For some, drones still conjure images of death and destruction – that has been their most widely reported use. But that reality is fast changing. Unmanned aerial vehicles (UAVs) are being used for many peaceful purposes, from newsgathering and post-disaster assessments to goods delivery and smart farming. Drones come in various shapes and sizes: as miniature fixed-wing airplanes or, more commonly, quadcopters and other multi-blade small helicopters. All types are getting simpler, cheaper and more versatile.
Unlike radio-controlled model aircraft, which aviation hobbyists have used for decades, UAVs are equipped with an autopilot using GPS and a camera controlled by the autopilot. These battery-operated flying machines can be manually controlled or pre-programmed for an entire, low altitude flight.
In 2014, MIT Technology Review listed drones among its 10 breakthrough technologies of the year. In particular, it identified the use of drones in farming and natural resource management that benefit from having a bird’s eye view (hitherto possible only by using a manned aircraft or satellite images, both expensive options).
“The advent of drones this small, cheap and easy to use is due largely to remarkable advances in technology: tiny MEMS sensors (accelerometers, gyros, magnetometers and often pressure sensors), small GPS modules, incredibly powerful processors and a range of digital radios. All those components are now getting better and cheaper at an unprecedented rate, thanks to their use in smartphones and the extraordinary economies of scale of that industry,” it noted.
Data-driven farming
Mechanising farming goes back to the 1950s, when tractors and other gadgets began to be promoted under the Green Revolution. However, some who were at the forefront of that wave later questioned its wisdom.
Ray Wijewardene – the inventor of the hand tractor for small farmers – pointed out how the drive to boost yields increased farmers’ input costs, thus reducing their profit margins. It also led to unintended consequences of agricultural runoff that caused environmental and health problems.
So new tech tools coming to farmers’ aid should be scrutinised for their costs and benefits. One new trend is the move towards data-driven farming with the help of drones.
Also known as Precision Agriculture (PA) or smart farming, this management concept is based on observing, measuring and responding to changing conditions in the field. In this, information technology combines with farm mechanisation to provide farmers with scientifically gathered data to optimise the use of water, fertilizer and other agrochemicals.
Contrast this with many approximations and guesswork that farmers currently use in tending to their crops. Some do have intuition, but in these times of unpredictable weather patterns and rapid ecological change, that is not a very reliable guide. Also, guesswork does not work for larger fields with much higher levels of variability.
Enter the drone
Last year, Lankan scientists started experimenting with drones for farming. A research team of the International Water Management Institute (IWMI) tested an Electronic Bee (eBee), a survey-grade drone, in the skies above the Anuradhapura district.
Salman Siddiqui, head of IWMI’s geographic information systems, was quoted by SciDev.Net saying: “With a near-infrared sensor onboard, the eBee can help farmers identify stress in a crop 10 days before it actually shows up physically.”
As he explained, plants go into stress due to a shortage of either water or fertilizer, or because of a pest attack. Then its production work using sunlight – scientifically known as photosynthesis – goes down, which affects chlorophyll, a green pigment present in all green plants. Near-infrared sensors can detect this drop days before it becomes visible to the human eye. The eBee carries a 16 megapixel camera with a spatial resolution of up to 3cm – much more detailed than images generated by Google Earth (with resolutions of 5 megapixel ). Drone-taken images can be mounted together to produce a digital surface or elevation model in virtual 3D. These can also help identify areas vulnerable to flooding.
Commercial service
Now, drone-based smart farming is being rolled out on commercial basis. CIC Holdings PLC, a leading conglomerate, recently unveiled such a service.
CIC’s customised drones will provide farmers with a bird’s eye view in different wavelengths. Using imaging and sensor capabilities, the drones will be able to precisely identify factors like under-used areas of a field or disease-affected crop plants. This knowledge can then be used to minimise human bias and error in decision making, thus enabling higher yields at lower inputs.
Announcing the new service in August, CIC’s Managing Director Samantha Ranatunga said, “With this, we hope to reduce the misuse of agrochemicals (pesticides and fertilizer), while (also) reducing human exposure to agrochemicals in Sri Lanka. This will also help to cut down the excess amount of agrochemicals released to the environment.”
According to CIC Senior Scientist Manju Gunawardana, the drone will perform three main functions.
Observe: The drone will fly over the field and collect data, offering farmers a different perspective – one not noticeable at ground level. Drone-gathered data will help farmers decide what action is needed and where.
Measure: The multi-spectral cameras, sensors and software systems will read soil temperatures, assess soil nutrition levels, and show healthy and unhealthy crops apart. Analysing such data will also help in early detection of plant infections and pest attacks.
Respond: Having timely data enables more precise responses which, in turn, save water, fertilizer and other agrochemicals. For example, drone-gathered data can be used to customise fertilizer with lacking nutrients, and to apply pesticides or weedicides only where needed.
Initially, the smart farming service will be available for tea, sugarcane, maize, coconut and rice cultivations. “We have the required scientific data. We will definitely expand this to other crop sectors, livestock, fisheries, and environmental and human health factors as well,” Gunawardana said in an interview.
Drones could help overcome the shortage of labour faced by small and large farms alike. According to CIC, a drone will take around six minutes to spray one acre of a tea plantation. Contrast this with manual application, which occupies three to four people for up to two days.
Drones for all seasons
The drone-data service will cover all agro-ecological regions in Sri Lanka. “We have tested the technology under windy and misty/foggy conditions as well. We have the capability to handle the technology in all climates found in Sri Lanka. Agro researchers and farmers/planters have understood the advantages of using this technology to reduce the total cost of production,” says Gunawardana. CIC sees drones as part of a wider service package. “Our intention is not to sell drones. The operational model is to be a service provider with total solutions.”
The strength of the service is derived from an extensive set of data the company has gathered over time. It covers, for example, data on growth stages of plants and maturity of crops mentioned for different varieties/clones.
The service is already operational, but the cost packages are still being worked out. The total service is due to roll out by January 2017. “We are working with a few Regional Plantation Companies at the moment. Requests are flowing in from other sectors as well. It took several years for us to collect the necessary data sets from rice, tea, maize and sugarcane, and to validate the technology. Such data collection will continue,” says Prof Buddhi Marambe, a professor in crop science at the Faculty of Agriculture at Peradeniya University and a (non-executive) director of CIC Holdings.
How has the Department of Agriculture reacted to this innovation?
Extremely positive and encouraging, Prof Marambe says. “We have shown the technology and potential uses to the Director General, senior staff and researchers of the Department of Agriculture. We will apply the technology for the benefit of cultivation programmes conducted by the department in selected regions of the country by mid-September 2016 on the invitation of the Director General.”
Note: The operation of drones requires approval from the Civil Aviation Authority of Sri Lanka. Guidelines formulated in February 2016 can be found at: http://www.caa.lk/images/stories/pdf/implementing_standards/sn053.pdf