The need to optimise farming and improve yields on small plots of land is increasingly important. Due to challenges of water scarcity, limited arable land and high inputs costs, innovative solutions such as vertical farming can help to overcome these struggles.
Vertical farming is an approach whereby farmers cultivate certain crops vertically in stacked layers, in order to maximise space and increase yields. This is usually achieved by planting these crops in containers, structures, or stackable pots.
Most often, these structures incorporate aquaponics, hydroponics or aeroponic techniques. All of these are methods used in controlled environments, with various factors such as the water flow, lighting control, temperature, and substrate controlled by the farmer, unlike traditional farming practices.
Vertical farming has many benefits
The most obvious benefit of vertical farming is maximised land use. This method allows farmers to grow more crops in a smaller footprint, making it ideal for areas with limited land availability. But there are other benefits too:
Production throughout the year: Since the environment of vertical farms are more controlled, it is possible to cultivate a crop more than once a year, or to ensure that you have a consistent yield throughout the year – depending on the crop type of course. Any seasonal constraints are removed and production is more efficient.
Water conservation: Less water is used in these systems.with only the precise amount of water needed to provide the plants with sustenance. Where farms are located in greenhouses or indoors, less evaporation also occurs.
Low environmental impact: When less space is needed to grow more food, there is a lower impact on the environment. Less natural vegetation needs to be cleared to accommodate soil based farming.
Improved control over growing conditions: When coupled with greenhouse systems, factors such as light intensity, temperature and humidity can be regulated. However, the plants are more dependent on the farmer to provide nutrients as there is little to no soil used as a substrate. Farmers can exercise strict control over when which fertilisers are used.
How to start a vertical farm
If you are looking to start a vertical farm, you need to first allocate space. You will need a space to put up the vertical structures where it has ample natural light, and where the structures can be safe from animals. People often want to put vertical gardens in warehouses and storerooms, but it is very costly to provide enough artificial lighting to try and make up for the lack of sunlight.
If you plan on adding ventilation to a greenhouse, temperature control systems or any other high-tech additions, remember to consider access to electricity or solar power. If solar is your choice, take note the for every hectare of artificial lighting you may need up to five hectares of solar panels to provide enough electricity.
There also needs to be a space where you can add drainage so access water can drain from your vertical farm.
Next, you will need to look at the crops you would like to grow as this will determine your growing method.
Structures for vertical farming:
Vertical wall gardens
Vertical wall gardens are one of the simplest and most cost-effective ways to start vertical farming in cities where you have walls, and limited horisontal space. You can use recycled materials such as old pallets, wooden crates, or plastic bottles as planting containers. These containers can be attached to a vertical frame or wall, creating a vertical garden. This method is excellent for growing herbs, small vegetables, and even certain fruits like strawberries.
Tower gardens are vertical systems that allow plants to grow in stacked layers. PVC pipes can be used to create vertical planting towers. Plants are placed in holes drilled into the pipes, and a water and nutrient solution is circulated through the system. PVC pipes are relatively inexpensive and can be found at local hardware stores. Tower gardens are suitable for growing a variety of leafy greens and herbs.
Hanging gardens are an excellent option for small spaces. You can use hanging pots, recycled containers, or even fabric pouches attached to a frame or railing. These hanging containers can be filled with a lightweight growing medium and used for cultivating herbs, lettuce, and other compact crops. Hanging gardens utilise vertical space effectively and are relatively low-cost to set up.
Hydroponic systems, where plants are grown in water without soil, can be affordable if you opt for a simple DIY setup. You can create a basic raft system using foam boards floating on a nutrient solution. Alternatively, a wick system, where a wick draws nutrient solution from a reservoir to the plants, is inexpensive and easy to set up. These DIY hydroponic systems are suitable for growing various vegetables and herbs.
As the name suggests, shelves are used to create rows of vertical gardens. Similar to wall- or hanging gardens, containers with substrate is used keep the plants in. Pots or trays are stacked on the shelves in a tray of water or are connected to driplines that provide the plants with water.
Planting a (vertical) garden and watching it grow
Some crops are not compatible with vertical systems – do not try to plant maize or pumpkins in this system. But there are still a multitude of other crops that can be used. Here are a few you can research:
Herbs such as basil, cilantro, mint, thyme, and parsley are vital flavours that are in constant demand. They require relatively little space and grow well in vertical systems. Additionally, herbs are high-value crops because they have a quick turnover, allowing for multiple harvests throughout the year.
- Salad greens
Leafy greens like lettuce, spinach, arugula, and kale are popular choices for vertical farming. They are not only nutritious but also have a short growth cycle, making them ideal for continuous harvesting. Salad greens are versatile and are used in various culinary dishes, making them high in demand and a profitable choice for vertical farms.
Microgreens are young edible plants harvested at an early stage. They are incredibly popular in high-end restaurants and farmer’s markets due to their intense flavour and high nutritional content. Microgreens can include varieties like radishes, mustard greens, and pea shoots. Despite their small size, microgreens are considered high-value crops because they can be sold at a premium price.
Strawberries are a popular fruit that can be grown vertically in towers or hanging systems. They have a relatively high market price and are favoured by consumers for their sweetness and freshness. Vertical farming allows for efficient use of space, making it possible to grow a significant quantity of strawberries in a small area.
- Gourmet mushrooms
Gourmet mushrooms such as oyster mushrooms, shiitake, and maitake have gained popularity in culinary circles. They can be grown vertically in specially designed containers or shelves. Mushrooms have a relatively high market price, making them a profitable choice for vertical farms.
When choosing high-value crops for your vertical farming system, consider the local market demand, climate suitability, and your expertise in cultivating specific crops. Conduct market research and engage with local chefs, restaurants, and grocery stores to understand their requirements and preferences. By selecting the right combination of high-value crops, you can optimise your vertical farm’s profitability and contribute to the sustainable growth of your agricultural venture.
For emerging farmers in sub-Saharan countries, vertical farming represents a pathway to overcome traditional agricultural challenges and create a more sustainable, efficient, and profitable farming enterprise. By harnessing the benefits of vertical farming, these farmers can contribute significantly to the local economy, local supply chain and food security.
J.M. and Marsh, J. (2022) How Africa can develop its own version of Vertical Farming, Agrilinks. Available at: https://agrilinks.org/post/how-africa-can-develop-its-own-version-vertical-farming
Vertical farming in Africa with Tower Farms (2022) Agrotonomy. Available at: https://agrotonomy.com/vertical-farming-in-africa-with-tower-farms/
Vertical Farming South Africa: 4 companies making a big impact (2022) Indoor Grow Farmer. Available at: https://indoorgrowfarmer.com/vertical-farming-south-africa/#:~:text=Vertical%20farming%20in%20South%20Africa,conditions%20to%20accommodate%20vertical%20farming.
B.Bugbee (2015) Why vertical farming won’t save the planet. www.youtube.com/watch?v=ISAKc9gpGjw&feature=youtu.be