6 Tips for Higher Soybean Yields

JEFFERSON CITY, Mo. (DTN) -- In 2024, USDA estimated the national soybean yield average at 51.7 bushels per acre (bpa), yet there are growers who routinely double this yield. And on one farm in southeast Georgia, that average has been quadrupled.

During the past two years, Alex Harrell of Leesburg, Georgia, has gained recognition for unleashing the yield potential of his beans. In 2023, he became the first soybean grower to exceed 200 bpa with a plot that yielded 206.7997 bpa; and this year, he broke his own record with a yield of 218.2856 bpa.

During a recent webinar, Harrell joined Pioneer's Mary Gumz, agronomy innovation leader for the Eastern commercial unit, and discussed steps that farmers can take to realize higher soybean yield potential in their fields.

During the hourlong conversation, Harrell shared the following tips for getting more bushels out of every acre:

-- FIND FERTILITY BALANCE

"Imbalanced soils will grow imbalanced plants," Harrell said, noting that the process on his farm begins with one-acre grid sampling to determine base saturations in the soil. "We want our calcium in the 60% to 70% range, our magnesium at 12% to 16%, our potassium as high as we can get (5% to 8%), sodium less than 1%, and hydrogen will take up the rest."

Once base saturations are in good balance, he begins addressing other fertility needs for the soybean plant, both macronutrients and micronutrients. He said while nutrient levels are important, it's just as important to look at nutrient ratios.

"Phosphorus to zinc is a big one for us. Iron-to-manganese ratio is a big one in soybeans," Harrell said. "I can guarantee you the (soils) that have balanced ratios will always, always, always out-yield the ones with imbalanced ratios, even if those have higher levels."

-- SELECTING SEED THAT SUCCEEDS

While Harrell pays attention to the results of variety trials conducted by universities and other entities, he doesn't base his seed choices solely on such data because "their management style is different than our management style.

"They give us a baseline to start with, but we do on-farm trials ourselves," he said. "We do small-block and large-block trials and then kind of narrow down what fits us better. We want the highest yielding, but that's not the only driving factor. We've got a big checklist that we go down and base (variety selection) off an overall score."

In southeast Georgia, Harrell has been planting full-season indeterminate soybean varieties ranging from early to late-maturity group 4 (MG 4) in recent years. In 2023, when he initially broke the soybean yield record, he planted Asgrow AG48X9, a MG 4.8 indeterminate soybean. This year, he broke his own record with Pioneer P49Z02E, a MG 4.9 indeterminate.

-- PLANT EARLY

To get his soybeans into grain fill during the longest days of the year, Harrell plants as early as he can. He plants all his soybeans before his corn. In 2024, his record-setting field was planted on March 21. That planting date allowed his soybeans to reach the mid-grain fill stage, which is when final seed size is determined, by the official start of summer.

"June 21 is our sweet date. That's the longest day of the year," he said. "Wherever we're at on that day is kind of going to tell us what kind of yield potential we have.

"Even if you're in Minnesota, planting earlier will give you those longer days during the reproduction stages of the plant," he continued. "Any time we can lengthen those reproduction days, you're going to end up with larger bean size and better grain fill."

-- PLANT PRECISELY

While getting the seed in the ground early is important, it's not a job that should be done haphazardly. Harrell admitted to taking an "insane" amount of time on planter setup and ensuring that seed is spaced as uniformly as possible.

"Emergence is king in corn; everybody knows that," he said. "In soybeans, my opinion is singulation will be the biggest (driver in yield swings)."

He noted that he's seen as much as a 60% difference in pod counts on plants with poor singulation and excellent singulation in a 20-foot stretch of row. His planter is equipped with a monitor, and if he sees singulation fall to even 98.5%, he stops to figure out why.

"Skips don't really bother me. They'll kind of fill in, but the double drops with two seeds close to each other, that's where we're going to run into problems," Harrell said. "The more we can get in that excellent singulation box versus poor singulation box, the higher the yields. And that's just free bushels. You don't have to spray anything to get that."

-- LIMIT LIMITING FACTORS

Harrell plants soybean seed that's treated with fungicide, insecticide and biologicals. He also applies an in-furrow blend containing as many as nine products. No matter the products in the mix, he said the key to higher yields is determining limiting factors and fixing them. To do so, he conducts tissue sampling.

"We don't gain yield by adding stuff. We gain yield by taking away the limiting factor," he said. "We sample heavily throughout the year. I tissue sample every Monday, and we build a trend line off those tissue samples. Whatever the limiting factor is, that's the one we're going to fix, whether it's something as small as molybdenum or as big as nitrogen and phosphorus or potassium. If we're deficient in boron, adding more phosphorus and potassium is going to do absolutely nothing for us but waste money."

Harrell said he is a proponent of fungicides. He employs a fungicide seed treatment and applies other products in-furrow and through both the vegetative and reproductive stages -- as late as the R5 (beginning seed) stage.

"I never want to see disease, so we're spraying fungicide preventative, and we're also spraying it for plant health," he said, also noting that he wants a pH of between 5 and 6 for his final solution. "These late applications are really helping us pump those plants up and carry out, and that's just helping to drive yield. I would rather cut fertility and add a fungicide spray if I was trying to save money."

-- HARVEST ASAP

Harrell said his full-season soybeans will reach maturity in mid-August, at which time he will apply a desiccant to kill the plants. He makes his application when the beans at the second-highest node have completely separated from the pod membrane. This strategy allows him to get into the field two weeks earlier and helps maintain test weight, avoid shattering and ultimately preserve yield.

"When a crop matures, it doesn't get any better. It's only going downhill from there," he said. "You're losing yield every second of the day at that point, so I like to get them out as fast as we can because you're not gaining anything else by leaving them out there."

Go here to watch Pioneer's full-length webinar with Harrell: https://youtu.be/….

Read more from DTN about Harrell's 2024 world-record-setting soybeans here: https://www.dtnpf.com/….

Jason Jenkins can be reached at jason.jenkins@dtn.com

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