When Nitrogen Pays Back

Friday, October 30, 2026

On-farm trials found yield gains, lower emissions & strong returns

By Emily McKinlay

Since 2021, Agriculture and Agri-Food Canada’s (AAFC) Agricultural Climate Solutions Living Labs Program has brought farmers, researchers and other industry partners together to develop and test best management practices.

With the Ontario Soil and Crop Improvement Association (OSCIA) as a lead partner, the Ontario Living Labs Program has worked with nearly 50 farms to research nitrogen management, cover-crop grazing, manure storage management, and pollinator habitat management.

As the program approaches the end of its funding in 2028, Better Farming spoke with researchers and farmer cooperators in the nitrogen management project about the value that onfarm research has brought to their operation and the industry.

The project

The nitrogen management study, led by AAFC’s Dr. David Pelster and Dr. Craig Drury, explored the use of nitrogen inhibitors at typical and reduced nitrogen fertilizer application rates on corn crops. The team measured yield and nitrous oxide emissions as indicators of nitrogen-use efficiency.

“Essentially, we were trying to improve nitrogen fertilizer management to increase crop production and nitrogen-use efficiency, while decreasing environmental losses through nitrous oxide emissions and ammonia volatilization,” says Drury.

“We do a fair bit of intensive research on this topic on university- or government- owned farms, but we are somewhat restricted on the soils and associated climates that are available to us for this intensive research. Conducting research on grower fields allows us to evaluate the more promising treatments on different soils and different farming operations.”

Drury says this also equips producers with the skills and knowledge to continue to test out new management practices for themselves, which many of the collaborating farmers already have experience with.

“As a farm, we do a lot of research and nearly every field has trials occurring in it,” says Norm Lamothe of Woodleigh Farms near Peterborough.

“We are ultimately a research farm, and I spend a lot of time setting up trials.”

Lamothe says that the largest labour commitment for the Living Labs project was setting up the plots.

“There were four treatments with three repetitions for a total of 12 plots in the field. It could be tricky to sidedress the corn with the correct products and nitrogen rates, but once the corn was at the six-leaf stage, it was hands-off for me until we collected yield data.”

Jennifer Doelman, who owns Bonnechere Haven Farms in Renfrew County, says that while the first year on the study took some adjustments, the project overall has been relatively uncomplicated.

“The research used naked nitrogen fertilizer or fertilizer with inhibitors as the treatments, and you applied those at your normal rates or at a 15 per cent reduction from your typical rates,” says Doelman.

“It has been quite painless, especially when we had someone at OSCIA helping to compile everything. The first year I was in the fertilizer spreader trying to figure everything out, but the next I just set out flags, and it was really fast.”

Marion Hofhuis, farm manager at Osgoode Farms in Osgoode, says that field space was one more major consideration for the project.

“Strip-tilling is our first pass across the field and lays the foundation for the plot. Getting the right products and rates down was our most important task in the spring, while fitting in the 12 repetitions at 40 feet made field selection a bit more challenging.”

Results & variability

On-farm research broadens the range of soils and climates available to researchers but also introduces greater variability within and between farms.

“There are two aspects to consider when comparing data within and between farms. One is the equipment available on each farm, as well as the adoption of 4R practices,” says Drury.

“The second is the type of soil and the variability in soil properties across the farmers’ fields. In a given field, soil texture may be different in one end of the field versus the rest of the field. We randomize our treatments to ensure that field variability doesn’t mask the results so that we can evaluate the treatments more objectively.”

The practice of having 12 strip plots — three replicates of each of four treatments — is one way to account for field variability.

Pelster says the variability across farms could improve the study’s robustness under field conditions.

“Variability is just an artifact and something you have to manage.

“When we are starting to see trends despite the variability, it shows we are on the right track. It may make the conclusions less strong, but if we are starting to see trends across that variability, I think it makes for a more robust study in the end.”

Pelster says that Drury has observed clearer results on the farms in Southern Ontario than Pelster has in Eastern Ontario.

“The first two years of results for one farm in the Harrow region found on average an eight-bushel increase in yield when using inhibitors at their regular application rate of 180 lb of nitrogen per acre. They found a nine-bushel increase when using the inhibitors at the lower application rate of 155 lbs of nitrogen per acre,” says Drury.

“They were able to reduce losses and keep more nitrogen in the soil, which went toward increasing crop yields. Another farm near Ilderton had a five- to 10-bushel-per-acre increase at an application rate of 190 lb of nitrogen per acre when inhibitors were applied.”

Nitrous oxide emissions weren’t measured at all farms due to the labour intensity of data collection, but Drury still found some interesting results.

“In the first year, we measured a 41 per cent reduction in nitrous oxide emissions at the typical nitrogen fertilizer application rate of 180 lb of nitrogen per acre when inhibitors were applied. We saw a 61 per cent reduction in nitrous oxide emissions when nitrogen fertilizer was applied at the reduced rate and 68 per cent reduction when combined with inhibitors,” says Drury.

“Seeing the reduced nitrous oxide losses when inhibitors were applied is good from an environmental standpoint. We didn’t always see yield benefits, but there were clear advantages of adopting improved nitrogen management strategies.” Lamothe says he is very sensitive to profitability in his operation and still found returns.

“I hold a tight pencil and don’t over-apply nitrogen as a rule. You typically get increased emissions if you over-apply. By reducing nitrogen application rates and using an inhibitor, we were still seeing an economic benefit of using that inhibitor.

“We saw a 2:1 return on investment on the reduced rate with the inhibitor and still ended up with the same or higher yield. We saw a 3:1 to 4:1 return on investment on using the inhibitor at the higher application rates, which also tells us we were not using enough nitrogen to begin with.”

End goals & industry value

Beyond validating proposed best management practices, on-farm research has provided additional benefits to researchers and farmers.

Doelman adds, “We live in Renfrew County. We are nowhere near a research station. Our neighbourhood has its own microclimate, which is quite different from the nearest research station’s.”

The results could also be referenced during the development of ag-related policy.

“We want to see this kind of research, so when we get pressure from policymakers, we can make sure these best management practices actually solve the problem,” says Doelman

Hofhuis adds, “This nitrogen emissions project is relevant to current discussions in policy around potential nitrogen caps. This research directly ties to that and can be used in those discussions.”

The collaborative aspect has also been beneficial for trying new practices on the farm. This can support knowledge transfer efforts by the researchers, ensuring more producers have access to information about new management practices.

Pelster says, “The work we do on research farms and the central experimental farm is not as valuable unless it gets out to farmers. Having them involved is an easier way to spread that knowledge to the farm. Other farmers are more likely to talk to their neighbours than call me up.”

Collaboration promotes more open communication, and researchers can develop future projects from the concerns and challenges brought to them by producers. It also gives farmers the tools and experience to conduct more on-farm research for themselves.

Lamothe says the research is also an opportunity to look at the economics behind new practices.

“It gives me the ability to validate some predispositions we have as producers related to whether a practice is working or not. Until you attach a research approach to the practice, it is hard to share with others.

“I’m always looking through an economic lens when trying new products or different practices, and the research component helps validate that practice.

“In our case, the nitrogen quantity has really popped out as something we need to take a look at and adjust to get economic returns.”

Pelster says improving economics for farmers is the basis for crop research, specifically around nitrogen- use efficiency.

“If producers are reducing their nitrogen losses, they are going to be improving nitrogen-use efficiency, and with that hopefully they can have better or similar yields with lower input costs,” says Pelster.

“In the end, it’s the bottom line that counts. We are seeing co-benefits, reduced emissions, and better nitrogen- use efficiency. Hopefully we can all win that way.” BF