Arable farming needs to change in order to halt declines in biodiversity and prevent one of the worst mass extinction events in history, a leading US entomologist has warned.

Bold action is required by farmers to stop habitat loss and the unintended consequences of pesticide use having a devastating effect on insect communities, says Jonathan Lundgren of the Ecdysis Foundation and Blue Dasher Farm.

Highlighting that 60% of insect biomass had already been lost, the award-winning former US Department of Agriculture (USDA) scientist blamed the non-target effects of widely used systemic insecticides, such as neonicotinoids, for some of that damage.

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Pollinator loss

“Constant, low-level exposure to neurotoxins is having implications for non-target species. We are losing pollinators, insect predators and natural enemies because these products don’t stay put,” he says.

“We are finding them in places that they don’t belong. Burying your head in the sand is not OK anymore,” Dr Lundgren adds.

Central to this urgent situation is how the world is producing food, says the scientist, who stresses that agriculture has become too simplified.

“The rise of monoculture means that just four plant species are being grown across vast swathes of America. That’s not good for agriculture or the wider environment,” he says.

In the US, some 97 different pest chemistries are found in beehives today and Dr Lundgren points out that given the presence of neonicotinoids in the countryside, it begs the question as to whether conservation strips are helping or hurting our pollinators.

Next-generation pesticides

Dr Lundgren has similar concerns about the next generation of pesticides, known as RNAi insecticides, which work by blocking or silencing genes on a known insect genome. Although they are being marketed as very specific, he urges greater assessment of their risk.

“It’s not known whether they will silence the correct gene or an unintentional one. If it works on another part of the genome, could it also accidentally bind to genes in non-target species?”

He acknowledges that RNAi technology is not new and has been important in gene therapy.

“But it hasn’t been manipulated before. Tests have shown that 101 pesticidal development RNAi products all had exact matches in bees, although none of them were targeting bees,” he adds.

Farming solution

The solution, which can be provided by farming, is diversity. “We need to change agriculture. Farmers need to be able to produce nutrient-dense food profitably – there are too many third parties making money out of agriculture,” he says.

Dr Lundgren sees regenerative agriculture as a way of making this change. Reducing soil disturbance and increasing diversity will break the reliance on pesticides and raise profits – as it brings soil health benefits and attracts natural enemies.

“Pesticides are replaced by diversity. Yields are lower, by as much as 27%, but regenerative farms are twice as profitable. They also spend far less on seeds and fertilisers,” he adds.

As to why it isn’t already mainstream, Dr Lundgren explains that paradigm shifts take time. “Change is hard. Until now, the science hadn’t been done to help farmers make the transition.”

His advice to growers who want to change is to start small and develop their markets. “It won’t happen overnight but it will change your life. Transformational change always happens from the bottom up.”

Jonathan Lundgren was speaking at a recent BASE-UK meeting. BASE stands for Biology Agriculture Soil & Environment and is a member organisation that promotes conservation agriculture.

What is regenerative agriculture? The practices used in a regenerative system vary enormously, but the four principles remain the same: 1 Eliminate or reduce tillage Tillage has profound effects on both soil health and the biology of the system, as well as affecting the soil’s physical properties. As a result, agriculture is responsible for the loss of 4mm of topsoil every year. Rebuilding soil is done with biology, which is why earthworms are so important. In the US, cultivated fields have just 24% of the species that are found on undisturbed soils. 2 Never leave bare soil Plant cover protects the soil and supports the biology that drives the system. It also helps to retain soil and the roots increase water infiltration rates. Significantly more insect predators were found in no-till fields with cover crops than they were in bare fields, while a change in root biology is thought to be responsible for changes in pest survival and damage to crops. 3 Diversify plant communities A healthy system needs species and plant diversity increases biodiversity. Where plant diversity exists, there are greater species numbers and predator communities. Crop rotation and intercropping help with insect management, as they break disease and pest cycles. They also boost predator diversity and abundance, which increases consumption of pests. 4 Integrate crops and livestock Livestock should be used as a tool to add revenue streams, recycle nutrients, control weeds and increase diversity on the farm. Successful integration can be done on intensive systems and bees should also be considered as livestock.

Blue Dasher Farm Blue Dasher Farm in South Dakota is a research and demonstration farm, set up by Jonathan Lundgren to combine cutting-edge science with practical hands-on farming experience. The first in a planned network, it showcases farming methods that prioritise soil health and biodiversity while producing nutrient-dense food at a profit. On the farm, the team raises hair sheep, pastured pork and free range chickens. High-value seed crops are grown for cover crops and conservation mixes, while honey production from beehives is another important part of the operation. The aim is to show that it is a resilient business model for sustainable farming. Another demonstration farm is planned for Minnesota.