Urban vegetable for food security in cities. A review

Abstract

Global food production faces great challenges in the future. With a future world population of 9.6 billion by 2050, rising urbanization, decreasing arable land, and weather extremes due to climate change, global agriculture is under pressure. While today over 50 % of the world population live in cities, by 2030, the number will rise to 70 %. In addition, global emissions have to be kept in mind. Currently, agriculture accounts for around 20-30 % of global greenhouse gas emissions. Shifting food production to locations with high demands reduces emissions and mitigates climate change. Urban horticulture increases global food production by exploiting new locations for cultivation. However, higher land prices and urban pollution constrain urban horticulture. In this paper, we review different urban cultivation systems throughout the world. Our main findings from ecological, economical, and social aspects are: (1) Urban horticulture activities are increasing globally with at least 100 million people involved worldwide. With potential yields of up to 50 kg per m 2 per year and more, vegetable production is the most significant component of urban food production which contributes to global food security. (2) Organoponic and other low-input systems will continue to play an important role for a sustainable and secure food production in the future. (3) Despite the resource efficiency of indoor farming systems, they are still very expensive. (4) Integrating urban horticulture into educational and social programs improves nutrition and food security. Overlaying these, new technologies in horticultural research need to be adopted for urban horticulture to increase future efficiency and productivity. To enhance sustainability, urban horticulture has to be integrated into the urban planning process and supported through policies. However, future food production should not be "local at any price," but rather committed to increase sustainability.

Rooftop production of leafy vegetables can be profitable and less contaminated than farm-grown vegetables

“…Studies have previously suggested that rooftop farming can be a valuable supplement to conventional farming, particularly with locally popular vegetables (e.g., Astee and Kishnani 2010;Li et al 2012;Taylor et al 2012;Whittinghill & Rowe 2012;Specht et al 2014;Orsini et al 2014;Eigenbrod & Gruda 2015;Sanyé-Mengual et al 2015a;Goldstein et al 2016). We further confirm that certain leafy vegetables can be as productive in yield and quality as those sold by local farms.…”

“…Cultivated land is decreasing with the rapid development of industrialization and urbanization, and farmland is losing fertility while increasingly being polluted, especially in the peri-urban zones that supply the readily perishable vegetables. Proposed as a means to augment conventional farming, arguments in favor of urban farming include benefits such as contributing to urban landscaping, decreasing the urban heat island effect, alleviating high transportation cost, reducing spoilage from long food distribution chains, providing food and jobs for city residents, and promoting food security and development (Mok et al 2014;Eigenbrod & Gruda 2015;Goldstein et al 2016). There are many types of urban farming, and roof farming is one type that does not directly compete for existing land use.…”

Zero-Acreage Farming in the City of Berlin: An Aggregated Stakeholder Perspective on Potential Benefits and Challenges

“…Scholars from various disciplines and throughout the world have addressed how urban production can serve as a new framework to change the common practice of food production, food processing, food transport and consumption [3,[7][8][9][10][11][12][13]. The underlying principle of the productive urban city can even contain a shift of common conceptions when it reaches a point where "rural" and "urban" categories themselves no longer clearly denote legible spatial units any longer [14] and cities are being defined as "Continuous Productive Urban Landscapes" [7].…”

Urban Foraging in Berlin: People, Plants and Practices within the Metropolitan Green Infrastructure

“…They can be divided into supporting services, e.g., [3,4], regulating services, e.g., [5,6], provisioning services [7] and cultural services, e.g., [8]. The ascendency of urban agriculture over the past 20 or so years has re-introduced cities, and the greenspaces within them, as places that can successfully provide provisioning services (sustenance) to urban residents across the globe, with variation in cultural and geographical contexts [9]. Largely overlooked, however, is another provisioning practice that takes advantage of already-existing cultivated and wild-growing vegetation in greenspaces: urban foraging [10].…”