The Sky's No Limit: Using Drones For Precision Farming

To stay profitable in an increasingly tough environment, farmers must use their land and other resources to their maximum potential. The amazingly detailed imagery captured by unmanned aerial vehicles can help achieve this. Lloyd Phillips visited Agri-Sense International to find out more.

In its six-year existence, Agri-Sense International, which is based in Hilton, KwaZulu-Natal, has used its unmanned aerial vehicles (UAVs) to digitally map more than 500 000ha in 13 countries.

This includes the world’s largest topographical survey ever undertaken by drones: 106 000ha in 106 flights over 28 days in Belize in Central America.

And in a more recent survey in Ghana, the company used two UAVs to map 36 000ha, a process that required 80 hours of flight time.

Conducting surveys on this scale is impressive enough, but it is what the company does with the data that is perhaps more important.

Agri-Sense has two core functions, says managing director Russell Longhurst:

• The use of UAVs to collect the data required to generate detailed digital terrain models for clients, especially for the further development of agricultural land;

• Monitoring crop health and productivity using near-infrared (NIR) camera technology and then generating a normalised difference vegetation index (NDVI).

“Commercially available satellite imagery has its uses, but is often not as precise and detailed as imagery collected by UAVs flying only a few hundred metres above the ground,” explains Longhurst.

BETTER SENSORS

The company currently owns two Sky-Watch Cumulus C1 fixed-wing drones and five multi-rotor DJI Phantom 4 Pro UAVs for its land surveying and crop monitoring operations.

“The Sky-Watch Cumulus gives us far less blurring of the images captured and can also be equipped with better sensors,” says Longhurst.

The imagery captured by the UAVs is converted into 3D digital maps. These allow Agri-Sense’s clients to precisely calculate any of a wide variety of agricultural design needs.