Fewer pesticides on arable crops, possible | COP15

This young farmer from Montérégie, who had just finished farming the family, found himself at the head of a 420-hectare farm where wheat, corn and soybeans were grown, among other things.

Scratching the snow, he pulled out a radish about fifteen centimeters, tearing off some clover leaves and hairy vetches. These plants are called a cover crop. They are sown in the fall, just after harvest.

This is a crop that we will not harvest, we will not get any income from it, he explained. Its purpose is actually to grow and then return all the nutrients to the soil.

Cover cropping is a proven strategy in the United States to reduce pesticide use, but is not widely used in Quebec.

The principle is simple: the grower himself chooses the plants that will occupy his field during the winter. He will choose a mixture of plants that have the double advantage of being easy to destroy in the spring and of having the ability to provide nutrients and aerate the soil.

William Overbeek is experimenting with this method as part of his doctorate in environmental sciences at the University of Quebec in Montreal, which he is doing under the supervision of Professor Marc Lucotte. His research aims to reduce the use of chemicals in farm crops.

Once these weeds are established, we will kill them with minimal glyphosateexplained his thesis director.

In Quebec, many producers will make two or three glyphosate applications per year. Our study aims to show that with a single pass, at the right time, together with the presence of cover crops, we can manage to control the spread of weeds. »

A quote from Marc Lucotte, professor at the University of Quebec in Montreal

Marc Lucotte, professor in the Department of Earth and Atmospheric Sciences, UQAM

Photo: Vincent Rességuier

Crop rotation

According to this scientific experience, weeds remain the main enemy of field crops in Quebec and, by extension, the main reason for the use of pesticides.

Using less is a laudable goal, but the challenge is to maintain performance, he says. Currently, it is not always easy, if not impossible, to do without substances such as glyphosates, the most widely used herbicide in the world.

No one wants to take antibiotics over and over again, we take as little as possible, but when we are sick and we need to get rid of a bad bacteria, we are very happy to rely on it. Same thing for glyphosates, when you need to clear weeds. »

A quote from Marc Lucotte, Department of Earth and Atmospheric Sciences, UQAM

The young farmer experienced this to his cost. Last summer, while conducting a herbicide reduction test, one of William Overbeek’s fields was colonized by nightshade. He lost control. Because of this, part of his harvest was wasted and the nightshade berries damaged his machinery at harvest time.

This unfortunate event occurred during a crop rotation experiment. Another tried and tested option used by William Overbeek to take a break from herbicides.

Because it often happens that unwanted plants get used to weedkillers. Then it is necessary to remove heavy artillery with highly toxic products, its use proves more complicated. Then we use our low-impact herbicides and our high-impact herbicides, we can’t separate themsaid the planter.

Experimentally weed.

Experimental weeder that makes it possible to combine weeding between the rows, watering the row and sowing the cover crop.

Photo: Vincent Rességuier

Drones to reduce pesticide use

To limit his use of pesticides, Mr. Overbeek also turned to innovative technologies.

He is currently testing a tool that will allow him to reduce the amount of herbicides used at the time of their application by 66%.

This is a weeder that will slightly turn the soil between the rows, while watering the row of cultivated plants, and finally will sow a cover crop.

This multifunction module is installed on the back of a tractor and it is in surgical precision, it continues to the nearest centimeter.

This is now also the case for many agricultural implements that increasingly rely on digital mapping. William Overbeek owns several drones equipped with cameras, with which he draws a very accurate picture of his fields.

William Overbeek, doctoral student at UQAM and head of a farm.

William Overbeek conducts experiments with a drone equipped with cameras and a tank with a diffuser.

Photo: Vincent Rességuier

In the next few years, he wants to develop application maps to systematically locate weeds in his crops.

Subsequently, a tractor with a watering can or even a drone with a watering can will apply chemicals exclusively to areas of danger.

There, too, the gains must be substantial, as it is currently a strategy universal for an entire field, or even an entire farm, says Marc Lucotte.

With the accuracy of digital mapping, the plots will be checked per square meter.

All this will allow a significant reduction in all the chemicals that can be used to get rid of insects, fungi and weeds, the researcher concluded.

Marc Lucotte, professor in the Department of Earth and Atmospheric Sciences, UQAM.

Marc Lucotte in his laboratory at the University of Quebec in Montreal

Photo: Vincent Rességuier

A revolution is taking place in the world of agriculture

Marc Lucotte agrees that we will have to wait a few years before widespread adoption of these new technologies. He was looking forward to the horizon of ten years, or even a little more.

There is all the digital literacy that needs to be taught to producers so they can use these new tools.he says.

And the big agrochemical companies want to take advantage of this transition.

Marc Lucotte says companies like Bayer are investing millions in new technological tools. They are gradually moving away from chemical products, but clearly placing themselves in the market for high precision devices.

According to him, Quebec should achieve its current goals without too much difficulty. 4,300 tons of pesticides were used in 2019. The plan provides for a reduction of 500 tons by 2030, or 11%.

An unambitious plan if we compare it to the goals of the COP15 on biodiversity in Montreal: target 7 proposes to reduce the use of pesticides by at least half or two thirds by 2030. It remains to be seen now what tags adopted in the final text.

Drone in a field in Montérégie.

Drone used by William Overbeek for digital mapping.

Photo: Vincent Rességuier

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