Crop Planning for Soybeans

Fitting soybeans into a rotation takes a lot of planning. Here are some thoughts from the production specialist for Manitoba.

By John Dietz

First comes plan, then comes plant. In the case of soybeans, planning needs to happen long before planting.

If in doubt, ask Manitoba Pulse and Soybean Growers (MPSG) production specialist Cassandra Tkachuk.

“There are a lot of experienced soybean growers now, especially in the Red River Valley, but I think the majority are still learning how to bring soybeans into the production cycle,” Tkachuk says.

The learning curve has moved quickly, in less than 20 years, from the first innovators who tried a hand at the American crop to early adopters to mainstream growers.

By 2017, more than 3,800 farms were represented by the MPSG, and more than 2.3 million acres of soybeans were planted – nearly as many acres as seen in major American farm states.

Soybeans were, and are, bringing benefits to Prairie growers in western Canada, starting with the Red River Valley growers in Manitoba and moving west now to trials in the Peace River region of Alberta and British Columbia.

Benefits include amazing weed control, lower costs for inputs and high-end profit per acre. Soybeans are forgiving when it comes to time of planting, they will flow through conventional air seeders, and there is now more choices for new short-season varieties.

It’s the “honeymoon phase” of soybean production for the Prairies, says the specialist.

“We haven’t been growing them long enough to have a lot of issues. For instance, the soybean cyst nematode is expected to arrive in the near future. Once we get that, rotations are going to get a lot more tricky,” she says.

All that, however, doesn’t mean it’s easy to fit soybeans into a crop rotation.

“There are a lot of questions on this topic,” she says. “For a first-time grower, the Soybean Production Guidelines fact sheet that we created and released this past spring would be the best place to start. It scratches the surface, from planting to harvest and storage. In two pages, it has all the basic things you need to know.”

It can be found under Production Resources [] on the MSPG website and contains basic agronomic recommendations for soybeans including field and variety selection, seeding, fertility, pest management, and harvest and storage. It was developed through collaboration between specialists and researchers from the University of Manitoba, Manitoba Agriculture, and Manitoba Pulse & Soybean Growers.

If a grower asks, Tkachuk is happy to field their questions. She also is likely to send them to the new production guide, then encourage them to read other material on the website for soybean growers and finally, sign up for The Bean Report.

The Bean Report is an independent, three-page newsletter distributed bi-weekly throughout the growing season. It offers the latest information on soybean and pulse crop agronomy and research.

A good start

Tkachuk says, “Getting your soybean crop off to a good start is number one. Multiple factors need to go right, including seeding rate, depth and date.”

For instance, even though seed is very expensive, growers need to use enough seed to achieve optimum plant populations.

And, as May days slip by, they need to keep an eye on the calendar. As with all crops, there is an optimum seeding range for each variety chosen.

Or, sometimes the seed can be planted too deep.

For the novice grower, narrow rows will typically have a little more yield potential than wide rows and will close the canopy faster. Soybeans are poor competitors against weeds of any type, she says.

It might seem that adding soybeans would be simple, but not really.

Tkachuk says the business of introducing any potentially-profitable new crop into the rotation is complex and requires homework. It’s a whole new system for the farm, and it interacts with all the existing systems of producing other crops.

The grower association still is studying and learning about rotations on behalf of growers.

“Right now, we encourage rotations of four years or more for greater biodiversity,” Tkachuk says. “One common rotation now is a soybean-cereal-canola-cereal rotation. This lets you increase your nutrients in your cereal years. Cereals are less sensitive to seed-placed fertilizer than canola or soybeans.”

Then, under nutrient considerations while bringing soybeans into a rotation, there’s the issue of budgeting and balancing phosphorus supply. In some cases, phosphorus levels need to be built up over time and ahead of the soybean crop.

“You could write a whole article just on how to fertilize your rotation with phosphorus. Research has shown a lack of response to phosphorus, even at low soil test P levels, but you want to be sure you’re not mining the soil,” she says.

In short, with careful planning, growers are successfully adding soybeans to the rotation. Happily, today’s newcomers to the crop now have lots of Manitoba-specific resources available.