Estimating Crop Water Needs Using Unmanned Aerial Vehicles

In collaboration with the University of California (and thanks to an invitation from the Vice-President of such university for a project led by Dr. David Goldhamer) will be conducting flights over experimental plots with different crops, some of them being the largest pistachio nut crop in the world, as well as over almond tree and vineyard crops spread across the State of California. This system allows you to know the ideal time to water the crops, saving water, and it can even be used to detect situations of water waste or water leaks in the irrigation system. The method has been used in more than 600 flights made between 2007 and 2009 in wheat, corn, peach, olive, orange and vineyards fields in Spain.

In this case it is not only a case of cooperation in the scientific field. According to Pablo J. Zarco-Tejada, one of the participating researchers, ‘is a work also related to private companies (through the program of research result transfer of the University of California to agriculture companies). The companies interested in this technology are AgriWorld and Paramount, the two largest pistachio and almond producers in the world'.

The system is based in small unmanned planes which can fly between 50 minutes and 2 hours and explore up to 1,000 hectares at an altitude of 300 m. above the ground. ‘The planes are equipped with a GPS system that continuously informs of its location to a base station from which the platform is operated and its mapping is observed' Dr. Zarco‑Tejada explains, a researcher of the CSIC leading the project of Cordoba Institute for Sustainable Agriculture (IAS).

'Moreover the aerial robot flying plan can be updated in real time' J.A. Berni said, researcher who has Developer the UAV remote detection integrated system. Planes, which fly above crop fields at an altitude of 150 to 1000 m., are equipped with a thermal camera and a multispectral one. The former delivers the temperature of the surface vegetation and after a series of calculations based on crop transpiration models, it detects water stress vegetation.

The most advanced available system

'There are unmanned aerial vehicles in some countries, mainly in the military sector. In civil applications we can say that our unmanned platform, together with the multispectral and thermal cameras for remote detection, is the advanced one in the market now, fully equipped and fully operative', Professor Zarco-Tejada added.

The idea of these new systems is part of the project on controlled deficit irrigation called CONSOLIDER-RIDECO, led by Professor Elías Fereres Castiel in which researchers from all over Spain are working. Fereres, through the University of Cordoba and the Sustainable Agriculture group of the CSIC, has been collaborating for over 20 years with the University of California at a scientific level.

The international participation of this type of groups specialised in unmanned aerial robots for studies on water needs is scarce. This is what precisely makes this Project particularly interesting for several companies and bodies in and outside Spain', ‘specially for countries or areas with Mediterranean climate where water is scarce'.