IRRIGATION IN KENYA
The total area equipped for irrigation for Kenya was initially 23,000 hectares. The total area equipped for irrigation in Kenya increased from 23 thousand hectares in 1968 to 151 thousand hectares in 2017 growing at an average annual rate of 4.00%.
Irrigation is the artificial application of water in a controlled amount to encourage the growth of plants. Irrigation involves the application of water according to plant requirements.
Several factors contribute to the under performance of the agricultural sector’s growth. These include( source Kenya Irrigation Market Brief)
- Land and water scarcity, conflicts, particularly in the Arid and Semi Arid Land areas, and limited farming land.
- Frequent drought leading to rapid depletion of some of the water resources, with a devastating impact on agricultural economies and livelihoods.
- Poor agricultural extension and irrigation water management-related service delivery, particularly for small-scale farmers; irrigation service providers and NGOs are expanding extension networks, but services remain limited outside core commercial agriculture districts.
- Low access to affordable credit and capital investment; some commercial banks are addressing these issues and private-public partnerships (PPPs) are emerging between financial service providers and irrigation dealers.
- Weak farmer organizations and associations, including water user associations; some donors run technical programs aimed at strengthening farmer organizations.
- Inadequate storage and lack of post-harvest facilities, poorly organized markets, and lack of processing and other marketing infrastructure; the Government and a number of donors are addressing, in particular, the issue of cold storage.
- Lack of access to technical and market information (leading to high transaction costs); web-based and phone-based services have been developed to bridge the knowledge gap created by the reduced presence of public sector extension services. In addition, private service providers (irrigation dealers, private agribusinesses) are increasingly providing technical assistance on technical and marketing issues.
- Poor road infrastructure to potentially irrigable Arid and Semi Arid Lands areas, limiting both operational and input/output market access.
Factors that promotes irrigation in Kenya
- Explicit policy support for the expansion of irrigation
- Good experience in high-value irrigated agriculture by the existing private commercial farms
- Favorable climatic conditions, with a potential for high-tech efficient irrigation, when water is available
- Availability of irrigable areas endowed with adequate infrastructure, and proximity to input and output markets
- Domestic and regional market deficits in many food products • Less than 50 percent of irrigation potential currently developed
- Availability of local agricultural lending banks, cooperatives,
Factors required in any field of irrigation
This includes water quantity (stream size, volume, and duration for which the supply is available) and quality of water, the type of water resources i.e. bore/tube well; open dug well, reservoir/pond/tank or river and location of the water resource.
The size and shape of the area to be irrigated, soil type for its texture and irrigation properties (field capacity, wilting point, bulk density, allowable depletion level) including infiltration rate, and topography of the land
The climatic data required for the computation of crop water requirement.
Crop type, sowing/planting, and harvesting period, crop coefficient, fertilizer requirements, crop morphology. In general following guidelines can be used to ensure an adequate quantity of available water for the supply of irrigation water to the wide-spaced (orchard) and close-spaced (vegetable etc.) crops.
However, the area to be irrigated can be decided based on water availability and crop water demand.
labor availability dictates the type of irrigation method to be practiced. Large labor-intensive irrigation projects require skilled labor and non-skilled personnel to carry out the daily routine on the farm.
Some irrigation methods require high capital to initiate thus the farmer is encouraged to choose the type of irrigation method depending on his/her budget.
It is a wish of many farmers to maximize their profits from selling out their products thus the market availability is the main determinant of profit maximization.
Method of irrigation in Kenya
There are various types of irrigation practiced in Kenya. These types of irrigation are determined by the water quality and quantity, land resources, climatic conditions, labor and market availability, farmer’s budget and the type of crop to be planted.
The existing method of irrigation in Kenya available includes:
- Overhead irrigation
- Drip irrigation
- Basin/ flood irrigation
- Furrow irrigation
- Border irrigation system
OVERHEAD IRRIGATION IN KENYA
The common method of overhead irrigation in Kenya is the sprinkler irrigation system. Sprinkler irrigation is yet another common irrigation system that you could install on your farm to compensate for the low rains that Kenya has been experiencing for quite some time.
A sprinkler irrigation system can be termed to be the opposite of a drip irrigation system.
The sprinklers rotate, distributing water to the plants on your farm from above. However, rest assured that you will find a variety of sprinkler irrigation systems from major irrigation equipment suppliers in Kenya like Eunidrip Irrigation System.
Sprinkler irrigation system is may be used for many crops like maize, beans, vegetables, and other types of plants that require much water on different types of soils in various types of land slopes.
The system is best suitable for irrigating sandy soils at different slopes. This is because sandy soils have high filtration rates thus much water is needed to irrigate the land.
Sprinkler irrigation is best suitable for shallow soils that do not require proper leveling, areas with steep slopes with high washing of soil .i.e. erosion, and high valued crops.
Advantages of a sprinkler irrigation system
- Much water saving since side movement or percolation of water can be avoided by constructing terraces.
- Land leveling is not necessary thus reducing the leveling costs.
- It can be practiced in areas with non-uniform slopes.
- It can be practiced in areas where water is limited or scarce.
- Pesticides and chemical applications can be done together with the routine application of water.
- Uniform application of water can be made in high porous soils.
Disadvantages of overhead irrigation in Kenya (sprinkler irrigation)
- Higher potential for evaporation and wind drift issues compared to drip
- Waters both crops and weeds
- Cannot be used on crops susceptible to foliage diseases
Higher potential for runoff and erosion compared to drip
Precautions required while installing a sprinkler irrigation system
These are the points in which the farmer must consider before installing the sprinkler irrigation systems to ensure proper budgeting and operation of the system.
- Sprinkler irrigation system requires clean water to prevent the blockages of sprinkler nozzles.
- It requires high technical personnel to operate and maintains the system.
- Areas with strong wind are not advisable. This because the wind strength can blow away the system
- Pipe laid on the soil can interfere with other farms of operation like plowing and harrowing purposes if not properly installed.
- The general operating cost is high.
Sprinkler/overhead irrigation system design.
These are the components of the system for the system to operate normally.
Screen or debris filter.
It is used when the surface water is the main source of water for irrigation. The main function of the screen is to filter out the large solid particles that may block the sprinkler nozzles.
When irrigation water is coming from streams, open ditches, and wells having silts, the desilting basins are used to trap out the silts instead of using the screen or disc filters.
Since the sprinkler irrigation water requires high pressure to provide water over the plants pumping unit is highly recommended to achieve this task.
The pressure forces the water through sprinklers or perforations or nozzle in the pipeline and then forms a spray. A high-speed centrifugal pump is used when the distance from the pump inlet to the water surface is less than eight meters.
For pumping water from deep wells or more than eight meters a turbine pump is highly recommended. The pumping driving unit may be either a motor or an internal combustion engine.
Piping and tubing.
The tubing consists of the mainline; sub mainline, laterals, and risers. The mainline conveys water from the source and distributes it to the sub mainline.
The sub-main lines convey water to laterals which in turn supplies water to the sprinklers. HDPE pipes and PVC pipes are usually used as main lines and sub mainlines for the buried and surface systems.
These are the pipe connectors that are used to quickly and easily join and disconnect pipes.
Pipe connectors should provide reuse and flexible connection, be watertight, be simple and easy to join and disconnect, be light, non-corrosive, and durable.
. Sprinkler head supplies water uniformly over the field without runoff or much water loss due to side movement or percolation.
Different types of sprinklers are available. They are either rotating or fixed type. The rotating type can be used in various applications and spacing.
Sprinkler heads are effective with the pressure of about 10 meters to 70 meters head at the sprinkler. The working pressure of most sprinkler heads range from 16 meters to 40 meters head is commonly used and practically achieved.
Fittings and accessories
The following are some of the important fittings and accessories used in a sprinkler irrigation system for connection and flow measurements.
- Water meters. It used to measure the amount of water delivered.
- Flange, coupling, and nipple used for proper connection to the pump, suction, and delivery.
- Pressure gauge. This is used to measure whether the sprinkler is working at the required pressure to ensure uniform water application.
- Bends, tees, reducers, elbows, hydrants, valves, and plugs.
DRIP IRRIGATION IN KENYA
The drip irrigation system is a type of irrigation that involves delivering water onto the soil at very low rates from small outlets fitted on to a drip tape also known as emitters. This is the major advantage of a drip irrigation system.
The drip emitters that are commonly used are the drip tape/line, button drippers, and arrow drippers.
The emitters ensure that water is directly delivered to the planted crops according to the farmer’s requirements or according to the manufacturer’s specifications.
The water drops slowly on the roots of the plants above the soil surface according to the placement of the mainline (the pipe that carries the irrigation water).
Different emitters on the best irrigation system have different flow rates (amount of water it discharges per unit time)This is what guides an irrigation engineer on the size of mainline to use when doing a specific design
It (emitter) also dictates the time needed to irrigate a specific size of a farm
In a drip irrigation system, we have a combination of equipment that is put together to make sure water is supplied to the plants so that only part of the soil is wetted unlike other types of irrigation systems which involves the entire wetting of the soil parts.
The advantage of a drip irrigation system is that it distributes water through a network of valves, pipes tubing’s and emitters which work in a well-articulated scientific model to offer high efficiency in power.
The main advantage of a drip irrigation system is to offer farmers the best possible economical water use while also keeping pumping costs low in case one chooses drippers instead of tapes.
For the drip irrigation system that uses the drip tape/line, there is no need for pumping unit since the pressure needed is low, the system utilizes the gravity.
When the gravity is considered, the height of the water storage for irrigation must be raised high to develop pressure to push water through the type.
Benefit/ advantage of drip irrigation in Kenya
- The drip irrigation system is the most efficient method of irrigation since water through emitters is directly delivered to the plant root zone hence economical on water usage.
- In a drip irrigation system, there is the constant benefit of water supply in small quantities to the plants thus creating the ideal moist condition for the proper growth of most plants.
- The drip irrigation system minimizes weed growth since water is only supplied to a particular crop root.
- The best drip irrigation system helps in the control of fungal diseases which grow very fast under moist conditions.
- Timeliness and labor-saving. In the best drip irrigation system, the control valves can be managed by one person to operate the whole system thus minimizing the labor costs hence minimizing production cost.
- Ease in fertilizer application. In best drip irrigation system, method of liquid fertilizer application known as Fertigation is very easy and fast since water emitters are used to directly distribute fertilizers to particular crop/plants
- Cannot get disrupted by wind
- Recycled non-potable water can be safely used.
- Moisture within the root zone can be maintained at field capacity.
- Soil erosion is lessened. This is because water is not flooded on the farm.
- Water distribution is uniform, controlled by the output of each emitter.
- Variation in supply can be regulated by regulating the valves and drippers.
- Foliage remains dry, reducing the risk of disease.
- Usually operated at a lower pressure than other types of pressurized irrigation, reducing energy costs.
Disadvantages of a drip irrigation in Kenya
- Relative high Initial cost for the purchase of drip components.
- Sun UV light is the challenge that scorches up the drip tubing or the emitters like arrow drippers thus shortening the lifespan of these tubing.
- Drip irrigation systems cannot be used for damage control by night frosts.
- The risks of degrading plastic affecting the soil content and food crops. With many types of plastic, when the sun degrades the plastic, causing it to become brittle, the estrogenic chemicals (that is, chemicals replicating female hormones) which would cause the plastic to retain flexibility have been released into the surrounding environment.
- If the water is not properly filtered and the equipment not properly maintained, it can result in the clogging of the drip emitters.
- For subsurface drip, the irrigator cannot see the water that is applied. This may lead to the farmer either applying too much water (low efficiency) or an insufficient amount of water
- Drip irrigation might be inappropriate for some fertilizer applications on some plants that require sprinkler irrigation for activation.
- Drip tape causes extra cleanup costs after harvest. Users need to plan for drip tape winding, disposal, recycling, or reuse.
- Waste of water, time, and harvest, if not installed properly. These systems require careful study of all the relevant factors like land topography, soil, water, crop, and agro-climatic conditions, and suitability of drip irrigation system and its components.
- Most drip systems are designed for high efficiency, meaning little or no leaching fraction. Without sufficient leaching, salts applied with the irrigation water may build up in the root zone, usually at the edge of the wetting pattern. On the other hand, drip irrigation avoids the high capillary potential of traditional surface-applied irrigation, which can draw salt deposits up from deposits below.
- The PVC pipes often suffer from rodent damage, requiring replacement of the entire tube and increasing expenses.
NB; rodents damage to the pipes can be controlled by using high-density polyethylene pipes (PE pipes) since they are stronger and structurally modified as compared to PVC pipes
Clearing of the bushes and application of the insecticides also keeps the rodents away.
FLOOD IRRIGATION IN KENYA
In flood irrigation, water is channeled to the field by use ditch or pipe and allowed to flow over the soil surface through the crops. Even though this method is simple, this irrigation type has negative effects on the crop and soil, using both water and labor inefficiently.
With flooding, only half of the applied water is used by the crop. The other half is lost to evaporation, runoff, infiltration of uncultivated areas, and transpiration through the leaves of weeds.
For this reason, wild flooding is mainly used on uneven terrains to irrigate pasture, hay, and small grains, which are not affected by sufficient water.
An important aspect to consider in wild flooding is that it’s a great solution to irrigate land that cannot be managed by other irrigation methods.
BASIN IRRIGATION IN KENYA
As the most common type of surface irrigation, basin irrigation is the most ancient and most simple irrigation types. Basin irrigation requires a leveled soil surface and a narrow ridge 15 centimetres to 50 centimetres high on all sides of the field which will serve as the basin.
This type of irrigation is used in the growth of paddy rice, herbs, and maize
The irrigated field is divided into smaller areas surrounded by small levees. Water is applied into each basin by various pipes and siphons, or through the levee. Water is removed from the field with surface drains on the low contour levee.
Basin irrigation is suitable for use on moderate to slow intake soils and deep-rooted, closely spaced crops such as maize, grains, cotton, or orchards.
Crops that do not tolerate flooding and soils subject to crusting can be basin irrigated by furrowing or using raised bed planting.
Despite its effective method of leaching salts from the soil profile into the deeper groundwater, basin irrigation does have some limitations:
- Leveling the field surface may create a financial and labor issue for the farmer
- Soil tillage is limited due to the small field area
- Levees can be easily destroyed by the entering of farm equipment into the field
- Challenging maintenance of narrow ridges (levees) along the field sides.
Basins range in size, from those designed to irrigate individual trees or small areas of vegetable crops, to rice paddies that occupy several acres.
BORDER IRRIGATION IN KENYA
Border irrigation is the type of flood irrigation which works on the principle of basin irrigation. Water is applied to the field through wide borders.
The area between borders is border strip, on which crops grow, and may range from 3-30 m (10-100 feet) in width. To manage border irrigation, the border surface must be leveled across its width so the water can spread uniformly across it.
Sloping borders are suitable for all crops, including grains, alfalfa, and tree fruits. Those that are sensitive to excessive water and soil that is too wet may not be appropriate to irrigate using this method
FURROW IRRIGATION IN KENYA
Furrow irrigation is an irrigation method in which water is applied from open ditches or pipes through small channels, or furrows, along the field. As water flows through the channel, it infiltrates into the soil, thus irrigating crops. According to furrow direction and level, they can be classified into:
- Level furrow (lengthwise leveled furrows)
- Contour furrow (furrows curved to fit field topography)
- Graded furrow (straight channels down the field slope)
Furrow irrigation is suitable for crops sensitive to too wet soil and excessive water over the stem. Furthermore, crops not suitable for flood irrigation can be irrigated with the furrow irrigation method.
Although this method doesn’t require special farm equipment and can minimize irrigation costs, furrow irrigation does have disadvantages. These include:
- Labor intensive
- High accumulation of salts in the furrows
- Difficult passing of farm equipment across the furrows
- Furrow surface needs to be leveled
- Requires experience on the part of the farmer to divide water into each furrow and to maintain the correct flow rate
- Difficult to automate the system.
BODIES ASSOCIATED WITH IRRIGATION SYSTEM IN KENYA
The irrigation system in Kenya is a governmental service that must be operated according to rules and regulations of the government.
For the efficient use of irrigation water without the conflicts from the surrounding individuals, the government of Kenya enacted the bodies under which the irrigation practices and water utilization are managed.
The bodies concerned with irrigation system in Kenya are;
- Water Resources Management Authorities (WRMA)
- National Irrigation Board (NIB)
WATER RESOURCES AND MANAGEMENT AUTHORITY (WRMA)
Water Resources and management Authority is mainly responsible for the allocation of water resources among the various competing needs like irrigation and livestock use. To manage this task, WRMA give permits to the individuals authorized to utilize water resources.
Functions of Water Resources and Management Authority, WRMA
- Protection of the water resources from excessive withdrawals, controls pollution, improves the water qualities in the country by integrating land use activities into its programs.
- Collects the water usage reports, analyze, store, and provides it when needed. The reports from WRMA are very critical for water distributions, investments, and decision making to enhance understanding of the climatic change.
- The Authority undertakes climate actions in terms of mitigation and adaptation to minimize the effects of global warming and climate change
NATIONAL IRRIGATION BOARD, NIB
National Irrigation Board (NIB) was established and incorporated in 1966 as a state corporation through the Irrigation Act CAP 347 of the Laws of Kenya.
The main reason which led to the creation of this body was to provide developments, controls, and improve irrigation schemes.
These public irrigation schemes in Kenya include Mwea, Bura, Tana, Ahero, West Kano, Perkerra, and Bunyala irrigation schemes.
National Irrigation Board in Kenya is a public society managed by the national government (government parastatal). This is the body in charge of all irrigation schemes management in Kenya.
Management of National Irrigation Board
- Chief Executive Officer
- Deputy General Manager, Irrigation and Infrastructure Development Services
- Deputy General Manager, Operations and Irrigation Management Services
- Deputy General Manager, Research Planning and Strategy
- Head of Human Resource and Administration
- Head of Internal Audit
- Head of ICT
- Head of Finance
- Head of Corporate Communication
- Head of Procurement
PRIVATE IRRIGATION COMPANIES IN KENYA
Private irrigation companies in Kenya are those companies that majorly deal with the supply, distributions, designs, and installation of irrigation equipment.
There are many of these companies available in Kenya. The latest information on the numbers of irrigation companies in Kenya is over 20 companies. These companies include:
EUNIDRIP IRRIGATION SYSTEMS
Eunidrip irrigation systems started in March 2014 with main objective of addressing sustainability in food security, poverty and financial instability in order to become leading irrigation equipment supplier in Kenya.
Season after season, we have worked side-by-side with both small and large corporate plantations to provide the right irrigation solutions as a leading Irrigation Equipment Supplier
A Eunidrip irrigation system is one of the biggest irrigation equipment suppliers. We deal with all irrigation equipment.
They include a drip system, overhead irrigation systems, flooding irrigation systems, dam and pond lining, green house and net house construction.
The drip system involves the provision of water below the plant stem by use of drip emitters which include button drippers, arrow drippers and drip tape.
The overhead irrigation system involves the provision of water above the crop leaves.
This overhead irrigation equipment supplier, we supply the rain gun sprinklers, regular or medium sprinklers and micro-sprinklers like misters.
As irrigation equipment supplier, we identify customer needs. These needs include the following;
- Climatic factors. – The quantity of the water applied to the farm depends with the quantity and duration of light intensity and humidity.
- Agricultural market demand and supply.
- Soil characteristics. – This includes water holding capacity of the soil, soil water intake rate and depth.
- Labor availability- best skilled and non skilled labor source should be checked before selecting any method of irrigation.
- Water quality and quantity. Water to be used for irrigation should not contain any matter which is harmful to crops to be grown the salt concentrations of irrigation water should be within the limits that can be tolerated by the crop to be grown.
- Energy availability and reliability.
- Economic status of the farmer.- cost of maintenance and expected life of cost of irrigation system includes annual return
- Crop type to be grown. – The output of the crop grown is highly affected by the method of water application and quantity delivered to the plants.
- Topographical conditions of the land .i.e. land slope. Topography has to do with location and elevation of the water supply sources with respect to the land boundaries, the area and the pattern.
Areas of specialization as irrigation equipment supplier
Under the drip irrigation supplier, we deal with an entire drip system which involves main HDPE pipes, sub-main lines, drippers (button drippers, arrow drippers and drip tapes of various pressure nominal), filtration units (disc and screen filters) control valves and the water tanks
On overhead irrigation equipment supplies, we are proud to be on top of the list. We stock various overhead irrigation equipment, which includes misters (G misters), medium size (three-quarter to one-inch sprinklers). Large sprinklers like rain guns and reel hose are also our area of specialty.
Micro irrigation equipment supplier
Micro sprinklers are emitters which spray water out to larger diameters than typical drippers or spray jets.
While the spray pattern is usually 360 degrees, at least one type is available with an adjustable arc between 30 and 330 degrees
The choice of micro-sprinklers depends on the size of the pumping unit. Water availability, type of the soil, type and the plant to be grown. The size of the farm is also a factor.
Big farms above an acre require the use of rain guns. Rain guns cover a larger radius of at least 25 meters.
Main pipes and sub-main lines as irrigation supplier
Main pipes is the pipes that draw water from the source either from lakes, streams, dams or water tanks.
As one of the irrigation suppliers, we stock various pipes of high-density polyethylene pipes, HDPE, of various diameters ranging from 16 millimeters to 63 millimeters.
Our main lines and sub-main lines are of pressure nominal, PN, of 6. This ensures easy work-ability.
The most common emitter is a dripper or button dripper, and emits water at a specific rate, usually between 1 liter and 2 liters per hour (lph).
Drippers are commonly used to water individual plants, and most drippers are color-coded so the user can easily identify the different flow rates.
Cleanable drippers have a removable cap to allow the user to remove small obstructions within the dripper. A dripper that is not cleanable would need to be replaced if it becomes clogged.
Pressure compensating drippers deliver a precise amount of water regardless of changes in pressure due to long tubing runs or changes in terrain elevations.
Eunidrip as the major irrigation equipment suppliers, we stock and supply various sizes of HDPE fittings of all sizes ranging from drip fittings which are drip connectors of 16millimeters, drip end caps, starters and drip takeoffs of all 16 millimeters, HDPE fittings of 32 millimeters to 63 millimeters of high-pressure nominal above PN 16.
The available fittings include;
- Male couplings i.e. with external threads of 16millimeters to 63 millimeters
- Female couplings i.e. with internal threads millimeters to 63 millimeters
- Middle connectors of 16millimeters to 63 millimeters
- Reducing coupling of all sizes
- P e elbows of all sizes from 16 mm to 63 mm
Eunidrip stocks various stock components of drip of various sizes. These components includes drip tapes, drip connectors, drip end caps, drip take offs and starters.
These components come with various sizes of 16 millimeters and 12 millimeters. But the commonly used drip components are of size 16 millimeters. This size (16 millimeters) enables large water discharge as compared to 12 millimeters.
Drip tape or drip line
Drip tape is the emitters used to efficiently and accurately deliver water droplets onto the plant roots. The emitters are pin-hole sized to minimize the loss of water and channel water directly to the required plant.
Drip tape types
Drip tapes vary in sizes depending with wall thickness, material type and the drip length. The drip tape come with different intervals of 10 centimetres, 15 centimetres, 20 centimetres, 30 centimetres and 40 centimetres.
The intervals are the spaces between the emitters. The emitters are usually single or double emitters. Double emitters are the best considered because of large water volume discharged from the main tubing.
Drip tape is made of plastic, polyethylene, and is sold flat on reels. The wall thickness typically ranges from 0.1–0.6 mm. Thicker walled tapes are commonly used for permanent subsurface drip irrigation and thinner walled tapes for temporary type systems in high-value crops
The drip tape is well designed to discharge one litter of water per hour. This discharge ensures water is efficiently and economically used
The economical water budget is the major determinant of the production cost. This dictates the type of plant to be grown. Broad leave plants require much water as compared to small leaved plants. This will affect the drip tape emitters to be used.
Drip lines are stock in form of rolls. The rolls contain different lengths of 1000 meters, 1200 meters and 1300 meters. The choice of the drip tape depends on farmer’s garden length, types of the plant to be grown and the economical budget.
Advantages of drip tape
- Extensive land leveling is not required, drip irrigation can be employed in all landscapes;
- Irrigation water can be used at a maximum efficiency level and water losses can be reduced to a minimum;
- Soil conditions can be taken into account to a maximum extent and soil erosion risk due to irrigation water impact can be reduced to a minimum;
- Fertilizer and nutrients can be used with high efficiency; as water is applied locally and leaching is reduced, fertilizer/nutrient loss is minimized (reduced risk of groundwater contamination);
- Weed growth is reduced as water and nutrients are supplied only to the cultivated plant;
- Positive impact on seed germination and yield development;
- Low operational costs due to reduced labor requirement, in particular energy cost can be reduced as drip irrigation is operated with lower pressure than other irrigation methods.
Take off is a plastic fitting that connects a main pipe with a drip tap They come in different sizes, but most common are mm(8 millimetre),12 mm(twelve millimetre) and 16 mm (millimetre).
Currently 16 mm (millimetre) takeoff is the most common in the market. They come in different designs and colors most takeoffs are complete black or may have a blue lock.
Standard takeoff can sustain a working pressure of up to 16 bars. Most of irrigation systems work at a pressure of three bar and below.
Drip valves are the connectors use in connecting the drip lines or drip tapes to the sub main line. Their uses are similar to irrigation takeoffs only that drip valve has a water controlling knob.
The common usage of drip valves is to control the entire flow of water through a specific drip line length.
This off and on operation of drip valves enable the independent use of the drip line. For instance, whenever there are leakages in a given drip line length, the operator just need to identify the line with the leakages and turn off the drip valves.
Operator will always proceed with the maintenance of the drip line length while the other remaining drip lines lengths are operating normally.
Drip valves are of different sizes depending with the type of drip line the farmer decides on. The available drip valves that we stock are of 16 millimeters and 12 millimeters. These are specifications that come with drip line to be used.
Drip line come with different colors codes. The common color codes are blue, red, yellow, black and green.
Specifications of drip valve connectors
- Working pressure of 50 K pa to 150 K pa.
- Rated water flow 1.38 l/h to 3.2 l/h
- Self flushing with anti logging performance
- Easy to connect and disconnect to both drip line and sub main lines.
- Highly resistant to UV rays.
- Commonly used with Low Density Polyethylene Pipes (LDPE) and High Density Polyethylene Pipe (HDPE).
- Internal diameters of 16 millimeters to 0.75 inch.
- Made of polyethylene material.
Drip valves usage
- Commonly used in green houses, net houses and open fields.
- When used in fertilizer application, it increases efficiency in application.
- Specific types are used for matching drip line (used as drip middle connectors).
Drip valves maintenance
- Frequent flushing with water to avoid particles blockages.
Shade nets are the upcoming synthetic fibers materials that are nowadays preferred in the construction of net houses, greenhouses and preparing seed nurseries.
They are mostly used in a broad variety of crops like blackberries, chives, and tomatoes.
Shade net percentages and their uses
Shade nets vary with light emission intensity. Light emission intensity is the amount of shade which the shade net provides to the crops under it.
The commonly used nets are categorized in terms of percentages. The available percentages commonly used are 90%, 75%, 60%, 55% and 50%.
For instance, 90% light emission shows that the net provides 90% shade thus cutting out 10% of the light from reaching the plants.
Nets also come in different colors ranging from white, black and green colors.
Nets provide protection from birds; provide uniform shadow to plants and to control air movement in greenhouses, net houses, and nurseries.
The nets are UV treated with resistant additives giving the net its good strength and durability.
A shade percentage of 30%-50% is ideal for vegetables and flowers.
Cost of shade nets
Light and heat emission of shade nets (percentages, %,) dictates the price of each shade net
Chives in shade net house. The shade net with higher percentages cost relatively high as compared to shade nets of lower percentages.
The cost of the shade net is not dictated by the color. The colors listed above mostly dictate the type of plant to be grown.
The commonly used cost method in the market is calculated by determining the square unit of the net. Thus the cost is multiplied by the square unit found.
Shade net sizes
Shade nets are available in sizes depending on widths and lengths. The commonly available widths in the market are three meters (3 m), four meters (4 m) and eight meters (8 m). Lengths available in the market are 50 meters and 100 meters.
Importance of shade nets
- It is easy to wash
- Do not get Decay
- Nets are easy to carry and easy to install
- Easy to relocate
- They are ideal for gardens, plant nurseries, home terrace gardening.
- Minimizes plant wind pressures to avoid damage to plants and enhances photosynthesis to stimulate plant growth.
- Conserves water
- Protects plants from pests and diseases.
GREEN HOUSE AND NET HOUSE CONSTRUCTION
Greenhouse construction in Kenya has been a lucrative business though many farmers make minor mistakes which can be corrected
Over the last couple of years, the world has been facing a Global food crisis, and Kenya is no exception.
The food insecurity in Kenya has been accelerated by drought and famine. That notwithstanding, the climate has changed drastically, and it’s mainly characterized by dry seasons.
Such situations lead to most farmers suffering because of poor soil nutrition and water shortages, which are poor conditions for food production.
As a result, farmers are now looking towards greenhouse construction in Kenya to allow them to grow crops during both wet and dry seasons.
Greenhouses have proven an effective alternative to increase productivity for both small scale and large scale farmers.
Besides, greenhouses can help improve their livelihoods and promote food security in Kenya. Farmers can construct either plastic-covered or permanent glass greenhouses that create a suitable environment for growing healthy crops all year round.
These structures promote the growth of crops by good irrigation systems, plus the temperature is mechanically controlled.
THE BENEFITS OF GROWING PLANTS IN A GREENHOUSE
Over time, farmers have come to realize that there are plenty of benefits of growing plants in a greenhouse, especially with the uncertainty in climate change lately.
However, before you carry out your greenhouse construction in Kenya, you have to conduct adequate research to ensure that you will reap some of the following benefits.
- A greenhouse delivers an extended growing season
- There are consistency and reliability in food production
- You can plant a variety of crops in a greenhouse
- It allows you to control the growth environment, humidity levels, and soil easily
- A greenhouse makes it easy for you to control insect and animal infestation
GREENHOUSE ACCESSORIES FOR GREENHOUSE CONSTRUCTION
Apart from the frame and exterior structure of the greenhouse, you need to know that there are accessories that have to go into a greenhouse to ensure that your crops grow as you would like.
However, the accessories you put greatly depend on your budget allocations as they could get pricey at times.
You need to consider what you really need in your greenhouse, and the accessories that you could place during your greenhouse construction in Kenya include a heating system, automatic vents, shelving, a fan, a mist system, and a rack among other accessories.
HOW DO YOU PREPARE FOR YOUR FIRST GROWING SEASON?
Now that you’ve already set up your greenhouse, including the accessories you want, you have to prepare for the growing season, but that also depends on the type of plant that you would like to grow in your greenhouse.
If it is your first time dealing with a greenhouse, then you need to start off with straight-forward crops instead of going for complicated crops without the experience.
You will find that most greenhouse farmers in Kenya start with vegetables such as tomatoes, carrots, leafy greens, and turnips among others.
It is also advisable for you to group together plants that have a similar growth cycle so that you can organize your planting season accordingly.
You should also know that not all the seeds that you plant will germinate. That’s why it is advisable for you to plant more seeds than you would expect to grow.
Doing so will help you save a significant amount of time, which you would otherwise spend transplanting.
On the other hand, if you are planting crops that climb vertically such as tomatoes, then you need to plant them on a raised platform on your greenhouse’s floor. A bench could also serve as a suitable alternative.
PUBLIC IRRIGATION SCHEMES IN KENYA
The table below shows the public irrigation schemes in Kenya with their locations, land acreage and the type of crops that are grown.
|Irrigation scheme||County||Area(acre)||Main crop|
|Perkerra||Baringo||1200||Horticultural crops and fruits|
PERKERRA IRRIGATION SCHEME
Perkerra Irrigation Scheme is situated 100 kilometers North of Nakuru near Marigat Township in Baringo South Sub-County. It derives its name from the River Perkerra, which is the source of irrigation water and the only permanent river in the region.
The construction of the scheme started in 1954 after several feasibility studies, which showed that the Perkerra plains were suitable for irrigation.
The last study was done in 1936 but due to financial constraints construction was shelved until the “State of Emergency” period, when detainees provided labor for construction purposes.
Marigat was one of the many detention camps in the country at that time.
The beneficiary population comprising of direct dependents is approximately 13,000 people. It also, indirectly, benefits the larger Baringo and including parts of Nakuru Counties.
Among all the Towns in Baringo County, Marigat is a leading generator of revenue of about KES 54 million annually. This is attributed mainly to irrigated agriculture.
Type of irrigation use
Gravity-fed open earth channel conveyance with an open furrow application system
Crops that are grown
Watermelon, onions, and vegetables
2. AHERO IRRIGATION SCHEME
The Ahero Irrigation Scheme is located In the Kano plains between Nandi Escarpment and Nyabondo Plateau.
The scheme was started as a pilot project to explore the feasibility of irrigation in the Kano Plains. Construction of the scheme started in 1966 and operations started in 1969.
Type of irrigation use
Crops that are grown
- Paddy rice
- Soybeans (seed)
- Sorghum and Cow peas.
3. MWEA IRRIGATION SCHEME
Mwea Irrigation Settlement Scheme (MIS) is located in Kirinyaga County and falls within two sub-counties i.e. Mwea East and Mwea West sub-counties.
The development of the scheme started in 1954 from the Tebere section with about 65 acres in irrigation farming and has since grown to the current area of 30,050 acres.
Out of these, 22,000 acres have been developed for paddy rice production while the remaining area is utilized for settlement, public utilities, and the growing of subsistence crops.
Since then, expansion has been done to the freehold area (referred to as out-growers) surrounding the scheme by a total of 4,000 acres; hence the total area under paddy rice production in MIS is 26,000 acres of irrigation farming.
The National Irrigation Authority (NIA) has improved, rehabilitated, and developed irrigation infrastructure for the farmers to engage in production activities.
The scheme lies along the drainage basins of Rivers Nyamindi and Thiba which supply the irrigation water.
There is still the potential of up to 10,000 acres for expansion within the surrounding areas. However, this is constrained by the lack of sufficient water for irrigation.
The scheme area is largely plane and predominantly covered with black cotton soils, with a few raised spots of red soil. Rice paddies have been developed on the low areas that are covered with black cotton soils while the high spots covered with red soils have been reserved for settlement and production of upland crops.
The current approach to scheme management is Participatory Irrigation Management (PIM), where the government through National Irrigation Authority and the farmers through their organizations (Irrigation Water User Association [IWUA], Mwea Rice Growers Multipurpose [MRGM] and Lainisha Sacco) have collaborated in management of the irrigation scheme. Each of the four i.e. the Authority, IWUA, MRGM, and Lainisha, have clearly defined roles in PIM.
The Irrigation Authority’s key responsibility in scheme management is the operation and maintenance of the primary and secondary infrastructure; while the farmers are responsible for the tertiary infrastructure.
Other roles include land administration, capacity building, irrigation expansion, and rehabilitation of the irrigation infrastructure.
4. BUNYALA IRRIGATION SCHEME
Bunyala Irrigation Scheme was started in 1959 with an initial 534 acres under paddy rice production. It has been under production since then.
Irrigation water is pumped from River Nzoia and flows by gravity through open earth channels to the farms. Due to increased demand for rice, two new pump sets were installed in 2005 and two more were also installed in 2007.
This brought the combined discharge to 1.2m3/s. With the widening of the main canal, the Scheme acreage was expanded to over 1,600 acres on the left bank of the river.
Type of irrigation use
Basin irrigation system
Crops that are grown
Pulses and Horticulture
5. WEST KANO IRRIGATION SCHEME
West Kano Irrigation Scheme is located in the Kano plains between Nandi escarpment and Nyabondo plateau on the shores of Lake Victoria in Kisumu County. The scheme was constructed in the year 1974 and become operational in 1976.
The scheme has 837 farmers with a gross area of 4396 acres. The gross farmland area is 2230 acres and farm size of 2-4 acres per farmer.
The scheme irrigation water is abstracted by pumping from Lake Victoria and water drainage is also by pumping back to the Lake. The scheme has a population dependent on about 30,000 people.
Type of irrigation use
Water is abstracted by pumping from Lake Victoria and water drainage is also by pumping back to the Lake.
5. TANA IRRIGATION SCHEME
Tana Irrigation Scheme is the oldest National Irrigation Authority scheme having started in 1953. The Scheme gazette area is 12,000 acres. The initially developed area was 900 ha (2,500 acres), and the scheme has a possible extension area of 12,000 acres.
The current area under irrigation is 4,700 acres with the current number of farming families (households) being 1,050 registered farmers therefore a population of about 6000 persons depends on this project for their livelihood.
The scheme collapsed in 1989 when Tana River changed its course and was revived in 2009, rehabilitation which was funded by the Arab Bank for Economic Development in Africa (BADEA) and the Government of Kenya.
Type of irrigation use
Water is abstracted through pumping, conveyed and distributed in open earth canal and applied through the furrow irrigation system
Crops that are grown
Cotton and other horticultural crops
6. KATILU IRRIGATION SCHEME
Katilu Irrigation scheme is located in Turkana County in south sub-county approximately 130km south of Lodwar town.
The project was started in 1966 but came to operation in 1970 through a joint effort of the Ministry of Agriculture who provided recurrent costs and the Food and Agricultural Organization (FAO) who provided capital cost and technical personnel.
The scheme is situated along River Turkwel; which is perennial, and irrigation water is diverted by gravity through the earth canal to the scheme.
The objective of the scheme was to settle some selected number of Nomadic families from famine camps in the County.
The scheme by then consisted of about 500 acres with each family allocated 1 acre as a tenant. The main crops grown were; maize, cotton, Okra, Sorghum, etc.
In 1982, the Ministry of Agriculture changed the irrigation system from Furrow to Basin system.
GROWING OF PLANTS USING SIMPLE IRRIGATION IN KENYA
Growing of plants under simple irrigation system is the currently used method in urban agriculture. Urban agriculture is the growing of plants in places where the land is limited and, crops/ plants are grown in consolidated or closed equipment.
The materials that normally used in urban agriculture may include, the hydroponics farming systems, aeroponics farming system, vertical gardening, use of pots and containers, sack and net planting.
HYDROPONICS FARMING SYSTEM
In hydroponics farming systems, the plants are grown using the solutions rich with nutrients without the use of the soil as the supporting medium.
This type of farming is very resistant to most weather conditions since the plants are highly protected from these elements. These protection and management provides excellent nutritional value and fasten growth of crops at minimal inputs. Here are a few hydroponic farming benefits.
Advantages of hydroponic farming
Excellent water utilization
Plants grown hydroponically use little water as compared to open field grown plants. This is due to recycling of the used water that have gone through the system and collected as the runoff water.
Faster growth of plants
Since the diluted nutrients are readily available, the energy that could be used by plants to garner in nutrients are converted into growth stimulation thus enhancing faster growth
Since plants are not in contact with soil as the medium, there will be no any weed.
Pest and diseases control
Plants are less vulnerable to soil-borne pests and diseases. This will lead to less use of insecticides and herbicides thus growing cleaner and healthier crops.
Applicable in space limited areas.
Plants nutrients requirements are provided and maintained in a portable system in your apartment, balcony, backyard or space rooms.
Plants roots spread out in search of nutrients but a hydroponic set-up, they will not spread out taking up space as they are provided with enough nutrients. One can grow plants much closer and utilize space.
2. AEROPONICS FARMING SYSTEM
Aeroponics is a modern system which involves growing plants in an air or mist environment without the use of soil or any aggregate medium.
In this type of farming, the plants are place in stem holding structure to suspend the plants in a closed or semi-closed environment. In this suspension state, the daggling roots are sprayed with water rich with nutrients.
The plant canopy (leaves and the crown) and the roots are separated by the plant support structure. Most of these support structure are either seed trays or foam compressed around the lower and inserted into an opening in the hydroponic chamber
3. SACK FARMING SYSTEM
Sack farming involves the growing of horticultural crops mainly the vegetables in the sack to maximize the vertical space. In this farming system, the majorly grown crops are the kales, spinach, onions, tomatoes and any traditional vegetables.
Sack farming involves the selection of the best soil that can be obtain from crop land fields, treated soil areas and any other place recommended by the agronomists. The selected soils are aerated to kill the soil borne diseases.
The aerated soils are then mixed with suitable crop nutrients in the correct proportion as required by the plants.
Areas where sack farming is important
- Investing in a traditional garden is too risky due to fear of expropriation or where individuals have no legal right to their land. By having a garden in a sack that one can move and put wherever they want, it becomes a more stable investment.
- Applicable where population density and scarcity of arable prevent traditional gardening.
- Conducive for contaminated soil is present.
- Best for places where there is a high chance of natural disasters such as floods or mudslides.
- Best in Where there is not enough ground-level sunlight to grow vegetables.
- Areas where drought is common or water very limited.
- In places where there is a food crisis. Small scale homestead vegetable growing can greatly alleviate pressure from relief efforts.
- Where there are community development initiatives and programs aiming to address community vulnerabilities.
- To complement school garden initiatives with non-traditional urban gardening techniques
Importance of sack farming
- It can be practiced in areas with high density like in urban centers, slum areas and schools.
- It accommodate high number of plants since 1 m3 space can provide up to 5m3 space for planting
- Applicable in areas with highly infected crops.
- Highly applicable in water scarce areas
Procedures of making the sack garden
- Select the best top soil from which is not affected by the soil borne diseases.
- From the selected top soil, mix with mature. Manure is highly recommended since it is organic and relatively cheap.
- Fill in the bag with the top soil enriched with the nutrients to the top.
- From the desired crop that may be tomatoes, onions, spinach, kale, and any other kitchen garden plant, you can either transplant the plants or the seeds into the bag.
- Sprinkle water to make the soil moist but not wet since very wet soils encourage fungal and bacterial diseases. But when water is being applied at large quantities; ensure the water draining system is incorporated in between the sacks to avoid the flooding.
4. VERTICAL CONE GARDEN SYSTEM
In this method of farming, the garden is made of concentric circles placed in a vertical manner in decreasing diameters.
These concentric circles are either made of hard plastic materials but can be manipulated to form circular shapes. The common plastic materials used are the dam liners and the greenhouse troughs or gutter.
The standard height are chosen to ensure good amount of soil is accommodated in the in these concentric circles.
The concentric circles are filled up to the top with the soil enriched with manure.
The support is provided for the concentric circles to minimize the falling of these concentric circles.
As the rule of thumb ensure the soil is not over watered. This is done to discourage the growth of fungal diseases.
5. NET FARMING SYSTEM
In net farming system, the plants are grown in a net closed structure of given dimensions. The net dimensions depend with the farmer’s budget and the type of the plant to be grown. The major plants grown in the net houses are herbs and the vegetables. These plants may include mints, thyme, berries, tomatoes, and passion fruits.
Importance of net farming
- High crop protection since nets do not allow the passage of pests that brings about crop diseases.
- Efficient use of irrigation water since the rate of evapotranspiration is reduced.
- Reduced rain off effects since the rain reaches the crops canopy in form of water shower.
- Reduced labor. One individual can manage a whole farm system.
- Weeds are highly managed.