Pulse Beat Individual Articles

The Pursuit of a soybean Variety as Adaptable as a Manitoban

By Toban Dyck, farmer and writer

YOU AND I, we’re good at some things. I can perform Walk the Dog with a yo-yo, for example.

But I am not good at predicting whether we should focus on soybeans tolerant of drought or excess moisture. Farmers, the ag industry, and plant breeders want soybean varieties that are drought tolerant when the late-season rains don’t come. The same bunch – of which I include myself – want soybean varieties that can handle excess moisture when we see our beans sitting in puddles for extended periods.

We may be talking about this all wrong. We may not actually want a variety that can do one or two things very well. What we want, more likely than not, are plant varieties that are able to adapt to various conditions, and plant varieties that can do many things well.

Breeding adaptability and versatility into soybean the varieties that Manitoba farmers have access to is no easy task, and it involves attention to detail at every stage along the innovation pipeline of bringing a new crop to market.

“Now what we’re not breeding for – and it’s likely because we haven’t had to – is varieties that are capable of changing,” says Malcolm Morrison, an oilseed physiologist with Agriculture and Agri- Food Canada (AAFC). “A variety that one year can tolerate drought, the next year might have to tolerate flooding.”

Morrison cites the increasing and more severe manifestations of climate change as the basis for plant breeding efforts to focus on developing plant varieties that can sense and interpret environmental cues and adapt to them.

As Manitoba works to find and secure its unique identity as a soybean-growing province, it should take seriously the plant breeding challenges scientists are committed to identifying and meeting.

“Farmers are going to see hot, dry conditions one year,” says Morrison. “And, you know, the following year, abundant moisture and flooding in the spring. We have to build into our varieties more resilience than we’re doing now. But, it’s not an easy thing to do. It requires that one can model the crop to address the question, for example, when – if there’s a prolonged period of moisture stress – does that occur and what is it likely going to affect? I would say that we need people that can look at models and then physiologists that can see how environment interacts with the genetics.”

The lack of adaptable varieties is a barrier to Manitoba or, more generally, Western Canada reaching a watershed, breakthrough moment in its soybean- production trajectory, but it is one hurdle of many.

One of the common misconceptions in Manitoba is that the province is situated on the northern threshold of soybean- growing potential. This, however, is not the case, according to Kevin Baron, a research scientist with Solum Valley Biosciences and a partner in N49 Genetics.

“People think we’re pushing the northern frontier of where soybeans can be grown,” says Baron. “But soybeans are actually grown in Siberia, Northern China and Sweden, a few places further north from a latitude perspective.”

Another hurdle is the way variety traits are being communicated to farmers. Growers may already have access to seed with increased levels of stress tolerance. They are just not being told about them.

“I do believe there is stress tolerance – hidden stress tolerance – in the germplasm growers have now. We just need to characterize it better,” says Baron. “We get Iron deficiency chlorosis (IDC), but I don’t think there’s anything else communicated to growers at this point about a variety’s tolerance to drought, salinity stress, or excess moisture. We could be giving growers information that there is material [varieties] out there that by happenstance has stress tolerance genes.”

Where breeders have accessed and screened germplasm is also a consideration to take seriously. As Baron points out, and this has been written about in previous issues of Pulse Beat, soybean research relevant to regions of Manitoba has been done in the U.S. on IDC-prone soils similar to our own.

Some of this research has led to the development of varieties with strong IDC tolerance , and some of these traits have been available in the north central US market for up to 40 years.

“If multinationals such as Syngenta, Pioneer (Corteva), or Bayer, evaluated material from their Minnesota or Iowa testing programs a little further north, they would probably be at a strategic advantage here with respect to IDC,” says Baron. “Regarding drought tolerance, you could look to breeding programs in Arkansas or North Carolina for experience on drought and water use efficiency traits in soybean. In several cases, researchers in these geographies establish field trials in sandy, drought-prone soil to evaluate soybean lines and nitrogen fixation, and this is an approach that could be adopted locally.”

Baron’s company is about five years out from bringing a new soybean variety to market, and it is doing so by subjecting lines to a series of managed stress environments. Using both field trials and indoor growth rooms to mimic Manitoba growing conditions, Baron’s company identifies the most stress tolerant material. “Every year, we can go into a growth room after sampling soil from these ugly ‘stressful’ field sites with IDC or salinity issues and use that to make genetic gains outside of the Manitoba growing season. If the environments are controlled or managed to generate severe stress, then the selection intensity is high and we can see differences amongst lines, selecting only the top performers,” he says. “And that’s how they’re able to keep making genetic progress. When mother nature doesn’t provide us with an annual, regular, and repeatable stress test, we intervene to make sure the selection pressure is there.”

Soybean yields were spotty in 2023, the result of a multitude of factors. Farmers are used to characterizing the yield discrepancies they see across their farms in terms of rainfall, but it’s more than that. Like many things, the devil appears in the details.

Some research out of the U.S. suggests that planting soybeans earlier, achieving rapid row closure, and extending the period for root systems to develop could be an effective way of ensuring the plant has moisture when it needs it and isn’t as reliant on the mid- to late-season rains Manitoba farmers have grown accustomed to.

Root systems can play an important, incremental role in a soybean plant’s ability to endure stress. According to Baron, the exploratory nature of varieties with fibrous root systems may allow them to extract more moisture from the topsoil earlier in the growing season.

“Some of them have a deeper rooting depth,” adds Baron. “So that when a mid- season drought comes along, they’re already accessing more water.”

There is no silver bullet when it comes to the development of the perfect soybean variety for Manitoba and/or Western Canada. Baron confirms this in our interview. He is in the throes of the breeding process, and he shared three areas of focus in their variety development program:

1.Getting it right – finding the right combination of genes for yield and maturity that fits the target geography. Focusing on Manitoba soils and the stress tolerance of belowground processes that limit yield potential on marginal soils, cold and wet soils, or in response to drought, salinity, or IDC.

2.Root systems – developing a good root system early in the season and pairing this trait with supporting traits that enable soybeans to “beat the heat” during hot and dry spells. For example, selecting lines capable of accessing soil moisture deeper in the profile but also possess canopy wilt traits to conserve moisture and avoid defensive leaf flipping.

3.Nitrogen fixation – for yield and protein production, being cognizant of the relationship between nitrogen fixation, photosynthesis, and overall plant performance and plasticity under favourable and stressful environmental conditions. In pairing varieties with inoculant strains or formulations, are we selecting the best combination to perform under multiple scenarios?

“There are many variables to consider,” says Baron. “It’s a matter of managing them as best you can and paying attention to the details most important to your commercial field or target environment.”

Manitoba is on the right path. It’s a province still relatively new to the soybean market, and it is still finding its footing in it. Rest assured, with minds like Baron’s and Morrison’s and the work MPSG is doing on its own, with collaborating researchers, and with its sister organizations like Soy Canada, Manitoba will find its place in the global market. The potential seems far from tapped and the incremental gains researchers are making could and should be celebrated.