Micro-irrigation is an effective water-saving technique that offers a solution of choice for both gardeners and agricultural companies. With an incomparable efficiency, this system allows to water the plants at the right time and at the right dose.
What is micro-irrigation?
Developed in the early sixties, micro-irrigation ensures optimal distribution of water under low pressure directly to the feet of the plants concerned. Of course, already in ancient times, the issue had been addressed by the use of oyas, these porous buried jars that ensured effective watering close to the roots.
But let's go back to the current system which has the advantage of being able to be planned by cycles, according to the climatic conditions, and which allows to choose the flow intended for each plant.
Otherwise known as 'localized irrigation', this technology was created in Israel in 1959, when the advent of plastic pipes allowed its development. Patented in 1960, drip irrigation quickly took off in America and Australia. Nowadays, this system is recommended in arid countries and in hot climates. Unlike conventional irrigation, which waters the entire soil indiscriminately using maximum pressure, micro-irrigation provides water in a punctual manner, on a well-defined area of the soil and at low pressure.
What does a micro-irrigation system look like?
There are several micro-irrigation media, although drip irrigation is the best known and most widely used, especially by individuals.
- The drippers work under a pressure of 1 bar. Each dripper is fixed independently on the whole length of a pipe of 0,5 to 1,5 mm of diameter. With one or more holes for water flow, the dripper can be chosen or adjusted (depending on the model) to the right flow rate for each plant (from 0 to 20 l/h).
- Micro-sprinklers, micro-diffusers or micro-sprayers are generally used in arboriculture. They can be fixed on a stake and diffuse water on 40 cm by rotation of the cap with an adjustable flow from 0 to 60 l/h.
- Micro-porous pipes are perforated with a multitude of small holes from which the water flows at low pressure along the whole length.
Advantages of micro-irrigation
This controlled watering technique allows enormous water savings (25 to 40%) compared to flood or runoff irrigation techniques with an efficiency 40% higher.
- Micro-irrigation can be coupled with a programmer, or even a weather station or an application to manage the watering according to the real needs corresponding to the climatic conditions. You can even be notified in case of water shortage or technical problem.
- Evaporation is less, especially when the system is activated at the end of the day. It also helps avoid many cryptogamic diseases that spread through the watering of foliage.
- The hydric shocks so harmful to plants are avoided. Plants not stressed by the lack of water are more vigorous and less sensitive to parasites.
- In a large farm, it allows to reduce labor costs.
- The rooting of the plants is favored by this system.
- There are far fewer weeds, which avoids competition for cultivated plants and tedious and time-consuming weeding.
- This technique allows for the direct addition of fertilizer during watering in large-scale agricultural operations.
- Knowing that the water consumption of intensive agriculture corresponds to nearly 70% of the world consumption, that water resources are beginning to decline or even disappear in some areas, the problem of food security may become burdensome. Micro-irrigation helps to overcome this problem.
Disadvantages of micro-irrigation
Although few in number, there are some disadvantages to installing a micro-irrigation system.
- The cost can be prohibitive when it comes to irrigating a large plot of land. However, at the level of a medium-sized private garden (500 m²) or even better, a simple balcony or terrace, it is possible to obtain very affordable kits that will quickly pay for themselves.
- Another concern is the technical nature of the installation (calculation of pressure losses, installation of the pressure reducer, knowledge of the right pipe diameters, creation of the different circuits, adjustment of the flow rate of the drippers and their number, installation and adjustment of a possible programmer...) which can frighten the novice gardener or those who are not very handy.
- The drip system should be checked often enough because some drippers can be clogged, especially by ants or soil debris.
- Leaks and breaks are not impossible, especially after the brushcutter has been used! If you don't do your own brush cutting or mowing, always remember to tell the person in charge of this work that an automatic watering system is in place, otherwise your garden will be compared to the water games in Versailles as soon as the watering system is turned on!
