How agricultural drones are rising above environmental problems

There was a time when unmanned aerial vehicles, or drones as they are now more commonly known, were the preserve of military generals – with their first recorded use taking place in the First World War. Since then, they have become a more familiar part of everyday life, having found favour amongst photographers, and even catching the attention of multi-national delivery companies. One other industry in which their use is gathering pace is the agricultural sector, and it could spell good news for our natural environment.

Solving problems with flying colours

A worrying environmental problem – but one thankfully now receiving much more attention – is the deteriorating condition of the world’s soils. A report from the United Nations Food and Agriculture Organisation indicates that a third of all of the world’s land is moderately to highly degraded, owing to erosion, compaction, salinisation, acidification, and toxification from industry. In addition to this, there have been ominous accounts of there being only 60 or so harvests left if we continue to abuse soils in the way which we have historically done so.

One issue in particular with soil is compaction, which is often linked to heavy agricultural machinery such as tractors and quad bikes being used on farmland. Compacted, less porous soils not only make it more difficult for plants to take root, but they also struggle to retain water, which can increase susceptibility to flooding and increase fertiliser and pesticide run-off (leading to eutrophication and toxifying watercourses). Soil can also be a valuable carbon sink, which helps mitigate climate change, but the ability to sequester carbon diminishes when compacted. Though still in the early stages of development, drones, which can aerially sow seeds, for instance, have been proposed as a novel way to remove heavy equipment from farmland, therefore minimising the extent to which soil compaction occurs.

One area of agriculture in which drones are already quite established is administering pesticides to crops – indeed, the Japanese have been using drones to do so on their rice paddies since the 1980s. Drones are far less indiscriminate than conventional methods of spraying pesticides, which has environmental benefits. By virtue of being able to fly close to crops, drones can spray only the plants which farmers want to target, which lowers the amount of pesticide used.

Although civilian drones are perhaps most commonly known to be used by photographers and alike, shrewd farmers have also come to understand the advantages of combining photographic equipment and aerial units – a development which should benefit the natural environment. Specifically, farmers are using camera-equipped drones to monitor the health of crops and orchards, as they can more easily spot diseases from a higher vantage point than would be the case otherwise. The most advanced drones can also gather images of farms with different multispectral lights, such as infrared, which can further reveal hitherto unknown information to farmers about the health of their crops. By being able to better identify problems, such as fungal diseases, farmers can take evasive action more quickly – in some cases up to ten days more quickly – and remove stricken plants from their fields, therefore stopping pathogens in their tracks and preventing them from causing damage further afield.

A final way in which drone technology in agriculture can reduce the sector’s impact upon the natural environment is simply through how they can boost yields. Higher yields mean less land needs to be sacrificed to growing food, thus preserving more vital habitats for native wildlife. In addition to reducing pesticide and fertiliser use and bolstering biosecurity, drone monitoring of crops can boost yields by providing farmers with information on, for instance, how well parts of their farm are irrigated and soil nutrient compositions. Farmers can then respond to this information to make changes to their land, or better distribute the fertiliser they put onto it. One technology company which operates in the agri-drone market claims that yields on certain crops can increase so much as a result of using drones that the return on investment can exceed $15 per acre of land farmed. 

The sky’s the limit

Agriculture is a science, and as such it has been constantly innovating. Despite having been in existence for some time now, drone technology looks set to make inroads in the industry – and revolutionising it as it does. Indeed, Bank of America Merrill Lynch anticipates farming to be accountable for four-fifths of the commercial drone market in the future, generating tens of billions of pounds of economic activity in the process over the next decade.

Drone technology in the agricultural sector will almost certainly bring about vast productivity increases, with one estimate claiming that drone-planting systems can achieve an uptake rate of 75%, and reduce planting costs by 85%. As agricultural productivity has started to plateau in recent years and decades – total output from UK farms has changed fractionally since the 1980s – the farming community is beginning to look to new technologies like drones which could prove to be the next revolution in the industry.

But these robots in the skies could also be a blessing for the environment below. As the technology is finessed, we can call upon drones to be gentler on our precious soils, less intensive in our use of harmful pesticides, become better at spotting potentially devastating diseases, and lower the overall footprint of our farming operations.

And it would seem that the Government is on board, too. Only this year, both the Environment Secretary, the Rt Hon Michael Gove MP, and the Chair of the House of Commons Environment, Food, and Rural Affairs Select Committee, Neil Parish MP, have indicated their desire to see Britain become a world leader in agricultural drones and other labour-saving, environment-improving technology. Indeed, drones look increasingly likely to be a clever solution to some of the environmental challenges currently associated with the agricultural industry.

Eamonn Ives is a Researcher at Bright Blue

Creating a buzz about pesticides

Earlier this week, the Centre for Hydrology and Ecology provided the latest twist in the ongoing debate about the impact of pesticides on bees. Their study concluded that half of the decline in the bee populations they observed over 18 years could be attributable to the use of a controversial type of pesticide, neonicotinoids (neonics).

Campaigning organisations like 38 degrees and Friends of the Earth have mobilised significant public support for an outright ban on neonicotinoids. In 2013, a YouGov poll found that 71% of the population would support an outright ban on neonicotinoids.

Given the importance of bees for sustaining our natural environment and our domestic farming industry, the concern is well-placed. The stakes are high for the agriculture sector, as 30% of crops globally depend on natural pollinators such as bees, which are worth an estimated $360 billion to the industry.

The decline of bees

There is a widespread perception that bees are in decline. There has been an observable loss of wild bumblebee species, with two out of 26 species from 80 years ago no longer present in the UK and a further six now found in much smaller areas of the country. Similarly, since the Second World War, the number of honeybee colonies has fallen from 400,000 to around 130,000 in 2013.

However, thankfully, there does seem to have been a very recent recovery in bee numbers: between 2008 and 2012, government figures show an increase in the number of honeybee colonies.

The decline in honeybees has been observed around the world, and is often referred to as ‘Colony Collapse Disorder’. A range of causes have been adduced for this: the Varroa mite, poor nutrition, urbanisation, agricultural intensification, habitat degradation, and climate change.

But some have attributed part of the loss of bees to the use of certain pesticides and, in particular, neonics. First used in the 1990s, neonics are coated on to the seed of crops, such as oilseed rape. The pesticide is then absorbed and transported throughout the plant. This prevents pests, like flea beetle larvae, from destroying the crop.

There is now a significant body of academic evidence showing harmful effects of neonicotinoids on bees. A 2015 study found that the bumblebees’ pollinating services are reduced by exposure to neonics. Another 2015 study, which carried out a large field trial of honeybees that came into contact with neonics, found a correlation between honeybee colony losses and the use of neonics. A 2016 study observed a decline in brood production in colonies exposed to neonics. 

Government response

The regulation of pesticides is currently an EU competency. Depending on the outcome of the Brexit negotiations, the responsibility for pesticides may be returned to the UK government. In 2013, the EU imposed a moratorium on the use of neonicotinoids, on the grounds that they posed a threat to bees. An EU review on whether to lift the ban on neonicotinoids will be concluded by January 2017.

The UK Government is opposed to the EU ban of neonics. It has published two literature reviews, one from 2012 and the other from 2013, assessing the link between pesticides and the decline in the bee population. They found no unequivocal evidence of ‘sub-lethal’ effects on pollinators. They criticised some of the studies as failing to accurately recreate real-life conditions in the field with laboratory experiments.

In 2013, the UK Government was forced to implement the ban on the use of neonics. But, while they have no choice but to enforce the EU regulation, UK ministers have the powers to grant emergency authorisation for the use of neonics in limited circumstances. They did so in 2015 for around 5% of the UK’s oilseed rape crop, following the advice of their scientific advisory body, UK Expert Committee on Pesticides.

The Government, nevertheless, has shown concern about the bee population, with the publication of a ‘National Pollinator Strategy’ in 2014. The strategy does acknowledge potential adverse effects of unregulated pesticides on pollinators. But its response is only to keep the scientific evidence on pesticides under review. The majority of the proposals involve government working in partnership with farmers, landowners, and beekeepers to improve land management and husbandry practices on a voluntary basis.

Conclusion

There is growing evidence of a causal link between neonicotinoids and bee decline. This week’s study by the Centre for Hydrology and Ecology further strengthens the case. But whether the harm is yet sufficient to merit a ban, or whether the trade-off is acceptable in order to improve crop yields, is a matter of judgement. It is also hard to assess whether it is primarily neonics driving the decline in bee numbers.

Oilseed rape cannot be grown without some kind of pest control mechanism. A vital issue that policymakers must consider is whether the risks of neonicotinoids outweigh the risks of the alternative pesticides. For this reason, the best hope of a solution lies in further research and development of alternative, more sustainable pesticides.

Sam Hall is researcher at Bright Blue