Drones: boosting yield and beating erosion

Farmers are continually required to do more with less: in other words, improve yield without boosting inputs. Optimising orchard health is therefore crucial, and it starts with the correct diagnosis. This is where drone technology is showing increasing promise, as it reveals what is invisible to the naked (and earthbound) eye. Lindi Botha reports.

- Lindi Botha

FAST FACTS

Drones provide aerial imagery of plant problems well before they become obvious to an unaided observer.

Aerial mapping of a large farm can be completed in two days using a drone.

Drones can help a farmer with faster decisionmaking, which in turn can lead to better yield.

The contribution of unmanned aerial vehicles (UAVs) to sustainable agriculture is growing rapidly as the industry learns to harness this technology. According to Berkshire Hathaway’s Business Wire website, the global agriculture drone market was estimated to be worth US$2,15 billion (about R33 billion) in 2021, and this is projected to grow to US$6,72 billion (R103 billion) in 2026.

Since UAVs can survey extensive surface areas while pinpointing problems on a minute scale, they are far more efficient at inspecting orchards or lands than a farmer on foot. Moreover, their infrared sensors can detect problems not seen by the human eye.

Research on the impact of drones on precision agriculture conducted by Ibrahim Naji at the University of Texas in the US explains that plants reflect near-infrared (NIR) light, but that this ability deteriorates as the leaves die.

“Therefore, the NIR sensors are designed in such a way that they are able to monitor the difference [between] the NIR reflectance and visible reflectance, through a calculation known as the normalised difference vegetation index (NDVI). A strong NDVI is indicative of healthy plants in an area, while a weak NDVI can be interpreted as problem areas in a field.