use of fertilizers as well as the stage of scutching were identified as the hot spots in both crops; in addition, harvesting has also significant contribution in hemp production and irrigation regarding the flax scenario. Future work will be focused on the study of non-wood fibre processing in order to get a complete picture of the non-wood pulp life cycle.

Life cycle assessment (LCA) is an environmental tool which allows the calculation of all the environmental loads related to a process/product/service. In the present work, LCA was applied to analyze the environmental impact of different technologies for wastewater treatment in small populations. In this study, 13 wastewater treatment plants (WWTPs) of less than 20,000 population equivalent (p.e.) located in Galicia (NW Spain) were inventoried. The results of the evaluation of the environmental impact are expressed in terms of diverse impact categories. Normalization identified eutrophication, mainly as P-PO43−, N-NH4+ and organic load as chemical oxygen demand (COD) in the treated effluent, and terrestrial ecotoxicity, due to the heavy metals content in the sludge, as the most significant categories for all WWTPs. Electricity use plays an important role in five of seven impact categories and presents the highest importance in four of them. When comparing technologies, secondary treatment technologies such as biodenipho and aerobic–anoxic treatment resulted in a lesser environmental impact than extended aeration. The operation of the plants has large contribution on the impact, especially for those that make use of extended aeration.

Growing awareness of environmental problems during recent years has led to increased demand for environmental information about seafood products. In particular, this report is an attempt to evaluate the manufacturing process of canned-tuna products. Bearing in mind the lifestyles of people in the 21st century, canned products are one of the commonest ways in which seafood products are presented. Spain is the second largest exporter of processed tuna in the world, behind Thailand. The fish and shellfish canning industry is mainly grouped in Galicia where 65% of the total production takes place. To this aim, the method used to study the environmental impact of these products is Life Cycle Assessment (LCA), which follows a product through its entire life cycle. The system under study includes landing at harbour, transport to the factory, processing inside the factory, final product distribution to markets and use in households. The results show that processing accounted for the greatest percentage in all the impact categories, except human toxicity potential. Inside the factory, the production and transportation of tinplate was identified as the most significant contributor and, consequently, improvement actions were proposed and evaluated, such as an increase in the percentage of the recycled tinplate used and the substitution of tinplate by another packaging material. Both proposals would diminish the adverse environmental effects of this process; however they imply a change in the final appearance of the product to be consumed and, therefore, acceptance by consumers is a fundamental factor in their success.