Greenhouse Farming in Kenya
Greenhouse farming in Kenya is a type of farming where plants are grown in a covered structure with PVC paper on the roof for ventilation purposes, a net-like material is used on the sides. This makes sure that the air circulation is good. This type of structure is used to create a conducive environment for the plants to grow. It aims at controlling the conditions that determine crop productivity such a sunlight, temperature, rainfall etc. This makes the crops immune to weather fluctuations.
Some of the greatest challenges when growing open air plants is weather unpredictability. Lack of rainfall at crucial points in the life of plants will bring losses to farmers. Greenhouses tackle this by using another farming technique known as drip irrigation, this we shall look at as the second technology.
Greenhouses improve productivity by making sure that plants are harvested for the entire duration of its maturity rather than just a short time with open air farming. A greenhouse can bring In as much as ksh 400,000 in a season making it a very profitable investment.
Greenhouse Farming in Kenya – Amiran’s Support to Farmers
Amiran Kenya’s agro-division has made great strides in the greenhouse technology since its inception in 1963. The firm has introduced new innovations in the agriculture, uplifted the standards of farming in Kenya and helped growers develop markets for their produce.
In 2009, Amiran Farmers Kit was developed. The kit has grown widely popular around the country, including the arid and semi—arid areas, as it offers a complete solution to small scale growers who get to enjoy simpliﬁed modern inputs at one go. In addition, the kits come with training and farm support from Amiran extension officers.
The farmer’s kit has two components – a greenhouse and an open – ﬁeld option. Thus, a farmer can segment his farming and decide which fruits and vegetables he will grow in the greenhouse, and which he will grow outside.
Fruits and vegetables that have recorded success in the green houses include tomatoes, cucumber, kales, green peppers, avocado and herbs among others.
Before its launch, the farmer’s kit was introduced through a pilot project that was supported by research. A demonstration plot was set up at Amiran’s headquarters in Embakasi, Nairobi. Today, hundreds of farmers are beneficiaries of the invention. In addition, primary and secondary schools, colleges, polytechnics and universities around the country have adopted the concept, enhancing and securing their food supply in the process.
Today, the farmers’ kits have been incorporated into the curriculum of some schools to give students practical skills while imparting knowledge in agriculture and demonstrating that it can, indeed, become a successful business.
The project has received wide-spread support from the Government, the European community, charitable organisations like Kenya Red Cross, international agencies, NGOs and community based organisations and leaders. Many have sponsored the installation of the kits to academic institutions, and given funding to women and youth groups around the country to buy the kits and start agri-businesses.
The Embassy of Israel in Kenya, for instance, has teamed up with Amiran and donated several kits to Women’s groups and schools in various parts of the country.
Greenhouse Farming in Kenya – Factors Affecting Greenhouse Farming
Some of the challenges that affect the success of greenhouse farming in Kenya include:-
Temperature And Humidity
Many farmers fail to get good profits from greenhouse crops because they cannot manage the two important factors that determine plant growth and productivity. Greenhouse temperatures below 13 degrees Celsius and above 30 degrees Celsius in the case of dry air or higher than 30 to 35 degrees Celsius in cases of high air humidity affect growth and productivity of most crops. The optimal temperatures for production of greenhouse tomatoes, pepper and eggplant should be 15 to 30 degrees Celsius and not beyond 35 degrees Celsius.
The temperatures should be maintained at around 16 to 30 degrees Celsius during the day and 13 to 18 degrees Celsius during the night.
Some tomato farmers close the greenhouses the whole day without ventilation resulting in excessively high temperatures beyond 40 degrees Celsius that lead to reduced performance of the crops. Generally, small-scale greenhouses are prone to overheating when the sun is too hot.
Farmers should, therefore, open the doors and sides of the greenhouse from 8am to 5pm for ventilation and close them at night to reduce heat loss. Greenhouses with only insect nets on the walls are unsuitable for areas with low temperatures like the highlands of Kericho, Mau Narok, Molo and Mt Kenya regions but may have positive effects in hot and warm areas such as Mombasa, Kitui, Kisumu, Machakos and Garissa. Ideally, farmers should have a thermometer for measuring temperature inside the greenhouse for effective management.
High relative humidity resulting from crop transpiration, water evaporation from the humid soil or other growing media and condensation of water vapour on the different greenhouse surfaces is another challenge.
Relative humidity above 80 per cent coupled with high temperatures increases incidences of bacterial and fungal diseases like bacterial wilt and botrytis (gray mold) while greenhouse conditions with relative humidity below 60 per cent and high temperatures create favourable micro-climate for rapid multiplication and development of mites and insect pests.
Humidity in the greenhouse should, therefore, be regulated by ensuring adequate ventilation, maintaining high temperatures at night, using plastic mulching on planting beds and avoid wetting of the greenhouse floor.
Loss of Soil Fertility
This is a common problem as most farmers plant one crop continuously without rotation. This can be overcome by rotating crops, for example growing onions or melons, pepper or eggplant after tomatoes and the use of both organic and inorganic fertilisers to replenish soil fertility.
Farmers can also replace greenhouse soil by bringing quality soil from outside. Adopt the technology of growing crops in pots or soilless cultures. The soils when used continuously with same crop will have a buildup of diseases, especially bacterial wilt, bacterial canker, fusarium and verticilium wilts.
Greenhouse farmers are, therefore, encouraged to treat the soil by sterilisation, solarisation or fumigation using fumigants such as Dazomet, Metam Sodium and Chloroptin.
Greenhouses get contaminated by people visiting the structures or by use of infected planting material, water and farm tools. Have a foodbath at the entry.
Lack of Quality Water Sources
Many parts of the country are deficient of good water sources and rivers or boreholes may also be absent. In addition, available water could be saline, chlorinated or contaminated with diseases like bacterial wilt, hence it is of poor quality.
Contaminated water is common in areas where farmers in sources of water plant crops like potatoes, tomatoes and water flowing downstream is collected by farmers for greenhouse farming. This introduces bacterial wilt in greenhouse tomato.
Pests and Disease
Management of insect pests and diseases is the biggest challenge in greenhouse farming. This depends on the type of the crops that are planted. However, generally, pathogens and insects can be established in a greenhouse very fast. They are very difficult if not impossible to get rid of effectively. For greenhouses that are covered with plastic, the use of ultraviolet-absorbing plastics can reduce insect problems.
Cost of setting up greenhouses
Setting up a greenhouse and the systems that go with it is expensive and posses the greatest challenge to many people who would like to get into greenhouse farming. Commercial banks offer credit facilities but they require collateral to act as security which in most cases are usually not available and also the interest rates charged on this loans make the loans unattractive.
Greenhouse Farming in Kenya – Advantages/Benefits
- Increase in yields depending upon the type of greenhouse, type of crop, and environmental control facilities.
- Reliability of crop increases in green house cultivation.
- Expands the growing season.
- Expands the variety of crops to be grown.
- Minimize external threats to crops.