Economical and ecological, drip irrigation is the solution of choice in the garden and even on a balcony. Coupled with a programmer, you will no longer have to worry about watering your plants so that they are beautiful and healthy!
What is drip irrigation?
- It is a low-pressure micro-irrigation system that starts with a simple water tap that feeds the main circuit consisting of a pressure reducer, a hose that carries the water to the plantations (diameter 16 to 25 mm), and then secondary circuits that can be made with thinner hoses (diameter 4 to 6 mm). The available hose lengths range from 5 to 100 m.
- Drip irrigation is usually coupled with a programmer that allows you to plan the watering times. The connected programmer offers even more freedom to the gardener.
- Note that there are watering kits that do not require a faucet or electricity. They are interesting in isolated areas or in the context of an unoccupied second home. They work from a rainwater collection tank, by gravity. The programmer is powered by batteries or even a small solar panel.
The dripper, the star of micro-irrigation
Watering each plant directly at its foot by drip is the goal of this micro-irrigation watering. To do this, drippers are placed on the pipes, with a fixed or adjustable flow rate, they allow you to irrigate each plant according to its needs by providing water progressively, drop after drop (from 0 to 20 liters per hour).
Note that the drippers can be placed directly on the first circuit if the watering plan is linear and/or on the secondary circuit.
From the simplest with a fixed flow rate to drippers whose flow rate can be adjusted by rotating the head, the choice is vast. The most fastidious will turn to professional solutions such as self-regulating drippers that compensate for a too low or too high pressure to deliver the required amount of water. These drippers will also solve the problem of a very sloping ground but be careful: often, they cannot be closed if a plant disappears unlike the adjustable drippers.
There are also built-in drippers for simplicity, but they do not allow the same creativity as a system where the gardener chooses to install his drippers according to the positioning of the plants already in place. Built-in drip lines have a spacing of 15, 30 or 50 cm, so it will be necessary that the garden is not yet planted or that the plants are exactly at these spacings for the system to be effective. However, this type of hose is easier to install and saves a lot of time.
What are the advantages of drip irrigation?
- This type of irrigation is very localized and ensures the preservation of water resources, the interest is both ecological and economic. Indeed, we count a saving of about 25 to 40% compared to a traditional watering for an efficiency 40 to 50% higher.
- The plants are watered at the right dose and in a regular way, which avoids the hydric shocks which weaken them in case of forgotten watering.
- The water is brought under low pressure to the feet of the plants and penetrates slowly towards the root system which benefits directly from it.
- The foliage is not watered, which avoids many cryptogamic diseases or leaf burns.
- The possibility of programming the watering offers a newfound freedom for the gardener who can finally go on vacation or take care of other activities.
How to install an efficient drip irrigation system?
Flow rate and pressure are the basic concepts of drip irrigation.
- Depending on the diameter of the hose, the flow rate will be more or less important. It is therefore crucial to calculate the necessary flow rate for the number of drippers installed and the length of the pipes.
- The flow rate of each dripper is given for a pressure of 1 bar (achievable thanks to the pressure reducer installed at the faucet outlet). For example, if you want to install 10 drippers with a flow rate of 2 l/h and 20 drippers with a flow rate of 4 l/h on your circuit you will need a total flow rate of 100 l/h. It is always better to limit yourself to a maximum of 50 drippers per circuit.
- A 16 mm diameter pipe will be chosen for a circuit of 50 to 100 m length, beyond that a 20 mm diameter pipe will be necessary so that the flow is always correct at the end of the circuit.
- Always differentiate between circuits with drippers and circuits with sprinklers. To do this, you can divide your irrigation plan into several circuits using directional elbows, bypass tees, plugs to complete a circuit...
- Don't forget to think about the solenoid valves needed to create several separate circuits. These solenoid valves, placed at the beginning of each circuit, are programmable. They work either under electrical tension via a programmer, or individually thanks to batteries. The solenoid valves allow you to operate each circuit independently.
- If your irrigation system has only one circuit, a timer will be installed just below the faucet to control the frequency, duration, and timing of watering automatically.
What is the best frequency to program a drip irrigation?
Watering should preferably be scheduled in the late evening after sunset so that evaporation is reduced and the plants get the most out of the water.
If each dripper corresponds to the real need of the plant, the watering can be started during one hour every evening in summer. In dry and hot weather, it can be extended by one hour. Only experimentation will help you decide on the duration and frequency, as each garden is exposed differently and exploited in different ways (presence or not of mulch, weeds...). It's up to you to learn how to dose, and to enjoy your tranquility!
