Biobeds tackle pesticide waste, boost consumer trust

Biobeds can be set up in-ground or above it. A raised biobed at the Canada Saskatchewan Irrigation Diversification Centre at Outlook, Sask., creates a place for microbes in to degrade pesticides and reduce the risk of contaminating water with sprayer waste.  |  File photo

Pesticides are an important tool used in modern agriculture, and for the most part, farmers are getting better at communicating this to consumer audiences.

What we rarely talk about, however, is how we dispose of leftover effluent from spray operations and cleaning. While best practices for disposing of pesticide waste certainly exist, pesticide residues are still somehow often detected in wetlands, rivers, lakes and groundwater.

The Canadian Centre for Food Integrity’s public trust research in 2017 reveals that only 34 percent of Canadian respondents believe farmers are good stewards of the environment. Not only does this affect consumer preferences, but it also affects Canadian agriculture’s brand both locally and abroad.

“So imagine you are on an airplane and the passenger beside you asks how you dispose of the pesticide waste on your farm,” says Tom Wolf of Agrimetrix Solutions.

“Could you answer them honestly and feel good about your response? This is one of those inconvenient things we tend to avoid talking about because of how we are currently dealing with it.”

Wolf speaks to 5,000 to 10,000 producers a year, with most producers dictating conversations toward improvements in productivity and efficiency of spray operations rather than ethical pesticide disposal. He said this is because farmers haven’t exactly acknowledged that there is an issue.

“There’s that place on the farm where we let things go at the back of the yard, and that’s what we need to address in a way that makes sense,” he said.

With productivity and efficiency top of mind for applicators, it can be a challenge for producers to refocus efforts on improvements in other areas, especially to areas that don’t necessarily improve their bottom line. Any viable solution would need to have little impact on the demanding spray season while allowing farmers to dispose of pesticide waste safely and efficiently.

An inexpensive and effective Swedish invention, known as a biobed, is likely an unfamiliar term for Canadian farmers. It is a below ground or above ground site where a sprayer is filled, tested and cleaned. The waste water from these processes is filtered into a biomix, which contains millions of microbial bodies that drive bioremediation, or the breaking down of pesticide waste.

The biomix consists of three ingredients: straw, soil, and peat-free compost.

“The key ingredient is straw, which forms a white mould that facilitates the microbial breakdown of pesticide waste,” Wolf said.

He said the end result of the bioremediation process is pure soil and clean water, which could actually be used for subsequent spraying or washing.

If done correctly, a biobed can almost completely eradicate the effects of pesticides in soil and water systems.

And Wolf said there is no capacity limitation to biobeds.

“The more you feed them, the more they grow, so the capacity of a biobed to break down pesticides increases as more effluent passes through them,” he said.

“The concept is pretty simple. It’s about keeping pesticides where they belong.”

Wolf said he stumbled across biobeds during his first trip to Sweden in 2001.

It’s likely no surprise to anyone that Europe is the birthplace of the biobed because stringent regulations in the agri-food sector ensure farmers comply with robust purchasing and handling standards for pesticide use.

Biobeds currently aren’t mandatory in Europe, but farmers there have embraced the idea by designing on-farm biobeds that fit into the demanding spray season while having little impact on productivity.

More than 5,000 on-farm biobeds can be found across Europe, while interest is increasing in Latin America.

Upon his return from Sweden in 2001, Wolf began applying for research grants to study the effectiveness of biobeds under western Canadian conditions. As a result of these initial efforts, extensive biobed research has been conducted within the last 10 years by Agriculture Canada at four government sites in Alberta and Saskatchewan, and the results look positive.

Researchers have found that effluent passed through a properly constructed biobed contains 90 to 99 percent less pesticide than the original solution.

Based off of this research, Agriculture Canada recently released a construction, operation and maintenance manual for managing pesticide rinsate under Canadian conditions to serve as a resource for farmers designing their own on-farm biobed.

“The greatest barrier to uptake is recognizing the need for one, and then scaling it for the size of equipment we have here on the Prairies.” Wolf said.

With more information available and a manual to help farmers with the design and planning, this could change.

“We have evidence that pesticides are appearing in places they don’t belong, but there is limited data on how and when they are getting there,” Wolf said.

He believes that proactive approaches to solving problems are most effective when farmers initiate the changes themselves.

“Canadian agriculture has done incredibly well at adopting new technology without government pressure,” he said.

“Pulse width modulation, low drift nozzles, and overlap control are a few examples of this.”

Wolf said the industry needs better messaging about biobeds.

“Right now most people don’t know what they are or why they should have one,” he said.

“My principle is this: don’t allow pesticides to go where they don’t belong.”

Although biobeds offer no tangible return on investment, there’s value in doing the right thing as an industry, not only for Canadian agriculture’s brand but also for the potential long-term and somewhat unknown environmental impacts that have the potential to plague an industry or warrant regulatory interest.

Katelyn Duncan, P.Ag., BSA, is a farmer, agrologist and crop adviser with Western Ag.

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