50 Years of the Elora Management Trial

Thursday, August 27, 2026

Teamwork is key in the long-term studies

By Emily McKinlay

Dr. Adrian Correndo says that collaboration has been fundamental to the University of Guelph’s Elora Management Trial as it nears its 51st year of harvests.

The trial began in 1976 and has since expanded to examine three major crop management factors — tillage, rotation, and cover crops — and their interactions. Correndo has led the project since 2023 and is eager to continue the study’s long-standing history, which helps grain farmers make better crop management decisions.

The 1976 trial, now in its 51st growing season, was initiated to investigate the effect of tillage on soil health and productivity.

“The first topic, tillage, was started in 1976 by Dr. Terry Daynard, who is now retired. It was then led by Dr. Tony Vyn, who was a graduate student of Dr. Daynard at the time, until 1999. Then Dr. Bill Deen led the study from 2000 to 2020. In 2023, when I arrived at the university, I took over,” says Correndo.

The tillage component of the trial began with continuous corn plots until 1990, when it transitioned to a corn-soybean rotation.

“We have been testing 10 different tillage managements from no-till to mouldboard plows, chisel plows, cultivators, and discs. This study has been bringing together a lot of information on the impact on productivity and soil health and how different tillage systems change the distribution of carbon across soil profiles,” says Correndo.

The second aspect of the study, which started in 1980, investigated the impact of crop rotation.

“From the tillage trial, one of the main take-home messages was that when we are changing tillage strategies, we are actually trying to manage residue. Since our plots were in a constant rotation, it was decided to simplify and combine the tillage system with the residue on top,” explains Correndo.

“In this trial, the rotation is the main component, and tillage is the subplot. We have side-by-side plots within each big plot, which include a no-till and a chisel plow with a cultivator treatment. For rotations, we have continuous corn, continuous alfalfa, and corn with cereals and with or without red clover, which is our only cover crop. We also have the famous corn-soybean and corn-soybean-winter wheat rotations.”

The rotations studied in the trial emphasized the value of having year-round roots in the soil with the inclusion of a winter crop.

“Our rotation treatments brought up both answers and more questions — like what is the value of having a winter crop in the rotation? Or, in terms of regenerative agriculture practices, what is the best combination of crops to reduce the amount of tillage needed in the rotation while having roots in the ground all year round? The goal would be to try to minimize soil disturbance and maximize the presence of roots throughout the calendar year.”

This led to the creation of a third study in 2017, which investigates the use of cover crops, with subplots of nitrogen application, tillage, and rotation.

“We want to evaluate functional groups of cover crops. I like to call them service crops because they are not just covering soil, but could also be fixing nitrogen or some mixes, like radish groups, could be providing soil tillage.”

The cover crop plots include red clover, rye, oats, and a three-way and 10-way mix. One rotation includes cereal rye, but the remainder of the rotations would include the cover crop plot after winter wheat harvest. Nitrogen application plots would follow productivity after application to corn or the cover crop in the rotation.

“We are trying to understand the nitrogen dynamic, to increase sequestration of carbon and to store nitrogen in forms that are not released into the environment. That’s the key with nitrogen. You don’t want to apply nitrogen in a window of the year that is susceptible to losses,” says Correndo.

He adds that the nitrogen portion of the study was included to observe if application would produce more cover crop biomass.

The three studies in the Elora Management Trial require between 400 and 500 plots, which are managed by a team of students and researchers.

Across the three trials, the studies have yielded interesting results that can help grain farmers promote productivity, stability, and resilience in their crops.

“We have seen a lot of benefits of including winter wheat into a corn-soybean rotation. We have analyzed several perspectives to understand the main effects of having a winter crop in a rotation. We’ve looked at productivity and yield and the stability of that productivity,” says Correndo.

“When we are talking about yield in corn and soybeans, one of the main messages in an analysis by Dr. Amélie Gaudin (a professor at the University of California Davis and previous PhD student at the University of Guelph) was that most of the benefits of including winter wheat in a rotation are related to better yields when we have a drought. And this is only studying productivity.”

He explains that these benefits stem from improved soil dynamics due to organic matter contributed by winter wheat, which improves soil structure and water infiltration and supports biological and chemical processes. The long-term benefits continue to support corn and soybean production in the rotation.

“The benefits are a little smaller in years that are colder and wet, but the benefits are still there,” shares Correndo.

“We see the same benefit for yield stability. When we look at the variability and error across seasons, we see reduced variability. Inclusion of winter wheat in a rotation reduced the coefficient of variation from 20 per cent to less than 10 per cent. You not only get higher yields, but more stable yields as well.”

The long-term nature of the study helps producers make decisions about new practices on their farm without using several seasons to determine if it fits their operation.

“Do you have 20 spare years to invest in your farm to see if something works? The main value of long-term trials has to do with building a system over time.

“We have the benefit of the time variable. For example, you cannot change soil from one year to the next. It takes at least five or 10 years to understand where it’s going, and that’s the same for crop productivity. We can group years into high-production or low-production seasons, or hot-and dry or cool-and-wet seasons. We are mainly thinking about weather because it is so variable. It is hard to have the same management under different weather conditions.

“We are bringing the time factor to the table — time that farmers don’t have available to see how something works. You need to have a good number of years to evaluate these practices over time.”

Correndo’s research team is working to understand how different management decisions will affect crop productivity and soil health under various conditions and over consecutive seasons.

This was critical for the team’s findings on the benefits of winter wheat in the rotation. Multiple hot-and-dry or cold-and-wet years were needed to measure crop productivity stability across different conditions. Cover crops also require approximately a decade to generate data that can be used to make management decisions.

“Cover crops have been around for decades, but implementation exploded in the early 2000s. Before that, it was much less common. There are a lot of questions about cover crops that we are going to answer in the next five to 10 years,” predicts Correndo.

“This study is the most complex and is a big investment. In the years to come, we are going to have a lot of students analyzing this data.”

With nearly 50 years of data from a growing number of plots, teamwork and organization are critical to the trial. Correndo praises his predecessors’ organization for conducting research over the years and looks forward to continuing to improve the systems.

“I am trying to implement systems to standardize the process of storing data and have a technician managing this. There is always an effort to have a transition time for our technicians, with at least a year of overlap to train in a standard system. During the years the trial has been on, we have been training several generations of professionals for both academia and the private sector.

“We have standards in how we manage and store the data, and a semantics dictionary where we try to have a lot of definitions for details like the units we are using. There is a lot of documentation.”

These systems and standards help to foster collaboration both within the University of Guelph and outside of the institution.

“We have to have systems in place, and everyone who is new to the trial has to learn the system. We are working on developing more. When I started, some worked well and others we are trying to adapt.

“Having standard procedures helps to manage trials and data in a uniform way. We are working with Michelle Edwards (the Director of Agri-food Data Strategy at the University of Guelph) to create a dashboard to establish standards and uniform names to navigate data more easily. The expectation is that it will be a useful tool for sharing data in future. We have international collaborators asking for data, and we are trying to implement this dashboard to help us facilitate that collaboration.”

Collaboration between organizations also supports the continued funding and communication of the research.

The project is supported by the University of Guelph’s Ontario Agri-Food Innovation Alliance, OMAFA, and the research stations, which are owned by Agricultural Research and Innovation Ontario.

The trials have consulting committees with organizations and other stakeholders, including farmers.

“We have a network of North American and international collaborators. It’s also rare to have such institutional support,” says Correndo.

“The support we get from the Alliance and the interactive collaboration with OMAFA is key to these long-term trials. The key word to describe this study is collaboration.

“We all try to help each other and understand that we can do better if we work together.” BF