Vertical farming is the practice of growing crops on vertically stacked layers rather than on horizontal surfaces. This means growing crops on top of each other which allows for conservation of space and ability to easily control the growth of the crops and so produce more on less space.

Vertical farms can be both indoor and outdoors. Growing indoors calls for a more controlled environment such as light, water and temperature

history of vertical farming

The Babylonians were the early innovators with their hanging gardens. They were described as one of the Seven Wonders of the Ancient World listed by Hellenic culture. Built more than 2500 years ago, they were a prototype to modern vertical farming.

Over 1000 years ago, the Aztecs civilization also pioneered a form of hydroponic farm by building floating gardens on water called Chinampas. The Chinampas were built as made of rafts of rushes and reeds, put together with tough roots.  The Aztecs then dredged up soil from the shallow bottom of the lake, piling it on the rafts.  The soil that came from the bottom of the lake was rich in a variety of organic debris, decomposing material that released large amounts of nutrients. They planted vegetables, flowers, and even trees on this rich soil.  The roots of these plants upon growing would push through the floor of the raft and down into the water.

As recent as the 17^th century a more technologically advanced form of vertical farming was introduced by the French and Dutch farmers who wanted to grow warmer-climate fruits in winter. They did this by growing their fruits against stone walls that retained heat, creating their own microclimates.

Modern vertical farming take many forms and are done both at small scale and commercially.

The first known introduction was in 1915 by Gilbert Ellis Bailey coined the term “vertical farming” and wrote a book titled “Vertical Farming”. In the early 1930s, William Frederick Gerick pioneered hydroponics at the University of California at Berkley.

In the 1980s, Åke Olsson, a Swedish ecological farmer, invented a spiral-shaped rail system for growing plants and suggested vertical farming as a means for producing vegetables in cities.

The modern concept of vertical farming was proposed in 1999 by Professor Dickson Despommier as a solution to food security in cities. It was at this time that Vertical farming was officially conceptualized as cultivating and producing crops in vertically stacked layers and vertically inclined surfaces.

TECHNIQUES OF VERTICAL FARMING

1. Hydroponics

It is a method of growing food in water using mineral nutrient solutions without soil. The basic advantage of this method is that it reduces soil-related cultivation problems like soil borne insects, pest, and diseases.

Hydroponics operates under a very simple principle that says, provide plants exactly what they need when they need it. Nutrient solutions are administered tailored to the needs of the plant being grown in a controlled environment such as exactly how much light the plants receive and for how long monitoring and adjusting pH levels accordingly leading to accelerated plant growth.

• Aeroponic Farming

The National Aeronautical and Space Administration, USA (NASA) invented this technology to find an efficient way to grow plants in space in the 1990s.

Aeroponics does not require any liquid or solid medium to grow plants. Plants are tied to and suspended to a support in a misted air chamber. The roots are sprayed with nutrient solution. This method requires very less space, very less water and no soil.

Aquaponic farming

The farming system is a combination of aquaculture, which refers to fish farming, and hydroponics—the technique of growing plants without soil, to create symbiotic relationships between the plants and the fish.

Nutrient-rich waste from fish tanks serves as “fertigate” to hydroponic production beds which function as bio-filters that remove gases, acids, and chemicals, such as ammonia, nitrates, and phosphates, from the water.

The gravel beds of the aquaponics provide habitats for nitrifying bacteria, which promotes nutrient cycling and water filtering. Consequently, the freshly cleansed water can be recirculated into the fish tanks.

Vertical bag farming for the smallholder farmer in Kenya

Small holder farmers face many challenges, one of them being the ever-decreasing land size. Vertical farming solutions offers them an alternative. The REAL IPM company in Kenya has produced a vertical bag that are made of durable UV protected bags pre-punched with holes that increases production of leafy vegetables up to six times per square metre.

How to set up a Vertical Bag Farm

Vertical bags will be used to produce leafy vegetables for around 9 months of the year before changing the planting material. It is therefore important to get it right at the beginning. To get the growing media right at the beginning

There are different bag sizes as shown below.

The following methodology is adapted from the Real IPM Vertical bag guide:

INPUTS	LARGE BAG	STANDARD BAG	SMALL BAG
MANURE	8 Wheel barrows	6 Wheelbarrows	1.5 Wheelbarrows
SOIL	8 Wheel barrows	6 Wheelbarrows	1.5 Wheelbarrows
LIME	3 kgs	2 kgs	1 kg
DAP	3 kg	2 kg	1 kg
Tricoderma	1 satchet	1 satchet	1 satchet

Steps

1. Mix the soil and manure.

• Add DAP (3 kg) and lime to the mixture.

• Thoroughly mix the bag media ingredients.
• Spread the bag to identify the top, bottom and outer sections.
• Turn the bag inside out and gather it in the middle part of the bottom part.
• Place the bag on the ground right side out.
• Start filling the bag with the mixed media.

• Ensure you have a stable base at the bottom and that all holes are visible.
• Continue filling your bag untill you have a well filled upright bag.
• Wet the bag with 30 litres of water and start planting on the sides of the bag.
• Place the curled section of the 16 mm riser pipe fitted with button drippers on the top of your bag.
• Plant leeks, corriander, lettuce, carrots etc on the top section and you have your very own bag garden.