Title: Mapping direct N2O emissions from peri-urban agriculture: The case of the Metropolitan Area of Barcelona / Geographically explicit datasets reflecting local management of crops are needed to help improve direct nitrous oxide (N2O) emission inventories. Yet, the lack of geographically explicit datasets of relevant factors influencing the emissions make it difficult to estimate them in such way.
Title: Extended use and optimization of struvite in hydroponic cultivation systems / Hydroponic systems are an attractive form of urban agriculture due to their low weight load, inert substrate conditions, and overall better control of plant nutrition and growth. However, gaining urban food sovereignty cannot be at the cost of increasing environmental impacts.
The COVID-19 pandemic unveiled the fragility of food sovereignty in cities and confirmed the close connection urban dwellers have with food. Although the pandemic was not responsible for a systemic failure, it suggested how citizens would accept and indeed support a transition toward more localized food production systems.
Housing estates, that is, mass social housing on middle‐ and high‐rise apartment blocks, in urban areas are found all over the world with very similar constructive patterns and a multiplicity of environmental and socio‐economic problems. Boosting new urban spaces of resource production involves citizens in sites which face social and economic needs.
The Covid-19 pandemic newly brings food resilience in cities to our attention and the need to question the desired degree of food self-sufficiency through urban agriculture. We argue in this essay that this development has widely taken place due to three blind spots in urban planning.
Urban agriculture, while being a promising solution to increase food sovereignty in cities, can lead to an unprecedented discharge of nutrient and fertilizer-related emissions into the urban environment. Especially relevant are nitrogen (N) and phosphorus (P), due to their contribution to marine and freshwater eutrophication.
Optimizing urban resources through circular economy principles offers the opportunity to close loops and improve production systems, but an assessment of these systems through a combination of circularity and environmental tools is missing from the literature.