An automatic irrigation system can save time and provides concrete and practical irrigation, one of the most comfortable and productive for watering options, but to be helpful is very important to devote attention to your organization and design. In this article, we explain how to do it in detail.
Steps to be taken
- Draw a plan of the plant in your garden and copy it onto a grid sheet
- Select the diffusers and sprinklers taking into account the surface to be watered
- Measure the pressure and the available flow in your home
- Divide the irrigation system into several independent circuits
Material and tools you need
- blank sheet of paper
- a layer of graph paper
- measuring tape
- two measures
- marker pen
1. Draw your plot
- Take all the measurements of the areas you want to water.
- Sketch your garden, including the location of your house and the boundaries of the plot. Add all the details you can: sidewalks, patios, entrances …
- Indicate the areas you want to water and the ones that you do not. Pay attention to tall plants or other possible obstacles that may impede the correct distribution of water. Also, draw the parterres or areas that need different irrigation, such as areas with several pots that need a drip system.
- When you have completed the sketch, draw it with care and detail on a sheet of graph paper, respecting the measures you have taken as accurately as possible.
2. Choice of emitters: diffusers and sprinklers:
The issuers are chosen to take into account their reach and flow capabilities. To achieve uniform coverage, the scope of the emitters must overlap; that is, the same area must be spread over one another. The ideal distance between the transmitters is the radius of reach they have. This data is usually indicated in a table of characteristics included in the product.
Types of emitters
- Diffuser: its irrigation is fixed (although depending on the type of diffuser, the angle can be adjusted) and usually has a reduced or medium range. They are handy for watering areas with little space, such as corners or crops and small gardens.
- Sprinkler: they are designed to cover large spaces (their reach is usually between 7 and 20 meters), and their angle of irrigation is rotating, watering different areas.
Draw the irrigation area of each emitter: use a compass to mark the regions watered by the diffusers.
- Start by covering the corners with 90º emitters.
- Then cover the edges with 180º diffusers.
- If you have central areas without irrigation or with very little (the emitters do not overlap), you can complement them with 360º diffusers.
Taking into account the above indications, now pay attention to this example:
- Two zones (green and blue) that measure more than 5 m in diameter. In this case, the best option is to install sprinklers.
- One zone (red) that measures less than 5 m on each side. A diffuser system is the most recommended.
3. Measure the pressure and flow available in your home
The trouble is measured in kilograms per square centimeter (kg / cm²) or bars. You can measure it by placing a manometer in the water tap you want to use for irrigation. If you do not have a manometer, you can ask your water company for this information. Proper irrigation requires at least 2 kg / cm² (2 bars) of pressure. If your pressure is greater than 5 kg / cm2 (5 bars), you will need a pressure reducer.
The flow is measured in cubic meters per hour (m³ / h) and is indicated in the contract of the water company. However, we recommend you check it yourself: use the water tap closest to the meter to fill a 10L bucket with water and measure the time in seconds it takes to fill up.
4. Distribution and sectorization of the circuit
Unless you have a tiny garden, you may not have enough water flow to flood the entire space simultaneously. Therefore, it is essential and necessary to divide the irrigation system into several independent sectors.
Each sector must have its pipeline so that it can operate independently of the others. A solenoid valve and a programmer must control each of the circuits. You can manually control watering with cutting keys, but it is an unwise option.
Why are different circuits necessary?
Following this example, the water meter of the irrigation outlet only provides 3m³ / h, but to irrigate the whole area with the same circuit, 9m³ / h is needed. The solution is to divide the land to irrigate in three zones and each one has its circuit, which works through an electro valve (a product that opens and closes the passage of water through a pipe). The three electro valves will work successively, that is, one behind the other.
Now we show you the formula that you must apply to know in how many zones or sectors (with their independent circuits) you will need to divide the space to irrigate.
A number of sectors = total flow required / available flow in the housing.
You can calculate the total flow needed by knowing how much water each emitter needs and adding it. You will also find this information in the characteristics table that includes each product, as we have commented previously.
Above all, it is important that you do not mix sprinklers and diffusers in the same sector. They have different application speeds:
- Diffusers: from 7 to 8 min/day
- Sprinklers: from 20 to 30 min/day