Use on-farm trials for informed decision-making

Use on-farm trials for informed decision-making


  • On-farm trials help answer agronomic questions
  • Technology makes it easy to conduct trials on your own farm
  • Using a small test area can still give accurate results
  • Turn your top production and planning questions into replicated trials

Whether you grow corn, canola, forage crops or vegetables, you likely have unanswered agronomic questions – questions that properly designed on-farm trials might answer. But you need to do the trials properly and follow through, or it’s likely to be a waste of time.

Would a fungicide application increase yield and preserve crop quality? What’s the optimum seeding rate for this crop? Does granular inoculant perform better than peat inoculant applied to the seed? What about that brand new foliar fertilizer?

Each company wants to shine the best possible light on its products, so company information has to be taken with a grain of salt.

On his farm near Carman, Man., Brent VanKoughnet of Agri Skills does field-scale trials for various companies as well as trials to satisfy his own curiosity. He’s a big advocate of producers doing the work to reach conclusions for their own farms.

It has never been easier to plan on-farm trials and harvest meaningful data.

“What in management planning drives you crazy? What do I need to do to be smarter in the next production season?” VanKoughnet asks. He advises producers to turn their top questions into replicated trials.

In Ontario, Peter Johnson has spent his entire career challenging farmers to prove him right or wrong on their own farms. After many years as the wheat lead with Ontario Ministry of Agriculture, Food and Rural Affairs and now as the resident agronomist with, Johnson is convinced it has never been easier to plan on-farm trials and harvest meaningful data.

“It drives me nuts when I hear farmers or see tweets that announce huge yield differences resulting from field-to-field comparisons that aren’t valid. We shouldn’t be making major decisions based on poorly designed or random comparisons,” Johnson says. “We can do better.”

Technology makes it easy

“A well-calibrated yield monitor essentially turns a farm into a research centre, but farmers have to set up the project properly to get anything useful out of it,” Johnson says. “It’s not about splitting a field in half or comparing one whole field to another. It’s all about replication, and with RTK auto steer and accurate yield monitors it’s much easier today than in the past to do it right.”

For his part, VanKoughnet prefers to back up yield monitor data with weigh wagons, and fortunately more grain carts now come with weigh systems. As well, regular GPS auto steer without RTK can be adequate if the combine header is narrower than the seeder or sprayer.

Both researchers say the secret is replications; at least three or four per location. By using A-B lines on GPS guidance, it’s possible to do each treatment separately. For example, one treatment would be done first on A-B strips 12, 15 and 18. The rate or treatment is adjusted and applied on strips 13, 16 and 19. The third treatment goes on strips 14, 17 and 20. This creates a trial that is easy, but generates more meaningful results than splitting the field into thirds for each treatment.

Field strips versus plot trials

Most research is done in small plots with numerous replications. While that approach has advantages, VanKoughnet believes long skinny strips running the length of the field help incorporate and manage variability. However, care should be taken to avoid old field edges and fence lines. Wheel tracks from other operations can also skew results. You need to build trials with approaches that remove potential bias.

“If you have a three- or four-bushel-per-acre improvement it may seem small, but if it’s stable across all replicates, it’s real,” VanKoughnet says. “A big yield improvement on just one strip might not be.”

Johnson is a big believer in collaborative learning. “Find four or five other farmers in your area and have everyone follow the same trial plan and share the data at the end of the year. The Iowa Soybean Association on-farm network posts suggested trials on their website, and they often get over 100 producers who will follow through and share the results. That is powerful.”

The Manitoba Pulse & Soybean Growers Association has a similar approach with its on-farm network. Producers can participate in specific trials, with established protocols organized by a dedicated research partner.

Test your precision ag prescription

An increasing number of growers are working with agronomic companies to apply variable rates of fertilizer and sometimes seed. Soil tests, aerial photographs and topographical maps are among the factors used to build the variable rate prescriptions.

VanKoughnet recommends replicated trials to test whether the variable rate prescription is actually making you money. Just do strips with your non-variable regular rate of fertilizer or seed and compare them to adjacent strips that use the prescribed variable rate. 

“I’d recommend going with a company that has a verification strategy,” VanKoughnet advises. “Why invest in a technology unless there’s proof?”

From an AgriSuccess article (March 2016) by Peter Gredig and Kevin Hursh