At the University of Minnesota, soybean breeders are looking far beyond the next harvest; they’re developing varieties that can withstand pests, push yields higher and meet new demands from renewable fuels. That also means breeding soybeans to contain higher oil content that traditional varieties today, an innovation that could cater to the possible new demand.
Aaron Lorenz, a professor of agronomy and plant genetics, has spent the past decade leading efforts to ensure farmers have tools that work today and decades down the road. Standing in a research plot near St. Paul, he gestures toward rows of soybeans that tell the story of decades of progress.
“In the front we have varieties released in the 1940s and 1950s,” Lorenz explains. “You can see that they’re falling down. They don’t have very many pods on them. They’re very tall and lanky — not very good agronomically.”
Those early varieties might have been cutting-edge at the time, but they pale in comparison to today’s resilient, high-yielding soybeans.
“On average, breeders have increased yield by about a half a bushel per year,” Lorenz says. “Right now, the varieties farmers are growing yield about two and a half times more than what their predecessors grew back in the 1940s and 1950s. On-farm yield has increased two-and-a-half to three times — and a big chunk of that has been due to breeding better varieties. It’s been a long, continual investment. Incremental, but over time it adds up to something much better.”
Battling a Hidden Threat: Soybean Cyst Nematode
Yield isn’t the only focus. Lorenz and his team are also taking on one of the most persistent, and invisible, enemies of soybean farmers: the soybean cyst nematode (SCN).
“Soybean cyst nematode is No. 1,” Lorenz says. “The main concern is that the current resistance most Minnesota farmers use comes from one single source that researchers discovered 40 or 50 years ago. It’s been used so long and so often that there’s now resistance breakdown occurring on the landscape. The nematodes are evolving to overcome our current source of resistance.”
That means farmers who believe they’re protected might not actually be, and once they discover thee issue, it’s often too late.
“A farmer may plant a resistant variety, thinking they have protection,” Lorenz explains, “but if the nematode population in their field has changed and overcome that resistance, they may be losing yield and not even know it. That’s why it’s good to get a soil test and rotate your sources of resistance.”
Lorenz says his breeding program is working to stay ahead of that curve, developing new varieties before the old ones lose their power.
“We’re working with projects with Minnesota Soybean and the United Soybean Board,” he says. “We’re not just discovering new sources of resistance; we’re breeding with different ones. We know which genes have good resistance for new SCN populations, and we’re getting those into elite varieties that farmers may want to grow.”
Some of those experimental lines are already showing promise.
“We’ve had some varieties that have done quite well,” Lorenz says. “They’re not quite ready for farmers to use right now, but we’re hopeful. Getting them into better varieties will eventually give us strong performers in the future.”
Breeding for New Markets: Renewable Diesel and High-Oil Soybeans
Beyond yield and pest resistance, Lorenz’s team is also thinking about how soybeans will fit into the future of energy. With renewable diesel demand growing, farmers are being asked to produce crops with higher oil content.
“We understand there’s a lot of potential future demand for renewable diesel, which is going to require a lot more oil,” Lorenz says. “We’d like to increase the oil content in soybeans, from around 22% to maybe closer to 30%, to make it a higher-oil crop and more valuable from that standpoint.”
That work started when the Minnesota Soybean Growers Association approached the university with a challenge: Breed soybeans that can meet the renewable fuel industry’s needs.
“We work very closely with those grower groups to identify target traits we should be working on,” Lorenz explains. “They have their ears closer to the ground. They can see what the industry needs better than we can and help direct our research. It’s been a very fruitful collaboration.”
He says it’s also possible soybeans looks more like canola, as a way to capture more of the oil content from every plant. But that research is just a hint of what may be to come.
Looking Ahead
From fields filled with the tall, spindly soybeans of the 1940s to test plots growing varieties rich in oil and nematode resistance, the University of Minnesota’s breeding program reflects decades of continuous innovation.
Each seed planted represents a future crop, and a future challenge, already being met by researchers like Lorenz and his team.
“As long as we continue the incremental progress of selecting and developing better varieties,” Lorenz says, “over the long term we’ll always have something that’s a lot better.”
