Why Drones Are Replacing Traditional Crop Spraying Methods

A DJI Agras T30 spraying at night

NDVI Mapping with Mavic 3M

 Crop Spraying Science has advanced a lot in the last five years.

From Crop spraying with large drones to spray booms with smart cameras to detect and spot treat weeds, Agri-science is an exciting field that’s rapidly transforming the way we grow food and manage natural resources. With innovations like precision irrigation, cm accuracy field mapping and plant health analysis with multispectral drones, autonomous tractors, and AI-driven soil analysis, to understanding the soil biology necessary for peak plant health, farmers are now able to boost yields while minimizing environmental impact. The fusion of technology and agriculture isn’t just about efficiency—it’s about sustainability, resilience, and feeding an ever-growing global population with smarter and better farming practices.

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A really exciting field has been aerial applications with drones, whether spraying or spreading.
Modern drones are large and fast enough to be able to work faster, more precise and more efficient than boom sprays.  Boom sprayers have always had the advantage of economically laying down high volumes for pesticides that require it such as pre-emergence herbicides.  The release of the Agras T100 with it being capable of carrying up to 100L payload per flight, with extended spray package being able to spray up to 40 litres per minute, laying down 100L/Ha is not far-fetched or expensive with drones application.

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Aerial application with air tractors has always been the go-to for large fields, since they are able to spray high volumes of pesticide at very high speeds.  The downsides are that aircraft are not as precise as other methods and also suffer highly from drift and evaporation.  The reason for this is due to the time the pesticides are in the air before they reach the ground, which is compounded by the wing vortexes.  Boom sprays have the best performance, since they are very close to the crop.  Drones come in a close second with a lower speed than aircraft causing less of a vortex, so time in the air is a lot less.  Drones also have strict terrain-following so the height above the crops are very consistent.  With the T100, which can easily cover 200+ hectares each per day, larger and larger fields can be covered with drones.

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When it comes to costs, smart boom sprayers that regulate flow well are pretty costly to buy and maintain, whereas drones are comparatively cheap.  Air tractor contractors cost similar to drone contractors, so in the busy season, much of the load of air tractor contractors can be offloaded to drone contractors, since they can cover larger fields than before.

Mapping is very easy on DJI Smart Remote

Drones are really easy to use as well.  Mapping and setting up fields are really simple and can be done from the remote with ease, with more accurate mapping being able to be done with the drone and RTK.  Setting up for spraying precisely is as simple as dialling in how many L/Ha you want sprayed and the drone calculates flow rates for the selected swathe width and flying speed. automatically.  The drone flies on autopilot the whole time flying out and keeping lanes with GPS technology.  Modern drones such as the T100 have accurate 3D Radar and LiDAR technologies that allows the drone to know exactly where there are obstacles and hazards in the 3D space around it.  When the spray tank is empty, the drone will return to home to be refilled.  All the relevant stats are displayed for you to verify that the spray work is satisfactory.

Tools such as the Agras Smartfarm app can be used to monitor your spray work and to see the stats of each flight.  Spraying accurately has never been this easy!

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