SiAR, an application that allows the management of an irrigation program by calculating the water needs and irrigation dose for 104 varieties of crops, taking as evapotranspiration of reference the calculated through the data supplied by the network of stations

Source: Android description (translated)Android / Image: Pixabay

Useful information

Download: Android 3.0 (6.76MB) / iOS 8.1 (29.8MB) / web

Price: free

Language: Spanish

Runs offline: no (the application itself works, but the data are not displayed)

Last update: Android 06/10/2016 (v. 2.0) – iOS 06/10/2016 (v. 2.0)

Website of the developer: Mapama / Tragsatec


SIAR, an acronym for the Agroclimatic Information System for Irrigation, is an application developed by Tragsatec for the Ministry of Agriculture and Fisheries, Food and Environment (Mapama) which, taking as reference the data of temperature, humidity, speed and direction of the wind, solar radiation and precipitation from the network of agrometeorological stations, together with the calculation of evapotranspiration (through FAO-56), establishes the water needs of a crop. It should be noted, however, that this application is only valid in the autonomous communities included in the SIAR network, i.e. all except Basque Country, Asturias, Cantabria, La Rioja and Catalonia.

The operation of the application is as follows:

  • Once registered as a user (the query through the web requires of a different registration system), it is necessary to indicate on a map the plot of interest and the municipality where it is located. Based on these data, the nearest station is assigned, which will serve as reference (for this test a random vineyard plot has been selected in southern Navarre).
  • The next step is to select the type of crop. The application displays the most representative of the area, although you can also access the complete list.
  • Depending on the crop, you will have to complete different types of data such as date of planting (in the case of cereals, herbaceous or vegetables. The date should make reference to the current year) or data related to plot area and planting pattern (in the case of woody crops).
  • The steps 4 and 5 make necessary to choose the type of irrigation that the plot has (micro sprinkler, drip or surface) and the type of soil on which it is settled (sandy, frank, silty or clay)
  • The last requirement is the selection of the desired units, being able to customize the volume, the surface and the flow.

After executing all the previous steps, the application shows a summary sheet of the crop. The water requirement of the crop is calculated according to soil tilth, a term that can be defined as the «suitability for planting or growing a crop» and which is determine by «the formation and stability of aggregated soil particles, moisture content, degree of aeration, rate of water infiltration, and drainage» (Encyclopaedia Britannica online).

Once the crop is created, you can check your irrigation needs, its status (from this screen you can also configure the irrigation options), the meteorological data and the weather forecast, as well as edit the different variables selected along the previous steps or delete it.

More information

Agricultural/forestry applications and climate services in Spain (*.pdf, 2.14MB)

Images: Screenshots 21/11/2016. ©Mapama/Tragsatec



Agriculture is the main consumer of water. As the European Environment Agency confirmed in 2012, «a third of water use in Europe goes to the agricultural sector». Therefore, it is necessary to implement measures aimed at maximizing the efficiency of agricultural irrigation, more in a country such as Spain, where to the historical scarcity of water, capricious geography and meteorology and infrastructures that waste a quarter of the water supplied, it will be added a more than foreseeable worsening of the problems as a result of climate change. Not in vain, a 2015 study of the World Resources Institute placed Spain as one of the countries that will have the most water problems in 2040.

The SIAR app was designed just as an instrument to allow a more efficient use of water. What is interesting about the application is that it is not only valid for cultivated fields, but also, by including different varieties of grass, it could be useful for managers of sports areas. Although the application is easy to manage, there are some aspects, such as the choice of municipality, whose purpose is not very clear. Similarly, perhaps it would be interesting to see a map with the location of the stations and their status, since there may be some that do not work, as you can see in the SIAR of Castilla La Mancha.

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Técnico de medio ambiente, community manager y content curator especializada en temas de medioambiente - Environmental technician, community manager and content curator specialised in environmental issues