- When to water?
- From micro-irrigation to drip
- Manage the distribution of water
- Recycle water to save
- Know the nature of the soil in your garden
- Program watering
- Distribute the irrigation circuits
- Water according to the weather
- Use a pump
- Collect rain water
- Irrigation systems for medium and large areas
- Small area sprinkler systems
- The opinion of the expert on methods of watering
Watering is essential to have a garden in good health. But to avoid seeing its consumption of water and therefore its bill explode, it is necessary to water intelligently. Explanations...
Climate, type of vegetation, nature of the soil, orientation of the garden... are all factors to understand before choosing a watering technique. It is also necessary to take into account the periods of strong heat or windy which accelerate the process of evaporation.
When to water?
In springAs the soil starts to warm up but the nights are still cool, water intake is preferable in the morning to keep soil moisture as long as possible.
In summer, do not water in direct sunlight, as up to 50% of water evaporates before entering the ground. Better to privilege watering in the evening or very early in the morning and average 5 to 7 mm of water a day. But these values can only be indicative because everything depends on the nature of the soil, the climate, the exposure of the ground.
However, to maintain a lawn and promote its rooting, it is better to opt for a copious watering once or twice a week rather than low daily water supplies.
Finally, according to the saying: a hoe is equivalent to two waterings. Biner consists of loosening the soil by breaking the earth's surface crust about two centimeters. This increases the permeability of the soil, reduces the presence of competing vegetation and decreases evaporation. The manual method with the watering can is essential to the feet of the massifs and for flowerpots in suspension, on a terrace or a balcony. This local watering limits the loss of water and helps to dose correctly. It is carried out at the foot of plants (technique of the bowl) or the apple for planting in the kitchen garden. More restrictive, it requires several trips / returns to the point of drawing (tap, recuperator).
From micro-irrigation to drip
Watering the pipe limits these movements. Associated with a multi-jet gun, it allows to water differently according to the plants. Sprinkling uses retractable devices with fixed or rotary jet (nozzle, sprinkler, gun...) which project water in height to reproduce the effect of the rain. The micro-irrigation, by diffusion or by drip, conveys the water of localized way with the foot of the vegetable with a low flow (porous pipes, drippers, micro-sprinkler) for the water supply near the roots, without loss and with low consumption.
Another method that is developing is the sub-irrigation. It ensures the water supply of young trees, at their roots, by buried porous pipes. The pressure is low (1 bar) and the flow is very low (1 l / m). Essential to properly power a network that includes different watering systems (sprinkler, dripper, nozzle...) more or less greedy water, the pressure affects the flow of water and requires to adapt the diameter of the supply pipes.
To know precisely the pressure delivered (generally 3 bars, but we can find in some regions lower flow rates), it is necessary to estimate the flow of water per hour. To calculate it, simply open the garden faucet as much as possible and count the time needed to fill a bucket with water. The bucket full, the capacity (example: 10 liters) is multiplied by 3,600 (one hour consisting of 3,600 seconds), then the result obtained is divided by the number of seconds necessary to fill the bucket (18 seconds for example). Here, the maximum water flow is 1,200 l / h, that is: (10 x 3600) / 18 = 1200 l / h.
Manage the distribution of water
Depending on the surface, it may be wise to multiply the points of draw to supply water to the various plants present in the garden. As the irrigation equipment is different and does not solicit the same water flow, the distribution can be separated to water the lawn, the kitchen garden or the massifs.
If a garden faucet is installed on one of the walls of the house, it can supply several hoses. For a distance of less than 10 m, a compact pipe is sufficient (retractable or expandable model), while for a distance greater than 20 m, a wall feeder near the faucet facilitates handling and storage. Beyond 40 m, it is useful to dig a trench (about 1 m deep) and bury a pipe placed on a bed of sand (semi-rigid polyethylene pipe with an outside diameter of about 20 or 25 mm) connected directly to the main water inlet. At its end, a valve accessible from a glance embedded in the ground makes it possible to connect there any kind of watering systems.
Recycle water to save
Some domestic sewage can be reused safely to water the plants. For example, you can use rinsing water for vegetables and salad or cooking water for vegetables (except for potatoes that are toxic) and eggs (high in nutrients).
It should also be noted that the aquariums drain water is rich in organic waste and that the defrosting water of the refrigerator is a fresh water perfect for vaporizing the plants.
Know the nature of the soil in your garden
There are mainly three soil types in France. Clay soils, so-called heavy, conserve water very well. They are not draining and dry slowly. Sandy soils, said to be light, are on the contrary very permeable. They dry quickly. The loam is between the two. They hold water well and are perfect for planting. Of course, soils are never totally sandy, loamy or clayey but contain varying proportions of these three types of soil. They can be supplemented by limestone (whitish alkaline earth) or humus (dark colored acid earth with remains of plant debris). To get an idea of the type of soil on the ground, it is sufficient to examine the existing flora on the ground (for example, thistles and sow thistle in heavy soil, or field thoughts or anthemis in light soil).
A modest network is satisfied with a programmer with batteries (or solar collectors) connected to the tap. Equipped with preset programs, it allows to select the duration, and sometimes the start time and frequency of watering. To manage several circuits, a programmer must be able to independently control the solenoid valves required for the hours recorded. Depending on the model, order transmission is carried out by very low voltage, infrared or radiofrequency cables. It proposes multiple departures and several independent programs adaptable to the needs of the areas to be irrigated. It is often associated with a hydrometric probe and an electronic rain gauge.
Distribute the irrigation circuits
Connected to an external tap, a multi-circuit selector facilitates the distribution of water in the various sectors of the garden by allowing to connect several hoses. It is also possible to install a timer and even fill a watering can.
Water according to the weather
In addition to a rain gauge, the weather sensor measures the temperature, the brightness and the moisture content at the root of the plants. The information is transmitted on tablet or smartphone via a dedicated application.
Use a pump
Immersed in a well or connected to a rainwater collector, a pump delivers the pressure necessary to water the turf by retractable sprinklers or to connect a lance or a spray gun via a pipe.
Collect rain water
Simple and quick to install, a collector is an effective solution to collect rainwater from a gutter downhill. Once the tank is full, the rainwater automatically joins the sanitation network or the specific network (excluding the domestic network supplying the house). On some models, it is even possible to connect multiple collectors to increase the storage capacity.
Irrigation systems for medium and large areas
Static watering systemComposition of the garden : flower beds, flower beds
Setting up: to bite into the ground or to lay on the ground
Area: <70 m²
Pressure required: <1 bar
Consumption: About 40 l / h / m²
Rotating watering systemComposition of the garden: Lawn, massive...
Setting up: to plant or to place on the ground (or on a tripod)
Area: from 50 to 300 m²
Pressure required: 1.5 bar
Consumption approximately 12 l / h / m²
Oscillating watering systemComposition of the garden: lawn, vegetable gardens, structured gardens with massive
Setting up: to be placed on the floor or on a tripod
Area: from 70 to over 700 m²
Pressure required 2 bars
Consumption: 15 to 20 l / h / m²
Cannon watering systemComposition of the garden: large lawn, shrubs
Setting up : to be placed on the floor or on a tripod
Area: Up to 700 m²
Pressure required : 3/4 bars
Consumption: 20 to 70 l / h / m²
Small area sprinkler systems
Nozzle watering systemComposition of the garden: small lawn, shrubs, flower beds
Setting up: buried in the ground
Area: from 0.6 to 5.5 m² / nozzle / angle
Pressure required: from 1 to 2.1 bars
Consumption: 0.05 to 1.2 m³ / h
Micro-sprinkler irrigation systemComposition of the garden: kitchen garden, "greedy" plant in water
Setting up: on the surface near the planting foot
Area: 0.5 to 2 m
Pressure required: 1 to 2 bars
Consumption: up to 120 l / h
Drip irrigation systemComposition of the garden: vegetable garden, shrub, planter, potted plant
Setting up: in surface at the foot of plantation
Pressure required: 1.5 bar
Consumption : 2 to 4 l / h
Microporous hose irrigation systemComposition of the garden: kitchen garden, borders, hedges
Setting up: on the surface or buried at the foot of the plantation
Area : localized
Pressure required: 0.2 to 0.8 bar
Consumption: 1 to 8 l / m
The opinion of the expert on methods of watering
"The watering behavior is very different between a sprinkler and a drip The sprinkler must penetrate the water up to 30 cm deep (which corresponds to 30 or 40 mm of water) in order to have four to five days of useful reserve, the drip must, on the other hand, maintain a pocket of water in the soil, which leads to the opening of the drip for ten minutes, twice a day ".
* Jean-Pierre Estivals, agronomist, teacher at the agricultural school of Albi-Fonlabour (81).