Technology to increase the yields of horticultural farms: Remote Sensing / Drones

New technologies based on Remote Sensing and Geographic Information Systems (GIS) have become very useful tools to manage horticultural crops more efficiently, with greater respect for natural resources.

Ángel Pérez, Food journalist

The digitization of the agri-food industry is one of the main priorities of the R&D&i policy in Europe for the coming years. Not only because it will have to feed an estimated world population of 9.5 billion people in 2050, but also because more advanced societies demand greater respect for the environment and natural resources.
Sustainability has become a permanent element in the information age, which opens a double aspect: the collection and management of data. The numerous technological advances that have emerged in recent times convert what we have historically known as the food chain into a process about which we have information at all times and at any point.
What we call Smart Farming, a global concept that represents an authentic revolution where control and data processing play a key role, has emerged. The results show the benefits it brings in terms of work scheduling, traceability, environmental impact or optimisation of resources, among many others.

More than half a century ago

With the help of Smart Farming, many completely new concepts have appeared for the agri-food sector. However, other aspects that seem new are not, as is the case of Remote Sensing, , of which there are scientific and technical references for more than half a century.

Experts define it broadly as the technique to obtain information about an object, area or phenomena on the earth’s surface, with methods that use electromagnetic energy, such as light, heat and radio waves.

Remote sensing usually uses sensors, on space satellites or other air or land vehicles, which capture images in various areas of the electromagnetic spectrum , which are visible, ultraviolet, infrared or microwave. The information obtained is recorded in the form of a digital image composed of pixels -small squares that usually have different colours- and is stored so that each land cover reflects sunlight to classify land uses or know what type of vegetation predominates.

Remote Sensing techniques make it possible to obtain, for each pixel, biophysical parameters or characteristics linked to the development of the crops, by means of relationships between the energy emitted by the crops -spectral reflectance- and said characteristics.

Among its many applications offered is farming, where information can be obtained about the vegetation without the need for direct contact. From an agronomic point of view, it is a tool for visualising, through images, the evolution and the differences in the appearance of the crop.

 

Application in horticulture

Its use in horticulture has grown substantially in recent times, in the interests of greater and better control of water and nutrients and, also, for early detection of pests, diseases and weeds. This is one of the most highly developed aspects, due to the interest it raises in the industry and the emergence of consultancy companies.

The current trend is to use Remote Sensing to obtain physiological information about crops with the energy the reflect at different wavelengths. For the horticultural sector, works related to the detection of cultivation patterns, deviations, estimation of force, leaf surface are also very useful. They facilitate inventories and counting of the plants and help to evaluate product quality for trade purposes.

It is all about fine-tuning tasks and performing what is strictly necessary with the maximum accuracy. In short, precision agriculture as a practice of agronomic management is based on measuring the variability of crops through application of Information Technologies, such as remote sensing by drones or satellites, global positioning data (GPS) or plant-climate-soil sensors, after incorporation into a Geographic Information System (GIS), analysing that variability and generating information to support decision-making.

Another advantage of Remote Sensing is its accessibility to different profiles, from large agricultural companies to small farmers, as they are affordable initial investments. From images originating from hyperspectral, multispectral, infrared or thermal cameras, information is obtained from different bands of the spectrum. They are used to obtain data that humans are unable to see at first sight and are processed to generate a series of agronomic recommendations to improve efficiency.

 

The expansion of drones

The agricultural farms begin to live a revolution starting from the new patterns established for the taking and management of the information that they offer and are capable of capturing and processing. Unmanned aerial vehicles – scientifically known as UAVs and popularly known as drones – have burst through many sectors, including agriculture, where they have originated, and are causing, remarkable changes in working methods and in the management and control of crops.

Before going into greater detail of agricultural applications, it is convenient to clarify the soup of acronyms that has arisen in parallel with this technology. It is true that in the end we tend to lump together and call any device capable of flying autonomously, regardless of its purpose, a drone. For the moment, and despite being in general use and familiar to all adults and children, the term is not included in the dictionary of the Royal Spanish Academy.

Then, more technically and precisely, there’s the UAV (Unmanned Aerial Vehicle), the UAS (Unmanned Aerial System – the aerial system plus the control system), the UCAV (Unmanned Combat Aerial Vehicle – Unmanned aerial vehicle capable of carrying armaments), the RPA (Remotely Piloted Aircraft – remotely controlled aircraft) and the RPAS (Remotely Piloted Aircraft System – remotely operated aerial system, in the case that the device and the control system are included). This final term is widely used in the European Union to refer to the devices for civil use.

Drones are here to stay and have caused some upheaval in different industrial sectors, although DJI , a world leading company in the sale of this type of equipment, predicts that 80% of the drone market will be absorbed by Agriculture – provided the law is changed and the sector is more regulated. The business seems clear and Spain is fourth in the world ranking of manufacturers, with more than 700 companies.

This boom has also caused authorities to have had to adapt the legal framework to the very varied benefits that these new tools are capable of offering. The Council of Ministers approved Royal Decree 1036/2017, of 15 December, which develops the Air Regulation and common operational provisions for air navigation services and procedures, in addition to approving the Air TrafficRegulation. That is to say, a new regulation that responds to the need to establish a broader legal framework that allows for development under safe conditions.

In parallel, professionals and companies specialised in design and manufacturing have emerged, which have adapted models used in other types of tasks to the agri-food sector.

One of them is ‘start-up’ Drone Hooper, which has evolved a model with a fairing design that makes it possible to combine a solid structure with wide payload capacity. It uses turbines distributed in motor groups that provide the power required for the flight and has a nebulizer control system to adjust to the needs of each operation. It was created to combat forest fires, but its benefits are also applicable to horticultural activities. According to the founder of the company, Pablo Flores, agriculture is “an opportunity and we have carried out tests on different types of crops, such as olives or and organic produce”.

One of the most widespread solutions offered by drones is the capture of aerial images from different angles at high resolution, at an affordable cost and at no risk for the farmer. Not only panoramic photographs, but also orthophotography, which is a presentation of a set of images of a specific area in which all elements have the same scale, free of errors and deformations. After the post-processing, and geometric image correction images, a high resolution orthogonal projection – without distortions – is obtained.

 

Trend

But technological progress never stops and merely making drones that are only capable of taking images and offering maps will become obsolete very soon.

At Hemav, a company created in Tarrasa by seven engineers from the Polytechnic of Catalonia which has become the fourth drone operator in the world and first in agriculture, they have gone a step further. “So far, we have only been concerned with obtaining information, and it was the farmers who eventually analysed it before making the decisions”, explains the CEO of the company, Xavier Silva. “The next phase is to move from colour maps to recommendation maps with estimates based on crop assessments.”

It is an agronomic work carried out with a specific software that helps to determine the vigour of the crop, to plan a selective harvest, to generate a map of nitrates or fertilisation, to determine water management or to detect diseases.

There is also a trend towards more robust drones, with greater flight autonomy in order to be able to carry out specific applications, such as selective fumigations or working plant by plant. “In Europe we are having great success in fruit and horticultural applications, especially in olive groves, vineyards, lettuce, tomatoes and beets, while in South America we work in soybeans and sugar cane,” says Silva.

In short, it is about saving costs for farmers by reducing irrigation water, fertilisers, phytosanitary products, as well as increasing crop productivity and optimising existing technology (tractors, machinery, etc.).