An Ontario Phosphorus Reduction Strategy

Sunday, March 8, 2015

Farm organizations seek a 'farmer-driven, science-based blueprint' With the Ontario government just beginning to develop its approach and many questions unanswered, regulation is the elephant in the room for the farming community. If it comes, says one farmer, 'it had better be based on good science'

by MARY BAXTER

It has the clap-along rhythm of the old spiritual "Dem Dry Bones." The tiles in Laurence Taylor's field connect to a drainage ditch. The ditch connects to Hullett Marsh. Hullett Marsh connects to South Maitland River. South Maitland connects to Maitland River. And Maitland connects to Lake Huron. So the water flows.

Back in 1969, the year Taylor began farming full-time on his farm near Londesborough in Huron County, it was mostly that first connection – the field and drainage ditch – which preoccupied him. More specifically, the detrimental impact of soil erosion on production. Water that flowed from his property might well remove not only soil, but also the nutrients intended to help his crop grow. So, in 1985, he took the radical step of abandoning the plow and embracing the modified no-till field management approach he employs to this day.

As he grew older, Taylor's perspective on the relationship between farming and the environment progressed beyond that ditch, beyond even the marsh, the river and the lake. How to balance the task of feeding the world with protecting the planet became his focus. "You really have to take a lot more of a holistic view and try and hope that agriculture is going in a direction that will protect the environment – not just the soil environment that we work with every day but the Great Lakes, and the impact we have on the flora and fauna that are there," he explains.

He considers scientific enquiry the best tool to quantify the relationship between agriculture and the environment, and to determine what to do when the needs of one are at odds with those of the other. Therefore, Taylor was all in when he was approached in 2011 to join a small group of farmers who wanted to work with researchers in finding out if there really was a link between no-till farming and an increased loss of dissolved reactive phosphorus from farm fields, as some U.S. studies were showing.   

Nearly four years have passed since a satellite captured an image of an algae bloom spreading out of control like a tumour in Lake Erie's western basin. Back then, fertilizer runoff from field crops in the Maumee watershed in the United States was blamed – just as it was last August, when the same blue-green algae called cyanobacteria shut down Toledo's water system for a weekend.

Within that four-year period and in response to concerns about Lake Erie's declining health as well as other areas of concern within the Great Lakes system, governments on all sides committed millions towards solving the problem linked mostly, although not exclusively, to increasing amounts of dissolved reactive phosphorus (the water soluble form of the fertilizer) in the lakes.

Two key government agreements have been signed: the Canadian and U.S. governments' 2012 update of the Great Lakes Water Quality Agreement, signed in 2013; and the Canada and Ontario Great Lakes agreement on quality and ecosystem health signed in December. Ontario released its Great Lakes Strategy in 2012. In 2014 the International Joint Commission, an organization that helps the two countries regulate and investigate shared water uses, released recommendations on how to improve Lake Erie's water quality.

Factors other than farming are identified as potential culprits in the mountain of documents supporting all of these government initiatives. Urban runoff. Municipal sewage treatment facilities. Industry. Discharges from vessels. Climate change. Even interactions within the lake environment. Yet agriculture is hardly considered a minor player. Of the Joint Commission's 16 recommendations, for instance, six tackle agricultural practices.

Conflicting evidence
Within the same past four years, we have seen a tremendous amount of knowledge amassed about how dissolved reactive phosphorus might be generated on farms, how it might escape, and ways to mitigate its loss.

There is research that indicates the combination of no-till, broadcast fertilizer and heavy rain after fertilizer is spread can lead to large amounts of phosphorus loss on the clay soils in Ohio and in the far reaches of southwestern Ontario.

On the other hand, early results from the work being produced by the team of researchers conducting studies on Taylor's and the other farmers' properties are not turning up evidence of an enhanced dissolved phosphorus loss in its no-till sites relative to its tilled plots, says Merrin Macrae, an associate professor in geography and environmental management at the University of Waterloo. Researchers are now trying to unravel why that is. "There are many possible answers for this," says Macrae, who is one of those leading the on-farm research. "It might be soil type and it might be management and it might be climate. We are testing all of those things now."

These studies, the first to examine phosphorus loss through both surface and subsurface drainage routes for the entire year, are also indicating that, in much of Ontario, winter loss presents one of the greatest risks because that's when the greatest amount of water will leave the field. Moreover, work done by Chris Van Esbroeck, a Waterloo post-graduate student and now soil and water specialist at the Maitland Conservation Authority, shows that while tiles are the dominant way in which water will leave the fields, surface runoff, when it occurs, will have a greater concentration of dissolved reactive phosphorus than water that comes from tiles.

"Our studies have trained us to think that it's not just a surface water or a sub-surface issue. It's not one or the other and in our management we have to tackle both of those pathways," says Macrae. "And you can't look at what's happening in August and think that represents the rest of the year."

Other research that took place over roughly two and a half years in Huron County, beginning in 2010, shows that when it comes to overland runoff, intermittent channels that appear to exist only during storms and other high-water flow events are of particular concern.

Potential solutions are beginning to be tested throughout Ontario's farm country. The Huron County study evaluated five best practices – nutrient management reduction, conservation tillage, cover crops, water and sediment control basins, and grass filter strips. Its findings indicate grass strips were effective in reducing total phosphorus loss by 47 per cent and soluble reactive phosphorus by 63 per cent, but were not effective in filtering nitrate.

As well, phosphorus treatment systems that use slag (a byproduct from the steel industry), red iron-based sand and Chitosan (made from the exoskeletons of shrimp) are being tested in the Upper Thames River watershed.

Industry, too, is looking at ways to minimize risk of nutrient loss, and has launched a pilot of the 4R nutrient stewardship program with 10 growers in Ontario.

Developed in the United States, the program promotes reducing nutrient loss by employing a precision approach to the application of fertilizer that takes into account the "right" source, rate, time and place. The program, launched in Ohio, Michigan and Indiana a year ago, also includes voluntary certification of agribusiness retailers by a third party auditor to verify they are delivering recommendations and services consistent with the program's principles.

"The (American) program has fairly challenging criteria that have to be met in terms of record-keeping and application practices that they need to follow," says Tom Bruulsema, director of the International Plant Nutrition Institute's North America program's northeastern region. The institute represents the fertilizer industry.

Ontario pilot
Grain Farmers of Ontario, Ontario Agri Business Association and the Canadian Fertilizer Institute have implemented the Ontario pilot, which involves assigning an agronomist to work with the farmers to apply the four Rs.

Crosby Devitt, Grain Farmers vice-president for strategic development, says the goal is improvement from both environmental and productivity perspectives.

The groups will review the results of the pilot and determine what are the next steps. They have also begun to explore the possibility of establishing a memorandum of understanding with the province in connection with the program. Devitt says the talks are very preliminary and positions have not yet been formed.

Is all this activity enough, however, to deliver the resources and knowledge Canada and the United States will need to meet their 2018 deadline for beginning to implement a bi-national management strategy for Lake Erie? Many researchers point out that, for every answer, there are still dozens of other questions.

Ivan O'Halloran is a University of Guelph associate professor who specializes in soil fertility and nutrient use efficiency and has been conducting research into tile drainage and phosphorus loss. He notes that, while understanding is evolving on how to mitigate phosphorus loss at the end of a tile line, questions such as how often the tile water would need to be treated, how much of it is coming out and what are the interrelationships between soil type and management system "are ones we're still trying to get a good handle on."

Other assumptions, he says, might need more scrutiny. For instance, banding phosphorus is usually seen as a best practice, both to reduce phosphorus loss (compared to broadcasting it) and make it more available to the plant. But is banding as effective as is assumed on either front?

"Phosphorus has low solubility and there are many absorption sites or precipitation reactions that can occur in the soil," he says. "So when you band phosphorus in a localized zone of soil, you sort of saturate all those sites and you help saturate those reactions, which then allows phosphorus to stay in higher concentration in and around the fertilizer band."

Could all of that excess mean there is potential for greater losses in tile flow? The answer, he says, may be found in how the bands run in relationship to the tiles.

"So there's a whole bunch of other little questions that come into play, and you might be totally missing the impact of banding just because you happen to plant across your tile lines instead of up and down your tile lines."

For Keith Reid, a federal soil scientist, one of the big questions is what happens to that soluble reactive phosphorus when it leaves the field edge and travels to the edge of the stream. Often it's not travelling over agricultural land and "there are things that go on there that will have a great impact on the amount of phosphorus that actually reaches the stream, but we don't have that well accounted for."

That lack of knowledge is concerning for measuring interventions taking place in the farm field, he says. What happens if a farmer implements a best management practice but no "signal" of its effect is registered at the outlet to the watershed? Does that mean the practice wasn't effective, or that other sources are still there that "swamped" the signal, or is there a lag time?

"Those are huge questions as far as understanding what we need to be doing or what should be done on the landscape," he says.

Fragmented picture
Then there are the little mysteries that appear at every step of the nutrient cycle.

One time, at Taylor's farm, for example, when a moderate two-inch rain fell after a dry period, it triggered the researchers' sampling equipment. Three samples were taken and then the flow suddenly stopped. Taylor says they speculated worm castings in the earthworm channels swelled enough to block the flow to the tiles.

Andy Ward, a professor in the department of food, agricultural and biological engineering at Ohio State University, notes that research to date has turned up good results, but the picture it paints is fragmented. Because of all that is still not known, "we can't take the results and say, OK, if most of the farmers do this, they're going to get a 25 per cent or a 40 per cent or a 60 per cent reduction."

Each field and how it's managed is different; that means solutions are going to be specific, too.

What's needed, Ward says, is a comprehensive systems approach – one that marries in-field, edge-of-field and in-stream site-specific solutions to reduce nutrient loss, tackles all forms of nutrients at once, and features approaches that are reasonable and practical to implement. But, to get to that point, more data about the performance of solutions need to be collected and shared.

"If we can't quantify the benefit, I don't know how we're ever going to solve the problem. And I think farmers need to see that it's working."

Last October, Ward and the University of Ohio, in conjunction with Greenleaf Advisors LLC, a Chicago-based sustainability consulting firm, as well as Antioch College, brought together researchers, industry representatives and farmers in Columbus Ohio to share information and come up with practical, measurable approaches to nutrient management. The workshop featured presentations from experts involved in 16 case studies of areas of different scales within the Great Lakes and Mississippi River watersheds (including the research being done in the southern Ontario's Thames River watershed). Ward hopes a symposium will be held this year to provide updates on the case studies.

Governments have been throwing money at the problem, such as offering funding to farmers for environmental improvements, he says. But the programs don't ensure the practices are implemented where they're needed the most, and don't ensure all farmers become involved. "It's just a random sign-up process."

Yet regulation, such as that passed in Ohio last year requiring anyone who applies commercial fertilizer to undergo training (it takes effect in 2017) or the other restrictions on fertilizer applications currently being considered by the state, is not the answer either.

Legislation might make it difficult for farmers to farm some years and, worse, "there's actually no knowledge base to support the (Ohio-proposed) legislation," Ward says. Such approaches to regulate farmers' activities will only create distrust between government agencies, regulators and the farming community, he warns.

Here in Ontario, the provincial government was just beginning to formulate its phosphorus reduction strategy in agriculture in January, and so it was too early in the process to determine whether regulation will play a role.

Nevertheless, for the farm community, regulation has been the elephant in the room ever since the province's decision to introduce controls over the use of neonicotinoid seed treatments, implicated in honey bee poisonings.

"The style of how these regulations are coming into play, that does concern us, absolutely," says Barry Senft, Grain Farmers CEO. That's why, he says, Grain Farmers and several other commodity organizations in the province formed the Farm Action Now task force, whose goal was described in its November launch press release as developing a "farmer-driven, science-based blueprint" for the future of agriculture in the province.

Ontario Agriculture Minister Jeff Leal says, in an interview in late January, that the province will "continue to take a balanced precautionary approach." (The statement is almost identical to one he issued on the province's approach to proposed neonicotinoid regulation after the public comment period closed.)

The agricultural industry, he adds, is a key economic driver and farmers have proved themselves to be leaders in environmental stewardship. "I will continue to advocate for them each and every day, whether it's this issue or any other issue that is of critical importance to them."

At the same time, he says, water quality is of great importance to both urban and rural populations.

The ministry and Ohio's department of agriculture are leading the agricultural task team for the bi-national Great Lakes Water Quality Agreement, and Leal anticipates the advances the province's agricultural community has made in nutrient management will be shared with other farm communities around the Great Lakes through this connection.

"We need to move forward collectively on this issue," he says.

By early February, the Ontario and Canadian governments had rolled out a four year, $16 million Great Lakes agricultural stewardship program to help farmers introduce best management practices as well as to support technical training for service providers and educational outreach initiatives including demonstration farms. The Ontario Soil and Crop Improvement Association is delivering the program.

For now, it appears governments north of the border favour the carrot over the stick. Such an approach makes sense to farmers like Taylor, who points out if there eventually is regulatory change farmers don't like, "it had better be based on good science, because somebody's going to challenge it." He's optimistic that good science is the goal embraced by all of those tackling on-farm phosphorus loss, but points out work on the problem is only in its infancy.

Taylor says he chaired the first soils conservation conference held in Ontario in the early 1980s. One conference-goer, he recalls, asserted what was really needed in the province's farm community was a conservation ethic.

"I think it's coming," Taylor says, 35 years later. "If we could have the science and show we can solve the problem without guys having to make too many changes, then maybe it doesn't matter." BF