Unmanned aircraft, also known as drones in the military, are the result of aerospace technology that has relatively recently had a civil development and been sent to fields to revolutionize precision farming in the 21st century. These small aircraft, equipped with special cameras, are able to take remote images with great detail, allowing farmers to have maps that reveal the state of their crops: water and nutritional needs and the location of diseases.
The images allow farmers to see what their eyes can't, which is possible thanks to detectors that capture radiation outside the visible spectrum, said Pablo Zarco, director of the Institute of Sustainable Agriculture (IAS) of the National Research Centre ( CSIC ).
Zarco explained that, "by analyzing and processing the radiation that these cameras capture we generate maps of what the farmers are really interested in," so, for example, the red areas indicate an absence of water and the blue areas where the water status is OK.
"These aircraft allow farmers to easily have a series of data at their fingertips, as if they had a satellite at their disposal, but at a much lower cost and with a greater precision," according to Antidio Viguria the head of the area of unmanned systems of the Advanced Aerospace Technologies Central (CATEC).
This is also demonstrated by the system developed by the team of the IAS- CSIC researcher Francisca López-Granados, which uses drones to map the crops and detect the areas where herbicides must be sprayed. As the maps are georeferenced, the area where treatment is necessary is narrowed down and it's not necessary to apply the herbicides throughout the entire plantation, as the researcher estimated that 70 % of the fields don't require it. "Widely applying pesticides regardless of the location of infestations imposes costs and unnecessary environmental impact," notes Francisca López-Granados.
They all agree that these maps contain a large amount of information that must be processed by an expert. "The image itself is nothing" sums Viguria, because the result is a "mosaic, a map of the field's temperature from which a scientist calculates parameters used to suggest where to use fertilizers, phytosanitary treatment or add irrigation systems.
CATEC and CSIC, from Spain, participate together with partners from Belgium and the Netherlands in the community project FieldCopter that developed this system of collecting information through multispectral cameras equipped on these drones, which weigh between 5 and 25 kilos. The project is still in its test phase, in the final phase, but it is already showing its effectiveness.
The experiments have been conducted on potato fields in Belgium and the Netherlands, as well as in vineyards in Spain, where the prototype has been tested with excellent results and a clear advantage over satellite images, with an accuracy of 3 to 10 centimetres per pixel, compared to the meters accuracy given by satellites.
Another advantage is that, in the case of a satellite, the farmer has to wait until its orbit passes above his farm to be able to take data (once every three days) and, if it is cloudy, they can't take a multispectral photo but they still have to pay for the service.
Thus, "the applications of this technology in agriculture are enormous," assures Lopez-Granados, who has had more than 15 years work experience in precision agriculture, and who predicts a this technology will be greatly used in agriculture, forestry or mining.
In fact, estimates are that this vehicle's two main applications in the next decade of these will be to perform in the field of earth observation and security. "90% of the market will be divided into agriculture and security," notes Zarco, "the goal in agriculture is to develop smaller platforms that are easy to use, which would give us information about the state of the crops in a minute at a very low price."
The idea is to offer this model as a service to the farmer or entrepreneurs, rather than having them acquire the system, since it is a complex technological equipment that needs a specialized team to interpret its data.
The real revolution, emphasizes Zarco, "isn't that there are unmanned planes flying alone but that they have miniaturized sensors and cameras, which allow farmers to continuously take operating decisions."