The Role of Urban Agriculture as a Nature-Based Solution: A Review for Developing a Systemic Assessment Framework

Abstract

Urbanization and achieving sustainable agriculture are both major societal challenges. By reducing food miles and connecting people with nature, food cultivation in cities has several major advantages. However, due to further urban development (peri-) urban agriculture (UPA) is under threat. To strengthen UPA, we argue for considering UPA as a nature-based solution (NbS) supporting systemic approaches for societal challenges. However, academic knowledge on UPA's contribution to various societal challenges of urbanization is still fragmented. This study addresses the gap by conducting a systemic literature review, incorporating 166 academic articles focusing on the global north. The results of the review show that UPA contributes to ten key societal challenges of urbanization: climate change, food security, biodiversity and ecosystem services, agricultural intensification, resource efficiency, urban renewal and regeneration, land management, public health, social cohesion, and economic growth. The value of UPA is its multifunctionality in providing social, economic and environmental co-benefits and ecosystem services. When implementing UPA, social, institutional, economic, technical, geographical, and ecological drivers and constraints need to be considered. To upscale UPA successfully, the study develops an integrative assessment framework for evaluating the implementation and impact efficiency of UPA. This framework should be tested based on the example of edible cities.

Excess phosphorus from compost applications in urban gardens creates potential pollution hotspots

“…Desired outcomes for UA, in the context of sustainability, include increasing local food production while recycling organic waste through composting (Metson and Bennett 2015b). UA has previously been characterized as resource-efficient based on its use of vacant spaces, the potential use of stormwater for irrigation, and the reduction of food miles (Artmann and Sartison 2018), although UA is inefficient in terms of human labor requirements (McDougall et al 2019). Our results show that urban gardens in one major US metropolitan area are characterized by high nutrient inputs and inefficient conversion of these nutrients into crops.…”

“…Urban agriculture can take a variety of different forms, but most outdoor urban agriculture (including backyard and community gardens, as well as commercial urban farms) typically relies heavily on compost-derived nutrients (Metson and Bennett 2015a). If UA can increase urban nutrient recycling, that would add to a number of other environmental, social, and cultural benefits that have been described (Recknagel et al 2016, Artmann and Sartison 2018, Clinton et al 2018.…”

Key Enablers of and Barriers to the Uptake and Implementation of Nature-Based Solutions in Urban Settings: A Review

“…Davies and Lafortezza [45] mentioned the focus of NBS on applicability of solutions as an important added value. Overall, cross-sectoral multifunctionality is the main factor that makes NBS interesting for stakeholders and a strong investment option for sustainable urban development [8,9,13,15,27,36].…”

“…In particular, NBS have been noted to be highly effective in enhancing ecosystem stewardship and sense of place among affected populations, especially vulnerable people and low-income groups who are typically under-represented [26]. This benefit is especially acknowledged in relation to urban gardens and urban agricultural areas, where citizens directly participate in the management, maintenance and monitoring of NBS [15,35,36,49]. The role of NBS in providing health and well-being benefits such as improved mental health, e.g., [51], and encouraging healthy and dynamic life styles, e.g., [39] were also emphasized in the reviewed publications.…”

“…While the EC [7] maintains a particular focus on the potential of NBS to create job opportunities, this benefit is hardly or not considered in any of the reviewed studies. The economic benefits of NBS are typically limited to the cost effectiveness of specific solutions, e.g., [29] and the job creation potential of NBS is only explicitly articulated in the context of urban agriculture [15,36]. Notably, the results of this analysis might possibly have been more in favor of biophysical challenge areas, if we would have included studies drawing on a more technical perspective.…”