Trends and gaps in scholarly literature on urban and peri-urban agriculture

Abstract

In recent years urban and peri-urban agriculture (UPA) has gained increasing attention, while a comprehensive synthesis and identification of research gaps is lacking. The present review indicates that with a share of 27% of scholarly publications sub-Saharan Africa is the geographical region most often reported in scientific literature. Middle East and North Africa (MENA, 1.9%) and Oceania (2.8%) in contrast appeared underrepresented. Megacities (> 5 million inhabitants) received less scientific attention than smaller agglomerations. 3.6% of UPA publications addressed heavy metals, of which 82% detected a contamination in plants, soil or irrigation water above recommended thresholds, but the thereby bioavailability of heavy metals remains unclear. Organic pollutants in contrast seem to be understudied. 1.7% of the studies focused on microbial contamination in UPA and 9.7% addressed socio-economic aspects of urban agriculture. The latter are very context specific and span from supplementation of food in poor households to market-oriented production. Only 2% of studies explicitly dealt with animal husbandry in UPA. This topic should receive more scientific attention, since the integration of urban animal husbandry with cropping systems has large potential for recycling of nutrients. Similarly, only 2.4% of studies examined urban foodsheds and food supply, despite the challenge of ongoing urbanization, which requires increasing source areas for feeding cities. Maintaining ecosystems services in an urban environment that is highly competitive for scarce resources such as space, water, labour and capital requires an efficient resource management at different spatial scales. This calls for interdisciplinary research approaches in a social-ecological systems framework.