In theory, the idea doesn't sound bad: Instead of using tractors to spray large quantities of pesticides over fields, drones could precisely spray herbicides, fungicides and insecticides only where they are actually needed.
The plan would be to scan a field, identify affected areas and treat them selectively — significantly reducing pesticide use, according to the European Union's Omnibus X legislative package, which aims to simplify EU food and feed safety rules. After all, the bloc aims to halve the use of chemicals for plant protection by 2030.
Until now, however, the EU had a decades-old ban on spraying pesticides from the air over agricultural land. Exceptions applied only to difficult-to-work terrain, such as steep vineyard slopes. Omnibus X is now set to change that. In May, the European Council gave the legislative package the green light.
Drone use doesn't automatically mean less pesticides
"I think it makes sense in principle to distinguish spray drones from conventional aerial application from a regulatory perspective," said Thomas Daum, an agricultural economist and human ecologist at the School of Global Studies at the University of Gothenburg. Daum studies new technologies and their impact on agriculture. Compared with an airplane or helicopter, he said drones can generally spray more precisely.
However, Daum also cautioned that "the drone itself does not save any pesticide." He sees potential for using drones to respond more selectively to pest infestations — and thus reduce overall pesticide use. Another advantage for farmers could be the ability to respond quickly to an infestation "even when soils are wet or in difficult-to-access terrain."
"At the same time, this flexibility lowers the barriers to treatment and could therefore also lead to spraying being carried out more frequently overall," Daum said. This could result in a technological lock-in — meaning that more efficient application could reinforce dependence on chemical crop protection.
Omnibus X aims to save administrative costs, cash
Chemical pesticides have been cause for concern for many researchers. Omnibus X is intended not only to make it easier to use spray drones, but also to change the way pesticides are approved.
When the European Council approved Omnibus X in May, a group of researchers from 27 European research institutions voiced strong criticism. Among them was Carsten Brühl, a biologist at the Institute for Environmental Sciences at the Rheinland-Pfalz Technical University of Kaiserslautern-Landau. Brühl, who studies the effects of pesticides on the environment, called Omnibus X a "deregulation package" and is deeply alarmed by it.
To date, pesticide active substances have generally been approved at the EU level for a period of 10 years. Once that period expires, manufacturers can apply for renewed approval and must once again submit data on the safety of the active substance. Since this review process was introduced in 2011, it has resulted in 59 active substances not being reapproved, as they were deemed harmful to human health and the environment.
The main aim of the Omnibus X package is to cut administrative costs, reduce bureaucracy and "ensure fair treatment for companies while safeguarding fair competition within the internal market [...]," according to an EU press release.
Researchers warn Omnibus X could harm people, environment
European scientists have been critical of the EU proposal to cut red tape and deregulate the industry, because it could lead to many active substances being approved indefinitely, eliminating regular reassessments. They also say the transition periods after an approval expires would be extended from 18 months to three years.
Brühl called the idea "reckless." It would mean that even active substances suspected of being harmful to human health could remain on the market — like weedkiller glyphosate, for example, which has been linked to cancer in humans.
But the precautionary principle should apply, Brühl argued. This political principle holds that potential harm to people and nature should be prevented proactively, even when there is not yet conclusive scientific evidence.
The scientific evidence on pesticides is already incomplete. The risks posed by an active substance are inferred from the results of laboratory studies, Brühl said. But how that substance actually behaves over the long term under different environmental conditions and in combination with other pesticides is unclear at the time of approval. That is why regular reassessments are so important.
Brühl now fears Omnibus X could undermine scientific interest in studying these active substances. It would be unappealing for researchers "to engage with a system that can no longer be influenced anyway," he said.
Agriculture can work without pesticides
Brühl is certain the new EU legislation will not lead to lower pesticide use — not even with the help of drones and more targeted spraying. This approach, for example, does not work at all with fungicides, he pointed out. Fungicides combat fungal infections and have to be applied preventively because once a plant has become infected, it can no longer be saved.
But Brühl stressed there is another way: doing without pesticides entirely, through what is known as "integrated pest management." And this isn't some hippie eco-fantasy, but rather a concept for the sustainable management of harmful organisms enshrined in German law in 2012.
Shortly after the European Council gave the green light to Omnibus X and its new rules on drones and pesticides in May, the Scientific Advisory Board of Germany's National Action Plan for the Sustainable Use of Plant Protection Products reminded the German government of its own law in a statement. Brühl was the lead author.
Researchers wrote that integrated pest management calls for the use of synthetic chemical pesticides only as a last resort. The goal is to secure yields and quality while also minimizing negative consequences for people and nature and preventing resistance to plant protection products. This can work if certain crop rotations are taken into account and mixed cropping is favored. Pests can be controlled by attracting natural predators through flower strips or hedges, while weeds can be removed mechanically.
The problem: Spraying pesticides is often the less time-consuming and therefore cheaper option. There is also a persistent narrative that pesticides are necessary to ensure food security.
What this narrative leaves out is that monocultures and ecosystems disrupted by pesticides make agriculture more vulnerable to changing environmental conditions. That threatens food security, said Brühl, "because you have a system in place that can't cope with climate change."
