Drone use for forest fertilisation grows as emergency reports increase

Drone-assisted forest fertilisation is becoming more common in Finland, but emergency services are also receiving a rising number of drone-related reports, Yle reports.

Since late March, emergency call centres have received between three and ten daily reports about drone sightings, with roughly half coming from eastern Finland. Authorities had previously asked the public to report unusual drone activity following incidents involving Ukrainian drones entering Finnish airspace.

Taito Vainio, director-general of Finland’s Emergency Response Centre Agency, said the number of reports—while noticeable—has remained relatively low. “I initially thought we might see even more, but 3–10 daily reports is a manageable amount,” he said.

Fertilisation drones trigger alerts
Some reports have involved drones used for legitimate purposes, such as forest fertilisation. When Yle filmed a boron fertilisation operation in Kuopio’s Vehmersalmi, a local resident alerted emergency services about the large drone in use.

Mikko Rauma, sales coordinator for Silvadrones, which conducts drone fertilisation, confirmed the incident. “A nearby resident had already reported our drone to the emergency centre,” he said, adding that the caller quickly realised the operation was authorised.

Precision fertilisation from the air
Boron, an essential micronutrient for tree growth, has traditionally been spread by hand or via helicopter over large areas. Juhani Tiainen, a drone operator for Silvadrones, explained that drones offer greater precision, covering about one hectare per flight—or 20–30 hectares in a single day.

Markku Remes, a senior expert at the Finnish Forest Centre, called drone fertilisation “the future method,” noting a shift away from helicopter-based spreading. He estimated that boron fertilisation could increase timber yields by 15%, translating to roughly €11.2 million in additional stumpage revenue for North Savo alone based on last year’s state-subsidised treatments.

Boron deficiency is particularly common in inland forests, especially in eastern Finland, where historical slash-and-burn agriculture has depleted soil nutrients. Symptoms include stunted growth in spruces, rounded crowns in pines and birches, and crooked trunks.