Leveraging Biowaste to Revitalise Urban Agriculture

Soil degradation is one of the most pressing threats to Europe’s resilience.
Today, an estimated 70% of EU soils are unhealthy, driven by unsustainable land use management, urban sprawl, proliferation of invasive species, pollution, and climate change. Without urgent action, up to 90% of global soils could be degraded by 2050 (Rosier, Florence 2024).

In the outskirts of Barcelona, once-fertile farmland has turned hard-packed and lifeless, while cultivated land in the metropolitan region has fallen from 20% to just 8% in a single decade (Langemeyer 2024). While many cities face declining soil quality and shrinking agricultural land, others are taking a different path. In Vienna, around 15% of the city’s area is dedicated to agriculture, with a significant share managed organically—demonstrating how strong policy support can sustain productive farmland even within a dense urban setting (Vienna Tourist Board, n.d.). The city itself operates about 2,000 hectares of organic farmland, making it one of Austria’s largest organic producers (IFOAM Organics Europe 2023).

Soils are not only physical ground—they are living infrastructure.
Healthy soils support local food production, storing carbon, managing stormwater, filtering pollutants, enhancing biodiversity, and protecting public health. They are central to the functioning of entire urban and peri-urban ecosystems—linking climate regulation, nutrient cycling, vegetation health, and water quality. When soils degrade, the impacts cascade through both natural and human systems, undermining urban resilience and ecosystem stability.

Many cities and regions rely heavily on synthetic fertilisers, despite the fact that they cannot replace the functions of healthy, living soils. This method of nutrient application does not support the development of healthy soil structure or function. Moreover, the production of synthetic fertilisers contributes significantly to greenhouse gas emissions, while their overuse leads to water pollution and biodiversity loss.

Urban policy has largely overlooked the opportunity beneath our feet.
Despite producing nearly 2.8 billion tonnes of organic waste annually, cities have not prioritised systems that recover nutrients or regenerate soil health (Resilient Cities Network 2022). In addition, nutrient recovery—a process that captures and reuses valuable elements like nitrogen and phosphorus from organic waste—remains underutilized.

Source:

https://resilientcitiesnetwork.org/wp-content/uploads/2025/07/NutriSoil-Policy-Brief.pdf