Colin Rosengren knows how to grab his audience’s attention.
During his PowerPoint presentation on intercropping at Ag Days in Brandon Jan. 21, Rosengren brought up a slide called “show me the money.”
It illustrated how in 2008, when growing peas and canola together on his farm near Midale, Sask., he earned a net profit of $267 per acre. In stark comparison, growing canola alone on his farm in 2008 returned a profit of $82 per acre.
“This (intercropping) is the only thing at the show that will increase yield without costing you dollars,” said Rosengren, who farms 4,500 acres.
Read Also
VIDEO: Green Lightning and Nytro Ag win sustainability innovation award
Nytro Ag Corp and Green Lightning recieved an innovation award at Ag in Motion 2025 for the Green Lightning Nitrogen Machine, which converts atmospheric nitrogen into a plant-usable form.
“The economics are definitely there to make this system work.”
For the last five years, Rosengren has experimented with what he likes to call field husbandry, the lost art of working with nature to grow high yielding crops.
When practising mixed intercropping, farmers grow two crops on the same field with no row arrangement and harvest both at the same time. Using this system, Rosengren has grown pea-canola, flax-wheat, flax-lentil and chickpea-flax.
Pea-canola is his most successful combination, producing higher yields than either crop grown in monoculture.
“On average 20 percent extra yielding … and last year was even more, maybe 40 percent overyielding,” he said.
Rosengren said soil responds when plants are grown together as nature intended.
“Better utilization of resources …. We’re able to use moisture from different depths.”
Rosengren seeds in one pass with two carts, four compartments and openers with two depths. Having a legume like peas in the mix reduces the need for nitrogen, which reduces fertilizer inputs.
He was reluctant to provide specific nutrient level numbers because soil conditions vary greatly on the Prairies. He advised producers who are interested in intercropping to work with agronomists.
A commonly asked question is about spraying different crops in the same field, but Rosengren said the mixture of plants provides natural protection from disease and insects.
As an example, flea beetles prefer a monoculture to variety because, as an entomologist explained to Rosengren, beetles can count to four.
“If they find four host plants (in succession), they stay in the field.”
Consequently, Rosengren has cut his pesticide use and does mostly spot spraying as required.
He either straight combines or swaths his canola-pea crop.
“If you choose your varieties right … so the two end up near the same height, then it seems to stand quite well and has a pretty low risk of wind shattering, which allows you to straight cut it without much risk (of shattering).”
Once in the yard, Rosengren separates the crops with a $7,000 drum cleaner.
“It’s not nearly as tough as you might think,” he said.
Pat Neville, an organic pedigree seed grower from Govan, Sask., who already intercrops with oats and peas, said harvest time is the big problem.
“You’ve got to clean the peas and the oats as it’s combined. Otherwise, the oats will pick up the moisture of the peas,” said Neville. The Govan farmer says this step requires manpower that he doesn’t have.
Despite that problem, Neville was encouraged by Rosengren’s presentation and he hopes to overcome the logistical obstacle this year or next.
The complications of two crops, especially during the harvest time crunch, is one reason why more producers haven’t adopted intercropping, said Tony Szumigalski, a policy analyst with Manitoba Agriculture who did a PhD on intercropping at the University of Manitoba.
“It (intercropping) has been demonstrated to work … (but) it’s perceived to be a management hassle.”
Szumigalski said farmers might learn from the past and eventually adopt intercropping.
“When zero till was first coming out 25 years ago … it was the innovators who just went ahead and did it.”
Intercropping 101
- Seeding: Put in seeds as early as possible and place the canola at a shallower depth than the peas. This puts the canola into warmer soil and allows the oilseed to emerge earlier, which helps balance maturity at harvest time.
- Weeds & spraying: Early seeding helps the crop get a jump on broadleaf weeds. The combination of plants provides natural resistance to pests. Spot spray for wild oats.
- Harvest: Straight cutting will work, but a key is selecting varieties that end up at nearly the same height. The two crops then support each other, maintaining the stand and reducing wind shatter.
- Separation: Setting up a drum cleaner and augers to separate the crops into different bins takes time. Take the time to plan the harvest and maybe even perform a dry run to get the logistics right.
