Urban agriculture refers to the production of food including crops, livestock, horticulture, and other agricultural products in urban areas including towns and cities. In the United Kingdom, urban agriculture will include allotments, community farming, school farm projects, rooftop farming, greenhouses, and vertical farming.

Vertical farming as the name implies involves the use of buildings, where containers, crates and even purpose-built towers can be arranged vertically to grow fresh food including vegetables, herbs and fruits using hydroponic technology.

The interest in vertical farming grew following the publication in 2010 of The Vertical Farm: Feeding the World in the 21st Century a book by Dr Dickson Despommier.

Unlike traditional farming practices of growing food using the soil, hydroponic technology is used as the medium to provide essential nutrients to support plant growth and development. The two types of techniques used in hydroponics involves the need to support the roots of the plants using an inert material (rock wool or perlite) or not support the roots; in both techniques water is used to provide a nutrient solution for the growth of the plants.

In agriculture, nutrients are available from the soil for the plants to grow. These nutrients are divided into two categories: macronutrients and micronutrients. The nutrient solution used in hydroponics system will provide a balanced mix of these macronutrients & micronutrients.

Other essential considerations to support plant growth and improve crop yield include the provision of an aerating system (plant roots do not thrive in waterlogged conditions as they need access to oxygen), monitoring the pH of the water solution (pH influences the availability of the macronutrients and micronutrients) and LED light (to provide light source for photosynthesis to occur).

Advantages

1. It enables the production of fresh food particularly vegetables and herbs closer to urban centres where there is more demand.
2. Most vertical farms have established supply chain arrangements by supplying restaurants and hotels with fresh vegetables. Some restaurants have gone as far as to have versions of vertical farms within their premises – wall farms; providing an innovative way to reach more customers within the framework food sustainability.

3. It requires less space for food production compared to traditional agricultural systems.
4. It supports the possibility of growing food all year long without the attendant issues of pest, drought and faced by traditional agriculture
5. It can be set up in a wide range of buildings including abandoned or derelict buildings thereby contributing into regeneration efforts in urban communities.
6. It is possible to incorporate purpose built vertical farms in the new urban building plans and projects
7. It provides an opportunity to mitigate against the effects of climate change by reducing the carbon footprint for food to plate, more use of water conservation practices (water recycling) and sustainable use of resources including building (abandoned or derelict) and energy (renewable sources).
8. It is a versatile form of farming that can be replicated in diverse places worldwide thereby contributing to the food production to meet an increasing population demand for food. Vertical farming is used in the United States, United Kingdom, Europe, Singapore, Japan, South Korea, Australia, Kenya, and Nigeria.
9. It offers a strategy to create employment opportunities within the farming sector and associated sectors.

3. It requires less space for food production compared to traditional agricultural systems.
4. It supports the possibility of growing food all year long without the attendant issues of pest, drought and faced by traditional agriculture
5. It can be set up in a wide range of buildings including abandoned or derelict buildings thereby contributing into regeneration efforts in urban communities.
6. It is possible to incorporate purpose built vertical farms in the new urban building plans and projects
7. It provides an opportunity to mitigate against the effects of climate change by reducing the carbon footprint for food to plate, more use of water conservation practices (water recycling) and sustainable use of resources including building (abandoned or derelict) and energy (renewable sources).
8. It is a versatile form of farming that can be replicated in diverse places worldwide thereby contributing to the food production to meet an increasing population demand for food. Vertical farming is used in the United States, United Kingdom, Europe, Singapore, Japan, South Korea, Australia, Kenya, and Nigeria.
9. It offers a strategy to create employment opportunities within the farming sector and associated sectors.

Disadvantages

1. It is currently limited in the types of crops that can be grown. Vertical farming supports the growth of mainly vegetables particularly leafy ones and herbs. Opportunity exists for more research in this area to increase the choice of food products available from vertical farming.
2. There is the need for energy and climate control. The use of LED and the build-up of carbon dioxide within the vertical farm environment must be constantly monitored.

In addition to the advantages above, there is a growth in the use of vertical farming which can be attributed to changing eating habits that is embracing healthy and organic foods and the opportunity to address the issue of household food security.