We say that agriculture is both an art and a science. The art part involves the building of structures and the making of various tools and implements. Science involves the growth of the crops and the various practices involved in the process. Art and science are not limited to the mentioned activities.
More than 75% of plants, either food crops or cash crops are grown in open field. The crops grow under natural environmental conditions.
Greenhouse Technology is defined as the technique of providing favourable environment condition to the plants. It is rather used to protect the plants from the adverse climatic conditions such as wind, cold, precipitation, excessive radiation, extreme temperature, insects and diseases. It is also of vital importance to create an ideal micro climate around the plants.
Greenhouses are framed structures(with timber, metal or plastic) covered with transparent or translucent material(Mostly polythene) large enough to grow crops under partial or full controlled environmental conditions to get optimum growth and productivity.’
Inside the greenhouse the ground is fitted with drip lines/pipes that are used to irrigate the plants. Water drops on the base of each plant. The pipes may also be used for fertigation where fertilizer is dissolved in water and fed to the plant through the pipes.
High hygiene measures are observed in the greenhouse to avoid contamination or the introduction of any pathogens and foreign material into the greenhouse. Entry and accessibility into the structure is always controlled and only the authorised are allowed in.
Most greenhouse users usually plant high value crops in order to maximize on quality as they lower the production cost hence realizing higher profits. These crops mainly include vegetables and flower crops.
Reliability of crop increases under greenhouse cultivation. The yield may be up to 10-12 times higher than that of outdoor/open field cultivation depending upon the type of greenhouse, type of crop, environmental control facilities. Since they don’t rely on seasons, these structures enable even off-season production of crops.
Greenhouses also allow for efficient utilisation of chemicals, pesticides to control pest and diseases. Water requirement of crops very limited and easy to control.
In Kenya, greenhouse farming has been greatly adopted and is used in both small scale and large scale farming in various parts of the country.
The presence of these structures has given birth to modern techniques of Hydroponic (Soil-less culture), Aeroponics and Nutrient film techniques which play a vital role in the horticulture and floriculture sector.