THE RISE OF URBAN FARMS

Food supplies benefit from urban agriculture – Akila Wijerathna explains

Feeding a projected global population of nine billion people by the middle of the 21st century is one of the most pressing challenges humanity faces – especially while aiming to reduce its agricultural footprint.

Traditional methods to increase crop production often involve either land clearing or the more intensive use of existing croplands. However, both approaches are linked to major drawbacks such as biodiversity loss and increased greenhouse gas emissions.

In contrast, urban agriculture (UA) – which involves growing crops within city limits for human consumption – offers a promising alternative.

By utilising already cleared urban land, UA can increase global food supplies and potentially enable ‘land sparing’ in rural areas, preserving natural ecosystems and mitigating some negative environmental impacts associated with traditional agricultural expansion.

The ability of urban agriculture to satisfy a portion of global food demand shows promise with studies demonstrating that it can often produce higher yields of fruits and vegetables compared to rural farms.

Estimates of UA’s contribution to global food supply vary widely. Some suggest it accounts for between 15 and 20 percent of the world’s food production while others believe this estimate to be an overestimation.

This disparity underscores the need for more accurate and comprehensive research to assess urban agriculture’s true impact, and optimise its role in the global food system.

In developing countries, urban agriculture has shown considerable potential to improve food security and dietary diversity. Conversely, in developed nations, research has largely focussed on the social benefits of UA, highlighting a range of positive social outcomes.

It has also proven effective in producing high value perishable crops such as vegetables near their consumption sites. This proximity ensures fresh produce and is particularly beneficial in low income ‘food desert’ areas where access to fresh healthy food is constrained by geographic and economic barriers.

So while the productive capacity of urban agriculture is more emphasised in developing countries, its social and nutritional advantages are significant in developed regions as well.

To develop a robust UA industry, integrated science, technology and supply chain innovations are essential.

Historically, agriculture was excluded from urban areas due to the high value of urban land. However, recent advancements in intensive protected cropping, hydroponic production and plant factory with artificial lighting (PFAL) technologies are making it increasingly feasible to reintroduce agriculture into urban settings.

Key areas requiring further technological development include digital monitoring and feedback control mechanisms, breeding for intensive controlled environment production systems, and improving efficiencies in nutrient, light, CO2 and water use, and nutrient recycling, along with optimising models for efficient urban agriculture production and distribution.

UA is integral to food production in many parts of the globe with an estimated 800 million people contributing as much as 20 percent of the world’s food requirements.

Despite its widespread practice, there is no single formal definition for urban agriculture. It varies based on local policy, state or community specifics and is often tailored to fit in with funding or programming needs.

For instance, the US Environmental Protection Agency (EPA) says that urban agriculture includes backyards, rooftops, balcony and community gardening, in vacant lots and parks, roadside urban fringe agriculture and livestock grazing in open spaces.

The US Department of Agriculture (USDA) expands this definition to include the cultivation, processing and distribution of agricultural products in urban and suburban areas – i.e. in community gardens, on rooftop farms, at hydroponic ‘aeroponic’ and ‘aquaponic’ facilities, and vertical production.

UA encompasses various production methods and delivers an array of produce. Traditional techniques include production in ground and raised bed gardening, as well as controlled environment methods such as hoop houses, high tunnels and greenhouses.

The type of food produced through urban agriculture is diverse but generally focusses on speciality crops such as fresh fruits and vegetables, leafy greens, micro-greens, mushrooms and flowers.

Urban farms also produce value added and aquaculture products, poultry and compost. Unlike rural agriculture, urban farming rarely places an emphasis on high volume commodity crops that include corn, soy and so on.

And urban agriculture provides healthier diets, reduces food miles and waste, creates local employment and utilises underused land.

As urbanisation increases, integrating innovative and sustainable urban farming practices is crucial for improving food security and resilience in urban environments.