Polycropping soybeans and winter cereals

Ryan Boyd discusses his experiment interseeding winter wheat with soybeans during a June 29 field tour at his operation north of Forrest, Man.

Ryan Boyd says an RTK guidance system is his first, but not his last foray into precision agriculture

Ryan Boyd is hoping winter cereals and soybeans will be a match made in polycrops heaven.

The Forrest-area producer has previously experimented with cover crops and mob grazing in order to increase soil organic matter and infiltration, but this year has turned his gaze to precision agriculture. His operation was the focus of a June 29 field tour, organized by the Manitoba Forage and Grassland Association Grazing Club and sponsored by Ducks Unlimited.

Boyd broke in his RTK field guidance system this year with oats, spring wheat and winter wheat interseeded with soybeans in 15-inch rows.

“All three I see potential in, but the winter wheat, I like the looks of it with the beans between,” Boyd said. “For growing a crop of soybeans, you could spray the wheat out at herbicide timing on the soybeans and then the soybeans continue to harvest. I like the looks of that, but I also think there’s potential to grow a relay crop of forage underseeded under the winter wheat on the wide rows as well. So you harvest the winter wheat and let the forage grow after harvest and graze that late in the fall.”

The $15,000-per-machine RTK investment is one of the first steps in what Boyd says will eventually be a controlled traffic system, where equipment runs down tram lines. The system is meant to limit wheel compaction to a designated path, leaving most of the field untravelled.

“We’re still learning there. I didn’t have things set just exact so it wasn’t perfect,” Boyd said.

“I’m not sure that it needs to be RTK though. You could do the same thing on a slight angle and it would probably accomplish the same results without the investment in RTK.

Polycrops have been cited as a method to increase biodiversity and jump-start organic matter, but Boyd says he is also looking at their effect on water in the field.

He has started to use winter wheat as a water management tool, he said, noting that the crop will suck up excess moisture before soybeans are planted.

Should the soil start to dry out, he said, the cereals can then be sprayed out, while soybeans continue to grow.

Early-emerging cereals further limited wind erosion and acted as weed control, Boyd said, while both oats and winter wheat created a warmer, less windy microclimate that was conducive to growth.

“The beans don’t appear to have suffered at all in that system up to now. The crop has given them enough room to grow,” he said.

The June 29 event had two purposes for Michael Thiele, Ducks Unlimited grazing club co-ordinator. A vocal advocate of cover and polycrops, Thiele said he hoped to promote soil health, while also pitching the merits of winter wheat and cereals.

Winter wheat has been in decline in Manitoba since at least 2013. Just over 140,000 acres were seeded to the crop in 2016, according to the March Statistics Canada seeding expectations report. In fall 2012, winter wheat totalled just less than 600,000 acres.

At the same time, soybeans have been on the rise. Soybean acres were expected to increase by over 34 per cent to 2.2 million acres in Manitoba this year, the biggest increase of any province.

“Everybody wants to grow soybeans. Everybody’s doubling down this year on soybeans, but what could be even more interesting than growing soybeans is to grow them with winter wheat. Suddenly, guess what, you can harvest three crops in two years,” Thiele said.

The day was not without challenges. When asked whether his cover cropping may, in fact, dry out soil, Boyd acknowledged that the crops drew out more water, but refuted the suggestion that the system might cause problems should weather return to the much drier conditions common in the area decades ago.

“When it happens here, we’ll adjust,” he said.

Thiele responded by pointing to research that says cover crops and polycrops increase moisture retention in the long term as organic matter increases.

“We have the data to show that is absolutely not correct, but that’s not what guys understand,” Thiele said. “They have this sort of simplistic idea that you grow something, you dry the soil out. That’s actually true in a degraded soil, because you’re not storing moisture, but as soon as you start rebuilding that soil by growing cover crops, you’re actually capable of holding more moisture.”

The Food and Agriculture Organization of the United Nations estimates that a one per cent increase in soil organic matter will increase available water-holding capacity in by 3.7 per cent, using an oft-quoted 1994 study by Berman Hudson.

Thiele admitted that there will be a learning curve to Boyd’s system of intercropping and precision agriculture, as well as investment. A producer must have the right seeder and, likely, expensive RTK guidance systems. Likewise, the concept of harvesting an upper crop while leaving an underseeded crop to grow causes its on logistical complications.

“You’re adding complexity, so sure there’s issues, but we just have to learn how to do it, because there’s good reasons to do this stuff,” he said. “That soybean’s actually doing nicer under that winter wheat canopy because you’ve created a nice microclimate. It’s warmer. The wind, when it’s been howling, doesn’t beat that poor little soybean that’s totally exposed.”

Results of the experimental crop mix won’t be known until later this year.

About the author


Alexis Stockford

Alexis Stockford is a journalist and photographer with the Manitoba Co-operator. She previously reported with the Morden Times and was news editor of  campus newspaper, The Omega, at Thompson Rivers University in Kamloops, BC. She grew up on a mixed farm near Miami, Man.



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