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The greenhouse sector has seen many advances to improve its resource demands, though little is known of the environmental impacts. This study aims to assess the environmental performance of a horticultural greenhouse in Sweden producing herbs. Life cycle assessment is employed to analyze different scenarios. These include previous measures, such as switching to organic fertilizers, a pellet burner, and reducing the packaging weight. Future scenarios are assessed, including increasing biofueled logistics, switching to LEDs, densifying production, and including recyclable packaging. The results suggest that GHG emissions were reduced by 32% per kg edible portion through past scenarios in current scenario. Additionally, densifying production and switching to LED lighting can lead to an additional 14% and 10% reduction in GHG emissions compared to the current system respectively, while also reducing other environmental impact categories. These results provide insights into the implications of environmental and resource improvement measures taken at greenhouses., QC 20230707

Alternative food production technologies are being developed to meet the global increase in population and demand for a more sustainable food supply. Aquaponics, a combined method of vegetable and fish production, is an emerging technology that is widely regarded as sustainable. Yet, there has been limited research on its environmental performance, especially at a commercial scale. In this study, life cycle analysis (LCA) was used to assess the environmental impacts of food produced by an urban commercial aquaponic system located next to a retail store in a cold-weather region (Östersund, Sweden). The functional unit (FU) used is 1 kg of fresh produce, which includes cucumber (Cucumis sativus), tomatoes (Solanum Lycopersicum), and Atlantic salmon (Salmo salar). The system boundary is set from cradle to farm or retailer's gate due to the proximity of the aquaponic system to the retail store. Results were reported employing eight environmental impact categories, including global warming potential (GWP), marine eutrophication (MEU), and cumulative energy demand (CED). According to contribution analysis, the main hotspots of the system are electricity, CO2 enrichment, and heating. Potential areas to mitigate the impact of these parameters were highlighted in this study, including the establishment of symbiotic links to utilize urban waste and by-products. The impact per vegetable or fish produced was partitioned using energy and economic allocation and compared to other common cultivation methods. The yearly harvest from the aquaponic system was also compared to importing these food items from other European countries which showed lower annual greenhouse gas (GHG) emissions for the aquaponic system., QC 20230711

Vertical farming has emerged in urban areas as an approach to provide more resilient food production. However, a substantial share of the material requirements come from outside their urban environments. With urban environments producing a large share of residual and waste streams, extensive potential exists to employ these material and energy streams as inputs in urban farming systems to promote more circular economy approaches. The aim of this article is to assess the environmental performance of employing residual material flows for vertical hydroponic farming in urban environments in order to support more circular, resilient, and sustainable urban food supply. Life cycle assessment (LCA) is used to assess replacing conventional growing media and fertilizers with urban residual streams. Paper, compost, and brewers' spent grains were assessed for replacements to conventional gardening soil employed in the studied system. Biogas digestate was also assessed as a replacement for conventional fertilizers used in the recirculating water bath. The results suggest that large environmental performance benefits are illustrated when conventional growing media is replaced. Although not as significant, employing fertilizers from residual urban streams also leads to large potential benefits, suggesting the two residual streams have the potential for more circular hydroponic systems., QC 20200409