Intended for agricultural researchers and stakeholders, “Aquacrop” is a crop water productivity model developed and distributed by FAO since 2009. by evaluating different parameters, it enables yields to be improved in an environment where water is scarce. A robust model that is easy to use and produces rapid results whose usefulness increases in line with the scope of challenges related to global changes.
A simple and robust model
Developed by a team of physiologists and engineers, the Aquacrop model is an intuitive and easy-to-use tool that extension workers can use to achieve optimum efficiency. The data required by the model are simple and need no complex calculations. This includes details of the crop, the climate, the condition of the soil, management and yield, etc. Once the data have been entered into the Aquacrop system, a calculation (highly complex) is automatically performed, and the results are almost instant: at that point, information is provided on how and when to irrigate corn to get the best yield, etc. A computer is all you need to use the model, which is available as a free download from the FAO website. The model can be used anywhere in the world, for any type of crop; for example, beans, sugar beet, etc. A large number of crops are modelised and calibrated in the model, but Aquacrop allows the data to be very finely contextualised. Dirk Raes, one of the main developers of the Aquacrop model, a researcher and teacher at the Division of Soil and Water Management at the KU Leuven University (Belgium), explains the richness of the model in the case of corn in this way: “Aquacrop includes a ‘general’ model for corn that incorporates the generic characteristics of this plant (sensitivity to drought, soil salinity, etc.). However, the model also includes questions to refine the analysis
(Is it a long-cycle or short-cycle corn? When was it planted? In what density? etc.).”
Training, at the heart of the development of Aquacrop
Aquacrop’s promoters are not content simply to distribute it without support for users. Particular attention is therefore given to training. Workshops are held worldwide (in English, French, Spanish, and even in Russian) through the intermediary of FAO. Dirk Raes has led a number of these courses, in China, Egypt, South Africa, Burkina Faso, etc. The five-day training courses and workshops for thirty people combine theory and practice. On completion of the workshop, the participants are able to use Aquacrop independently. These workshops also provide FAO with the opportunity to test its model, which is constantly being adapted in order to make any necessary improvements. The software is currently in English. There is a user manual in French, and translations into the official languages of FAO are planned (as well as French and English, there will be Spanish, Chinese and Arabic).
Success and limitations of the model
The success of the model is undeniable. This is unanimously agreed in the world of research, as evidenced by the numerous scientific publications in which it features annually. As further proof, the Aquacrop website is extremely popular (1,200 visits per month to the Aquacrop page, according to recent estimates). Nevertheless, Dirk Raes wonders if the original target of the extension workers and agricultural development agents has been reached: to date, FAO has received little feedback on the use of the model and its real impact from these key stakeholders.
Furthermore, the researcher, who is focused on constantly improving the model, also sees its limitations: “We may well have a wealth of data, from which we make detailed analyses and recommendations, but Aquacrop does not make the policies. The next step is the creation of a model that goes even further, new software that translates the results into practical advice that is even more precise.” ◀
Dirk Raes is a researcher and teacher at the Division of Soil and Water Management at the KU Leuven University, Belgium.