Drones are becoming increasingly important in many areas of agriculture, not only in arable crops but also fruit production and viticulture. In Sicily, the company Pheromed Fly, which has offered drone services since 2015, has seen significant growth in requests from farms that have decided to use these tools as a support for agronomic management.
“Up until a few years ago we were only working with farms on an an experimental level” explains owner Giovanni Petriliggieri. “Today, we have fully entered the agricultural sector, which comprises about 30% of our business.” Mr Petriliggieri has dedicated himself to research, working with institutes and universities to test the usefulness of surveilling crops using these tools, in comparison with traditional visual checks performed by agricultural technicians.
The advantage of flying
“It is much less effective to check crops on the ground plant by plant, compared to from the air, which provides a much wider and more comprehensive view,” he says. “And above all, it allows the use of high-precision detection tools.” The drones used at the farm are more than a meter across, and come equipped with multispectral and digital cameras which collect high definition images in flight, above 45 Mpx, to obtain precise and complete plot mapping.
“The use of multispectral cameras, which have five different colour bands, allows to calculate the vegetation indices based on the percentage of radiation reflected in the various specific bands.” The most common vegetation index, Normalised Difference Vegetation Index (NDVI), evaluates the presence of photosynthetic activity, comparing the red spectrum, in which the chlorophyll is absorbed, with the nearby infrared spectrum, in which the leaves reflect light to prevent overheating.
“Living in Sicily, we started with citrus trees, which represent our largest crop,” continues Mr Petriliggieri. “With the University we undertook various experiments in different areas of Italy on vines, pomegranate, kiwi, and fruit trees, as well as wheat and rice. The data collected is always georeferenced, it is the interpretation that changes.
Monitoring from the air is much more efficient than monitoring from the ground, where each individual plant is checked.
Once all the data has been collected by the drone, it must be interpreted. Only then can corrective measures be taken. This is done by the farm’s agronomist who, based on personal experience, makes the best decisions to return the crop to its optimal condition. “The use of the drone makes additional functions possible, like being able to photograph the farm from above, obtaining precise mapping of the fields.” This allows important decision-making information to be gathered prior to preparing irrigation systems, pruning or simply to help understand the productive potential of the ground.
A perfectly controlled orange grove
Another farm that is using drones as a strategic business tool is Bioagricola F.lli Solarino in Rosolini, in the province of Syracuse. Here, the 30ha of organic orange groves have been constantly monitored since 2017 using drone mapping. The farm’s most important crops are various varieties of yellow pulp oranges, which are exported all over Europe.
The evolution of technology helps us to avoid the use of pesticides.
“Our farm can be considered an organic pioneer,” explains CEO Monica Solarino. “We started in 1996 when there was still a lot of scepticism about this type of farming, but we believed in it and gradually made full use of all the possibilities offered by the evolution of technology to avoid the use of pesticides.”
The orange groves are perfectly kept. The plantings are never more than 30 years old and are renewed regularly to be strong, healthy, productive plants. The genetic variety has been increasingly evolved to cope with climatic stress in an organic system. During the hottest and driest months, irrigation is used with underground systems that not only save water, but also reduce the presence of surface weeds, reducing the need for of mechanical weeding.
What made it possible for the farm to make a real qualitative leap was the use of drones for crop monitoring. Since then, Bioagricola F.lli Solarino has increased production by at least 20%, reduced waste, and above all, has significantly improved the quality of the oranges it produces.
Between flowering and harvesting
“In the experimental phase we performed two flights a month,” says Ms Solarino. “Today we program four to five flights between flowering and harvesting. This makes it possible for us to keep the vegetation and development index of the plants monitored, pointing out if and where there are problems or failed areas”.
“When mapping shows areas that are turning yellow, this means that the plant has problems,” she explains. “Based on geolocalisation, the technician can go and see what the problems is. Sometimes there are plant protection problems, other times there are problems with irrigation or fertigation systems. In either case, this technology has made it possible to improve and significantly reduce the use of technical resources.”
Thanks to the drones we can estimate the production in advance and better organise the harvest, grading, packaging and shipping.
Another benefit of using the drone is the capability to estimate production in advance, using the multispectral camera to see the amount of fruit per hectare as soon as the colour starts changing. “Knowing the plant yield in advance is extremely important for us, as we can better organise the harvest and all following phases of grading, packaging and shipping.”
“Today, the cost for using a drone service is perfectly sustainable, says Ms Solarino. The advantages far outweigh the costs, which generally never exceed €30-40/ha (£26-£35) – savings are made in products, irrigation and labour. In addition, the drone used at this farm has provided an indispensable service, from the design and calibration of the subirrigation system based on individual field terrain, through to deciding whether to replace the orange plantings”.
“Thanks to drone mapping, we can choose the right moment to replace plantings and make important choices in extraordinary situations, like the recent Citrus Tristeza virus attack. Only multispectral aerial monitoring is capable of following the evolution of such an attack, simultaneously indicating the right path to follow.”