In fact, this whole area is part of scientific work to help farmers cut down on their use of pesticides, herbicides and chemical fertilisers.

“I felt these products were dangerous,” said farmer David Bonneau as he hunched over the little wildflowers – veronica and hickweed, “and the general public is asking for reductions.”

One of his experimental plots is treated the standard way, with chemical weedkiller; another he weeds mechanically with a harrow whose teeth tear up the wild plants; while a third will not be treated at all.

He is part of a project involving 400 farms and around 40 villages in the Deux-Sevres region of western France, where scientists are experimenting with different techniques to cut pollution.

Researchers from French agency CNRS support volunteer farmers to reduce the use of pesticides – which are probable sources of cancer and fatal to birds – as well as water-polluting chemical fertilisers, the prices of which are skyrocketing.

Excessive use of fertilisers or pesticides can affect small and large crops, and farmers in countries such as Vietnam, Laos and Cambodia are misusing pesticides with potentially harmful consequences, according to experts at the World Vegetable Center in Taiwan.

“It is important to realise it is farmers themselves who are most affected by the misuse of agrochemicals,” said Pepijn Schreinemachers, a researcher there. This could be using too much of a chemical, unsafe techniques, or the use of the wrong products.

“Every farmer can share details about pesticide-poisoning incidents they have experienced, ranging from skin rashes to vomiting and unconsciousness. Still, most strongly believe that pesticides are necessary for farm production.”

So how can they be persuaded to change? Robert Finger, head of farming systems research at ETH University of Zurich, believes there needs to be a middle ground between full organic farming and chemical-heavy conventional agriculture.

Clear long-term public policies should help support the development of new technologies, as well as investment in pesticide-free production and techniques like growing legumes among crops to reduce the need for fertilisers, he said.

The costs of pesticides and fertilisers should properly reflect the damage they can do, Finger added.

And in regions where “highly toxic” products are not being used safely, Schreinemachers said they should be banned outright, or heavily taxed to discourage use, while encouraging alternatives like biopesticides.

To help farmers overcome worries about making a switch, CNRS researchers are considering a mutual fund that would compensate them in the event of losses linked to the reduction of synthetic fertilisers and pesticides, a model that already exists in Italy.

Green growth

So far, David Bonneau has seen savings on the costs of buying weedkiller and equipment. When he made his first attempts at ditching the chemicals, he used his neighbour’s machinery; but since then, a more efficient device has been purchased by the agricultural cooperative.

The proof, however, will only come at harvest time, when researchers will measure the wheat yields of each plot to examine the impact of the herbicide reduction.

In Deux-Sevres, “we have demonstrated that conventional farmers can reduce nitrogen and pesticides by a third without loss of yield, while increasing their income because they lower their costs”, said Vincent Bretagnolle, research director at CNRS.

But changing behaviour long-term is another challenge. “Even the farmers who participated in the experiment and saw the results with their own eyes did not noticeably change their practices,” he added.