Advantages of Greenhouse Farming in Africa

 

A greenhouse is a building with walls and a roof made mainly of transparent or translucent material, like glass or plastic (usually polyethylene or polyvinyl), designed for the in-door cultivation of crops. The frame is usually built with wood or metal (usually aluminum or galvanized steel). Greenhouses are used for the production of vegetables, flowers and fruits. Growing vegetables and fruits in a greenhouse offers a good number of advantages, especially in Africa. The continent is still a net importer of food despite possessing 60% of the world's uncultivated arable land. 

Africa can significantly increase its food production with the greenhouse technology. Africa currently accounts for less than 5% of area dedicated to protected agriculture in the world, while China accounts for most of the area dedicated to the cultivation of vegetables in plastic greenhouses. Greenhouses are one of several forms of protected agriculture. The following are the advantages of using greenhouses:

1. Off-season crops can be grown

A farmer is able to control temperature and humidity inside a greenhouse which allows for the cultivation of crops which require specific climatic conditions to thrive. In Africa, it is even possible to grow crops that would only do well in the temperate zones, such as strawberries. In Senegal, 31-year-old Thierno Souleymane Agne has demystified strawberry cultivation, producing them on a large scale thanks to greenhouses. He started producing strawberries in 2016. His company Fraises-Sen produces sweet and 100% organic strawberries all year round.

In Cameroon, GreenHouse Ventures CEO Roland Fomundam has begun growing strawberries on a large scale in his greenhouses, and will put his harvest on sale in coming months.

2. Better quality crops and increased crop yield

In greenhouses, plants are not stressed by extreme temperatures and harmful humidities. As such, the plants do not need to deploy energy to protect themselves from these harsh conditions. The energy is rather channeled to improve its growth, leading to better qualities and quantities. Samson Mwaikenda, a greenhouse farmer in Tanzania started greenhouse farming in 2017 and has been able to make his tomato cultivation much more profitable. In October 2016, Raphael Ngari, a Kenyan farmer harvested 3,400kg of spinach from his 8m by 30m greenhouse, while a similar population of the spinach in an open field yielded 700kg. Ngari was able to get more than four times more with the greenhouse technology. With greenhouses, farmers can grow more crop cycles than with open field farming, and attain much more yield per crop cycle. Tomato greenhouse farms have an average annual yield of 200 t/ha of tomatoes, while tomatoes grown on open fields average 7 - 30 t/ha of produce annually.

 

3. Greater protection against extreme weather conditions

With open field cultivation, there's the risk of losing a good portion of a harvest or an entire harvest due to adverse weather conditions. Harsh weather conditions like strong wind and ultraviolet rays from the sun are a threat to the healthy growth of plants. In the horn of Africa, in Berbera (Somaliland) for example, temperatures go as high as 45 degrees Celsius and winds are very fierce. Seawater Greenhouse, a UK-based company specializing in the development and construction of greenhouses in arid environments, was able to deploy a greenhouse in Berbera which utilized evaporatively-cooled shade net structures, allowing the greenhouse to capitalize on the use of hot climatic conditions to fuel the process. In some countries, greenhouses are designed to be storm-resistant.

Changing climatic patterns are affecting many farms, and farmers need to be able to protect their crops from periods of extensive or delayed rainfall. The drip irrigation system used in greenhouses is a solution to that problem, as they provide steady, controlled and adequate water supply.

4. Greater control of pests and diseases

Vegetable production in sub-Saharan Africa is largely affected by pests, with new insect pests coming up. Pests like the tomato leaf miner have caused up to 100% yield losses in some regions. In Africa, we mainly rely on the use of chemical pesticides for pest control, which is detrimental to both the environment and human health, and the pests develop resistance to these pesticides at some point. For this reasons, the use of chemicals is not sustainable. Greenhouse farming provides a shield from outdoor pests and diseases. They also allow for the use of lower doses of healthy plant protection products, unlike the high doses of chemical pesticides that are used on crops grown in open fields.

5. Less farmland required

A greenhouse can be set up on as little as 20 square meters (a 4 x 5m mini greenhouse at home). Greenhouses in Africa can be of varying sizes. Some greenhouse sizes are listed below. Note that other dimensions exist.

• 4 x 5 m (20 square meters)
• 6 x 10 m (60 square meters)
• 6  x 12 m (72 square meters)
• 6 x 15 m (90 square meters)
• 8 x 15 m (120 square meters)
• 8 x 25 m (200 square meters)
• 8 x 30 m (240 square meters)
• 8 x 45 m (360 square meters)
• 8 x 65 m (520 square meters)

About 1,000 square meters (1 ha) of land is required for small-scale open field family farming, while about 400 square meters of land would be required for small-scale greenhouse farming.

6. Saving of resources

Water is a critical input in farming - both indoor and open field farming. However, the quantities required by these systems of farming differ a lot. With greenhouses, little water is used, which translates to less expenditure. Greenhouses save water through closer crop spacing, shorter crop cycles, drip irrigation, and reduced evapotranspiration rates in the greenhouse. A shorter crop cycle means plants need water for a shorter period of time. A farmer growing tomatoes in a greenhouse would use approximately 61% less water than the farmer growing tomatoes in an open field farm.

Owning a greenhouse requires some capital investment, but the returns from the greenhouse are worthwhile and the returns on investment always high. Moreover, most greenhouses are designed to last for at least five years, and some last for up to 10 years.