Healthy soils for more resilient and greener cities

Our cities are expanding fast; already home to around 55 percent of the world's population, a figure expected to rise to 68 percent by 2050. As urban areas grow, so does the pressure to provide fresh, safe, nutritious food and to build spaces that can withstand a changing climate. The key to meeting these challenges lies right beneath our feet—soils, the often-overlooked foundation on which they are built.

Soils in cities do far more than simply support buildings, roads and other infrastructure; they sustain resilient and green cities. Understanding this connection can enable us to design and build better homes and communities in the future. It also reinforces the One Health approach, which recognises that healthy soils support the health of people, animals, plants and the environment.

On this year’s World Soil Day, the Food and Agriculture Organization of the United Nations (FAO) reminds us that healthy soils are the foundation of healthy cities, underpinning agricultural development, food security, ecosystem functions, biodiversity and  resilience to climate change.

Here are four important ways soils and cities are connected:

1. Soils provide food for urban and peri-urban population

Over 80 percent of the food consumed in cities comes from family farmers who rely on healthy soils in rural areas. Investing in more sustainable agricultural practices and soil health in rural areas helps meet the rising food needs of expanding urban populations, while also protecting farmers’ livelihoods and strengthening global food security.

Healthy urban soils currently supply about 10 percent of global vegetables, legumes, and tubers for cities. They can help feed urban and peri-urban populations by ensuring that safe, fresh food grown in plots, gardens, or even on rooftop farms, remains available and accessible to urban markets. Urban agriculture remains an important part of urban socio-economic systems and provides new job opportunities for urban residents.

Through integrated land use planning, compact urban growth, and agrifood system integration, we can safeguard soils, secure food and build more sustainable cities. The City Region Food System (CRFS) planning offers one approach, encouraging farming in and around cities to boost food security and local economies. 

2. Soils can reduce pollution, extreme weather events and temperatures in cities

Cities are centres of traffic and sources of industrial pollution, waste and wastewater. As a result, urban soils can become easily polluted, posing serious health risks for residents. Actions are needed to identify, manage and restore such polluted urban soils. Integrating green spaces, tree pits and green corridors can help filter pollutants.

Healthy soils in turn enable greater green coverage, which absorbs less heat than concrete and asphalt, lowers surface temperatures, absorbs rainwater and reduces landslides and floods. As we build more roads and buildings, more urban soils are sealed. Preventing and reversing soil sealing through city greening, on the other hand, can keep cities cool and mitigate extreme weather by sequestering carbon, retaining water and fostering biodiversity.

3. Soils help boost human health and well-being

Healthy soils are the foundation for urban and peri-urban forests, parks, gardens and urban trees.

Living in cities surrounded by trees and parks provides recreation, supports well-being and human health. Green spaces are proven to improve mental health by reducing stress, anxiety and depression, and the simple act of spending time around trees can strengthen positive emotions. And because parks and gardens also encourage physical activity for all, when soils thrive and cities green, communities thrive too.

4. Soil health is a good driver for better city waste management

Cities generate about 70 percent of global waste. Improving how cities manage waste can directly benefit urban soils. When organic materials are safely separated and processed into compost, biochar, or biowaste through black soldier fly, and then applied to perennials or urban farms, they return nutrients back to the soils and support urban farming and healthier urban soils.

FAO’s Green Cities Initiative (GCI), which aims to build vibrant, inclusive and resilient places that are good for people and nature. Redesigning cities to be truly sustainable requires reimagining how we manage our spaces, produce our food and use our resources. This transformation can start with one fundamental element: healthy soils.