Elvira Molin

Public procurement has been recognized as a tool to promote more sustainable production and consumption practices. As such, an increasing body of literature has become available in recent years focusing on the sustainable public procurement of food. This article reviews the literature on the sustainable public procurement of food with the aim to analyze how sustainability is framed. This is done by analyzing what aspects of sustainability are emphasized and what practices are identified as sustainable. A systematic literature review was conducted between the years 2000 and 2020, identifying 103 articles. Results from the literature review indicate that the focus has primarily been on studies to evaluate and explore policy and good practices for procuring sustainable foods. A dominant focus on specific foods types and origins, e.g., those locally sourced and organic foods, is highlighted by a large share of the literature to address all three sustainability pillars. We observed that most articles focus on all three pillars of sustainability (environmental, social, and economic), addressing different aspects and types of foods, although the focus varied depending upon geographic location. Despite many studies identifying opportunities and potential, few articles assess the sustainability or outcomes of procurement processes through quantitative or qualitative methods or how actors in the procurement process can improve procurement toward more sustainable foods. This indicates a need for further case studies and guidelines to measure the development, progress, and performance of public food procurement.

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.

With an expanding population and changing dynamics in global food markets, it is important to find solutions for more resilient food production methods closer to urban environments. Recently, vertical farming systems have emerged as a potential solution for urban farming. However, although there is an increasing body of literature reviewing the potential of urban and vertical farming systems, only a limited number of studies have reviewed the sustainability of these systems. The aim of this article was to understand the environmental impacts of vertical hydroponic farming in urban environments applied to a case study vertical hydroponic farm in Stockholm, Sweden. This was carried out by evaluating environmental performance using a life cycle perspective to assess the environmental impacts and comparing to potential scenarios for improvement options. The results suggest that important aspects for the vertical hydroponic system include the growing medium, pots, electricity demand, the transportation of raw materials and product deliveries. By replacing plastic pots with paper pots, large reductions in GHG emissions, acidification impacts, and abiotic resource depletion are possible. Replacing conventional gardening soil as the growing medium with coir also leads to large environmental impact reductions. However, in order to further reduce the impacts from the system, more resource-efficient steps will be needed to improve impacts from electricity demand, and there is potential to develop more symbiotic exchanges to employ urban wastes and by-products.