Mother Nature may have a major say in how soybean yields shake out every year, but 2012 state yield contest winners found that variety choice and timely inputs are crucial to putting more bushels in the bin.
"The most important variable that’s key to high yields is variety selection," says Shawn Conley, University of Wisconsin Extension agronomy specialist, who helps coordinate the state's soybean yield contest. "Among last year's first-place (Wisconsin) winners, three of the four varieties planted were highlighted in the Wisconsin Soybean Variety Test Results. Their yields were the result of a combination of good management and favorable environments."
Bahr Farms, owned by Dale and Kevin Bahr, Belmont, Wis., was the top producer in southwest Wisconsin, with 82.6 bushels per acre. After two droughts and some hard lessons on spider mite damage, Kevin visited a neighbor who was a previous NCGA yield winner.
"We’d faced many production challenges. I wanted to pick his brain about fertility and varieties,” Bahr says. “With some adjustments, we were able to achieve 80-90 bushels per acre.”
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He found that getting the soybean crop off to a good and early start is crucial. The Bahrs plant no-till soybeans in 30-inch rows with a corn planter to move residue out of the way. They prefer to plant in April, and protect the seed with inoculants and root promoter to get good early growth before bloom and shaded rows by the end of June.
Fertility and micronutrients
"The other tip is to be on the high end of fertility with P and K. Soybeans like old fertilizer. Put it on a year ahead and give it time to break down in the soil," he says.
Bahr also scouts at least once a week for insects and other pests. He does his own spraying with a self-propelled sprayer, and includes micronutrients with herbicide and fungicide applications.
The micronutrients pay for themselves, he says. “We have field averages in the high 60s to 70 and get 80 bushels per acre on the sweet spots."
Micronutrients have also become a favored management strategy for Dan Arkels, Peru, Ill., who raises corn and soybeans along the Illinois River. He topped the Illinois soybean yield challenge in the 2012 drought with an average 80.16 bushels per acre, and has won in previous years, too. Arkels planted in 30-inch rows.
"I planted for the competition last year in a high fertility field. I decided to follow the same course of action with all of my soybeans this year,” Arkels says. “My beans were armpit-high and loaded with pods in June. They yielded extraordinarily well; 25 bushels more per acre than the rest of the area. It is absolutely cost-effective to use these products and gain 20-25 bushels."
He applied N to his soybeans: 75 pounds per acre split between preplant and sidedress. He believes the preplant application contributed to yield gains. He aerially applied a foliar-applied micronutrient mix called Harvest Maxx, which includes manganese, N, sulfur, boron and zinc; plus StollerUSA BioForge to enhance plant growth and yields.
"Last year was the first year I tried all of these products. You don't know until you try new things what might boost your yield," he says. "The days of one spray and you're done are over in soybeans. You need to work with a local crop adviser and be willing to try new products."
Seed treatment and spray applications
Multiple sprays also led to success for Arkansas early season soybean yield winner Martin Henry from Dumas. He had a seeding rate of 139,000 in an irrigated field and achieved a 94.9 per-bushel yield. Henry used a seed treatment, preplant and postemergent herbicide applications and two insecticide and fungicide applications in his 30-inch rows.
"The first thing you need to do is pick the right seed for your soil," says the corn, soybean and rice producer. "We used 100 lbs. per acre of urea on the soybeans as well, and decided to try two insecticide and fungicide applications instead of one as in the past.
"I doubled up on both to battle stink bugs and disease, which this year was frogeye leaf spot," Henry continues. "You also improve the quality of your crop with fungicide. My soybeans looked healthier and stayed green longer, which allowed me to delay harvest and pick up more bushels. We gained 8-10 bushels per acre with this strategy, which more than justified the cost. You have to keep an eye out for fungicide resistance, but we are trying three applications next."