A typical drip irrigation system has some components. These components work together for the drip irrigation system to do its work. Drip irrigation is a trickle form of irrigation; it passes water to the root zone of plants in droplet or trickle manner. Drip irrigation is known to be one of the most efficient types of irrigation in the world.
The following are the components of a typical drip irrigation system:
Drip Tapes: The drip tapes are the main components of the drip irrigation system. These are light polythene pipes that are set on the surface of the soil. The drip tapes usually have emitters pre-installed on them by the manufacturers. The emitters are installed at specified intervals say 20cm, 30cm, 50cm or 60cm.
Drip tapes come in different thickness. Some drip tapes are 02.0mm thick, some 0.230mm thick and some 0.50mm thick. The drip tapes also come in rolls of 500 metres, 1,000 metres, 1,500 metres and 2,000 metres.
Valves: Valves are the components of a drip irrigation system that stops or open the flow of water in the tubings or pipes. With valves, a farmer can stop the flow of water to a section of his drip irrigation system; he can also direct the flow of water to a section of his drip irrigation system.
Valves are common; they are used in building plumbing work. As it works in building pipes, so it works in the drip irrigation system. Some of the types of valves used in drip irrigation are web-enabled valves, control valves and isolation valves. The web-enabled valves are controlled by the internet; a farmer can be on his bed and use the internet to control the web-enabled valves.
The isolation valves are used to isolate a section or zone of the drip irrigated farmland. The zone can be blocked from receiving water for a period of time with the help of the isolation valves. The isolation valves can also be used to block the whole drip irrigated farmland from receiving water.
Backflow Valve: This is also called backflow preventer; the backflow valve prevents water from going back to the source of water. It makes it possible to avoid the flow back of chemicals, dirts, fertilisers and other unwanted substances to the source of water. Imagine, you fertigate with your drip irrigation system, if you do not have a backflow preventer, the fertigated fertilisers can flow back to your source of water. This can poison anyone that drinks the water later.
Pressure Regulators: Imagine, you bought a drip irrigation system that can only work with 1 bar pressure and your water pump pumps water at 5 bars, what will you do? If you install the drip irrigation system and you pump water directly into it without using a pressure regulator, the drip irrigation will get damaged. As a matter of fact, the drip tapes will get torn.
Pressure regulators adjust the water pressure of your water pumping or flow system. Some pressure regulators are adjustable; you can adjust it to the pressure level you want. Some pressure regulators can also automatically adjust themselves.
A lot of pressure regulators around are pressure reducing regulators. A pressure reducing valve can also act as a pressure regulator in a drip irrigation system.
Most pressure regulators in Nigeria are made of plastic or brass. The plastic pressure regulator is the commonest type of pressure regulator in Nigeria.
Filter: Do you wonder why your drip irrigation tapes or tubes get blocked frequently? Have you seen farmers abandoning their drip irrigation systems because the emitters stop dripping water? The cause of these problems is likely to be non-availability of filter on the drip irrigation system. It is advisable to use filters on your drip irrigation systems if your water is not clean or if your water has particles and impurities.
A filter is a small equipment used in filtering the water passing through the drip irrigation pipes. The filter ensures that no impurities or particles go into the drip irrigation system. The filter is usually installed on the main line of the drip irrigation system.
Filters come in various sizes, there are filters with 120 mesh size, some with 150 mesh size. You need to buy the one that best suits your drip irrigation system.
Emitters: The emitters are the small devices on drip tapes or drip tubes that emit water in droplet form on the root zone of plants. The emitters used in drip irrigation are used in the passing of water, nutrients and chemicals etc. to the roots of plants. Without emitters, the drip irrigation system is useless.
Some drip emitters are pre-installed on the drip tubes; this is common on drip tapes. These pre-installed emitters emit 1-4 litres of water per hour. There are also emitters that are removable; this type of emitters can be installed at fixed intervals on the drip tubes. The removable emitters can emit 5-70 litres of water per hour; the water flow capacity can also be adjusted.
Mainline: The main pipe that brings water from the water source to where the control valves are located is called the mainline. The mainline is normally a PVC pipe. In Nigeria, the PVC pipe is commonly used by small holder farmers as mainlines. However, HDPE and LDPE pipes can also be used as mainlines especially if the source of water is from dams or rivers.
The mainline is normally much thicker than the drip tapes because the water pressure it will tolerate is expected to be higher than drip tapes’. It is not uncommon to see mainlines lasting for 10-20 years.
Laterals: The laterals also called sub-mains are the pipes between the control valves and the drip tapes. In Nigeria, the sub-mains are usually the lay flat hoses the drip tapes connect to. The sub mains are usually inserted with croco connectors, with the croco connectors, the drip tapes are well connected to the sub mains or the laterals.
In Nigeria, it is advisable to buy lay flat hoses that are UV tolerant and also re-inforced. Most of the lay flat hoses in Nigeria are sub-standard but cheap, you need to be extra careful when buying drip irrigation components because they appear cheap.
Lay Flat Hose Connectors: These are also called croco connectors. They are used to connect the drip tapes or pipes to the lay flat hose or sub main pipe. The punch toll is used to perforate holes in the lay flat hose so that the croco connector can be inserted.
Venturi Injector: This is the equipment used for fertigation and chemigation. It is used for the injection of fertilisers and chemicals into the drip irrigation system. With a venture injector, fertilisers like NPK, urea, calcium nitrate, chelate, mono potassium phosphate and calmag etc can be passed to the roots of the plants. The venturi injector makes fertilization cost effective for farmers.
Other components of a typical drip irrigation system include grommets, take offs, air valve, and end plugs or stoppers etc.
Read our article on how to design a drip irrigation system.