VANCOUVER, B.C. – Millions of research dollars are being devoted to developing best management practices for confining nutrient runoff to farm fields and out of waterways. A new study from the University of British Columbia (UBC), however, is devoted to keeping fertilizers, pesticides and herbicides attached to crop plants and out of farm fields.

According to lead researcher and chemical and UBC biological engineering professor John Frostad, adding a simple polymer known as polyethylene oxide to commonly used agrochemicals could reduce the amount of chemicals lost to the environment by at least 50 percent. If the technology proves successful in field trials and can be brought to the market, it holds the potential to significantly reduce pollution and chemical use in agriculture.

“This reduces the amount of spraying that farmers need to do,” Frostad said. “We had an idea that if we could reduce the amount of fertilizer being applied to a plant, we could at the very least reduce the amount being lost from the plant.”

Active AgriScience, a leading provider of technologically advanced biological and chemical seed treatments, foliar plant nutrition and nitrogen management, agreed to fund Frostad’s initial research in collaboration with a government funding agency. His team focused on common nutrient loss causes, including spray drift, and began experimenting with applications of variously sized droplets.

“The trouble is that you can lose the application because the droplets are too light and blow away, or are so big and heavy they bounce off or splash. There is not an optimum droplet size,” Frostad said. “Prior research had discovered that when you use individual droplets with the polymer it has a lower tendency to bounce away. We thought we would build on that research and focus on the bouncing problem.”

In order to conduct the study, the UBC research team constructed a lab-scale device that allowed liquids to be sprayed onto surfaces through agricultural-use spray nozzles. The device also measured how much liquid remains on a surface after it has been sprayed at industrial pressures and deposition rates in a laboratory setting.

“The apparatus is the first of its kind and it actually quantifies how much liquid remains on a plant. We made applications to plants and a couple of different model surfaces and showed that, indeed, we could increase how much material stayed on surfaces when we added the polymer,” Frostad explained. “Depending on the situation you can be using at least 25 percent less fertilizer, and expecting more of it to stay on the plant.”

Manufacturers mixing small quantities of polyethylene oxide with agrochemical products should not result in much of an increase in the price farmers pay for the products, according to Frostad. “We are recommending adding this polymer to solutions at a rate of 0.1 percent by weight, so it is a very tiny amount. It is also not an expensive polymer,” he said.

Field demonstrations are being planned for this spring by Active Agri-Science in order to further develop the effectiveness of the polymer additive. Researchers also hope to be able to demonstrate a yield bump from improved plant nutrient retention, along with cost savings from reduced fertilizer usage. 

“I don’t think there will be much regulatory approval required for this, so I think the question is who will be the first company to go ahead and put it in their product and demonstrate that it works,” Frostad said. “New formulations of agrochemicals that include these additives could allow crops to be sprayed more efficiently, cutting both environmental pollution caused by agrochemicals and the amount of chemicals that need to be used in the first place.”

Further testing will likely be required before the polymer additive can be introduced to the agrochemical market, according to Jean Payne, president of the Illinois Fertilizer and Chemical Association.

“It’s an intriguing idea, but the difficulty in polymers is will they allow for release of the nutrient or chemical at the right time? You are still depending upon the right moisture, temperature or biological activity to make it happen,” Payne told Farm World.

The UBC research was recently published in Physics of Fluids.