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5 Steps to Grow High-Yield Soybeans
If crops were pro football players, corn would be the all-pro quarterback, while soybeans would be the benchwarmers. Typically, corn receives all the glory, while soybeans are shunted aside.
It doesn’t have to be that way. “Put some effort into them!” says Joel Wipperfurth, a WinField United ag technology applications lead. With proper management, soybeans can brim bins with plentiful yields as does corn.
That’s the approach that Dan Arkels of Peru, Illinois, takes. In 2014, he won the Illinois Soybean Association yield contest with a 104-bushel-per-acre yield.
“That year, my normal production soybeans averaged 70 bushels (per acre),” he says. “So, I drew a line between what I spent on growing 70-bushel beans and 104-bushel beans.”
He sold soybeans at around $10 per bushel that year, which enabled him to glean an extra $340 per acre in gross revenues on the 30-acre plot of contest soybeans. The extra $340 in gross revenues he gleaned dwarfed the money he spent on inputs to glean the extra 34-bushel-per-acre yield.
Granted, much still hinges on the weather. A droughty August can nix some of the extra input and strategy benefits.
“If you have a good stretch of weather that will take beans the distance, it’s worth spending money on them,” says Arkels.
Here are five of the steps Arkels takes to aim for high soybean yields.
“My soils are black, tight, and deep Muscatine-Sable type of soils,” he says. This makes for excellent water-holding capacity, although drainage is a must.
“I always try to put contest beans on well-drained fields, because drainage is a big part of high yields,” he says. Well-drained soils enable soybeans to start well and deter diseases.
2. Variety selection
“When I look at variety selection, the most important thing to me is plant health,” he says. “I look at resistance to SCN (soybean cyst nematode), SDS (sudden death syndrome), and white mold.
“I also look at full-season products for my area,” he says. On contest beans, he’s planted maturity group 3.4 soybeans. By flowering late into the season, more pods and potentially higher yields result, he says.
3. Early planting
Aiming to plant soybeans early in mid-April leverages the increased flowering period that full-season varieties have. “A soybean plant is light-sensitive, and it will flower as late as the season allows,” he says.
4. Supply nitrogen.
“I feel a soybean plant is able to fix its own nitrogen (N) right up to 80 bushels per acre in my area,” Arkels says. “If you want to grow over 80-bushel beans, you have to provide soybeans some form of nitrogen.”
He normally combines 50 pounds per acre of 32% N and an N inhibitor with a preplant herbicide. Soybeans often go through a two- to three-week “ugly” phase early in the season, where they are yellowed and stunted. The weed-and-feed application helps plants nix the ugly phase and develop an excellent root system packed with N-fixing nodules, he says.
After that, all N is foliar-applied, with contest soybeans receiving at least two foliar applications of N. Multiple applications of a fungicide are also key, he says. In contest fields, he will apply up to three fungicide applications during the reproductive phase, which are often combined with foliar N.
Conventional soybean fields typically don’t receive as many applications, but the concept remains. “The N feeds the plant, while the fungicide keeps the plant healthy,” says Arkels. “If you can’t keep a plant healthy, it will not produce.”
Sufficient potassium (K) levels are also needed. “Demand for potash in soybeans is astronomically high in a high-yield environment,” Arkels says.
Foliar applications are keyed by tissue tests. “I send tissue tests to the lab, and the report tells me if I’m short on N, P (phosphorus), K, and micronutrients,” he says. This allows Arkels the opportunity to correct deficiencies, mainly K and micronutrients like boron, copper, manganese and magnesium.
5. Weed management
Using residual preemergence herbicides is key. “It’s amazing what a good job a pre can do managing weeds,” says Arkels. “That is the biggest answer for managing resistant weeds. A pre holds weeds back until I come back with a postemergence herbicide.”
Slashing seedbank weeds is also key, says Wipperfurth. He says 50% of waterhemp seeds are viable nine days after flowering. Rouging and removing waterhemp plants from a field before harvest prevents weed seeds from sprouting in future years.
Learning From Yield Contests
Intensive soybean management has drawbacks. “Steps taken to increase yields (such as using high fertility and plant hormones) create a lot of growth that makes soybeans prone to lodging,” says Arkels.
In 2016, Arkels estimated he had 130-bushel-per-acre soybean contest yields on the way, with lush 5- to 6-foot-high soybeans soaking up sunlight. However, a straight-line summer wind lodged them.
“They were so heavy with pods that they couldn’t upright themselves after the storm,” he says. “That cost me up to 35 bushels (per acre) in yield.”
Ideally, Arkels would like a bushier bean plant, rather than one that grows so tall. He’s been working with a company called Biovante that’s testing a foliar growth regulator aimed at making soybeans shorter and pushing internodes closer together.
“This makes them more of a bush plant, one that’s shorter and wider,” he says. Results are promising on his on-farm tests, he says.
Reality has a way of snapping back when it comes to taking contest practices across the farm. All soils aren’t going to be rich, black ones, and all intensive practices aren't going to pay.
Still, Arkels advises taking contest lessons learned and applying them across the rest of the farm. Some steps, such as early planting, can be used with no extra inputs.
“We are all struggling to make a dollar these days,” notes Arkels. “One way to make ends meet is to grow more bushels.”
By Gil Gullickson