How is urban agriculture practiced, institutionalized, implemented, and sustained? A literature review

Urban agriculture (UA) has emerged as a crucial strategy for ensuring sustainable food access in both developing and developed nations. However, the interplay between planning regulations and land availability significantly influences farmed land's scope and location, directly impacting UA activities' scale and intensity. The spatial mechanisms governing land use for UA stem from planning regulations, which may or may not align with food policies shaped by municipal actors-whose objectives often differ from those of civil actors. This review analyzes current urban agriculture practices in cities to explore how UA is practiced, institutionalized, implemented, and sustained, considering the influence of governance mechanisms and focusing on land-based forms of UA. By reviewing 51 peer-reviewed articles, consistent challenges impeding UA across various contexts were identified. Key factors include discord between civil and municipal actors, contextual elements affecting the enactment of supportive UA policies, and urban densification encroaching upon UA land. While these issues vary between developed and developing cities, they are primary drivers of informal or constrained UA practices and tenure insecurity. The review concludes that policies aimed at regulating UA to enhance food security should prioritize scaling up farming practices by ensuring access to larger plots with more secure tenure durations. Additionally, it emphasizes the need for flexible land-use and zoning ordinances that accommodate dual land uses, the establishment of UA protection zones to counter urban densification, and the active participation of civil actors in the process.