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How Iowa farmers hit triple-digit soybean yield

Duane Reeder’s 102-bushel-per-acre soybean yield in a 48-acre field last year is rooted in his University of Northern Iowa college days.

“Everyone in our apartment complex was invited to an acquaintance party,” says the Lawton, Iowa, farmer.  Long story short, that’s when he met his wife, Rhonda. This also springboarded his 43-year farming career when he met his father-in-law, the now-retired 92-year-old Walter Reinholdt.

“He was a northwestern Iowa farmer always looking at new practices and how to do things better,” says Reeder. 

In 1965, for example, Reinholdt read a farm magazine article about a farmer who used a light disk as a minimum-tillage implement. This intrigued him, for this was a time when many farmers heavily tilled their fields. Reinholdt found a similar tandem disk that lightly disked fields while leaving surface residue intact. 

Reinholdt used an Allis Chalmers planter that permitted him to plant through the resulting thick residue. He tested it on 40 acres before adopting the practice across his entire farm the next year.

Flash forward to the 1980s, when Reinholdt’s philosophy on adopting new technologies like conservation tillage had helped Reeder through the 1980s farm crisis. Reinholdt also knew some farmers who were using an AerWay vertical-tillage tool. 

“They let us try it, and that’s all I’ve done for tillage since, after I apply fall fertilizer,” says Reeder. “It punches holes in the ground while keeping the residue on the surface.” This helps water infiltrate the soil while still maintaining surface residue and soil structure, he adds. 

Aiming at 100 

Soil intact, Reeder teamed with Chad Lewis, an agronomist with First Cooperative Association in Kingsley, Iowa, to aim for higher corn and soybean yields. Although there was no state or national soybean yield contest where Reeder farms, they challenged the 100 bushel per acre-plus yield contest winners through yield-enhancing practices. 

Lewis’ interest in shooting for triple-digit soybean yields was perked by an Iowa State University meeting where Randy Dowdy, the Valdosta, Georgia, corn and soybean yield champion, spoke. 

“He said, ‘You guys in Iowa can do 200-bushel corn without even trying,’ ” Lewis remembers. “I took offense at that. We’re pushing yields higher than that. We can do this.”

So, Reeder and Lewis set about emphasizing certain practices in the 48-acre field by mimicking a yield contest that included the following. 

  • Variety selection

Midwestern farmers like Reeder can’t plant the longer-maturing soybean varieties with high-yield potential like southern farmers can. Still, it was a 2.8 relative maturity variety that clocked in at 102 bushels per acre in the field, mimicking the yield contest.

“I bought (soybean varieties) from five or six different seed companies last year, and they all turned out to be good yielders across the farm,” says Reeder.  

Reeder selects soybean varieties with high-yield potential coupled with a sound defensive package that fends off diseases like white mold and brown stem rot. “I have been planting soybeans that resist soybean cyst nematode-for the last 20 years,” he adds. 

Variety performance is also aided by planter technology, such as on-the-go seeding adjustments and individual row shutoff, Reeder adds

He also teams these varieties with seed treatments to fend off early-season disease. “With a good defensive package, seed treatments and the right maturity do fine,” says Reeder. 

“If you feed them,” adds Lewis.

  • Fertility

Reeder agrees, adding ample soil fertility is another attribute instilled to him by his father-in-law.

“There’s no free lunch –whether in farming or in business,” he says. That’s why his soybeans receive their own fertility regimen each year, rather than relying upon carryover fertilizer from the previous corn crop. 

“We’ve been pulling 2½-acre grid samples for the last five years across the farm,” says Reeder. “It costs about $1,000 per quarter, but it has been a big step forward.” 

It keyed the importance of applying 0-100-100-20-10 on corn ground going into soybeans the next year after fall tillage. On the field mimicking a yield contest, this mix of phosphorus (P), potassium (K), sulfur (S), and zinc (Zn) was followed by subsequent fertility applications keyed by tissue tests. 

“I can’t emphasize how important this is,” Reeder says. “Tissue tests show which nutrients the crop takes up and what is missing.” 

A tissue test keyed an over-the-top application of dry 30-40-60 on July 17, and weekly testing and subsequent fertilizer applications commenced from there. Tissue tests assessed plant nitrogen, P, K, S, Zn, manganese, magnesium, calcium, and iron levels. After the July 17 dry application, they followed up with foliar nutrient mixes. 

“We would test every week on Monday, get the results back by Wednesday, and be applying Thursday or Friday,” says Lewis. “We sampled every week, because things can change fast, and each tissue sample cost only $12,” says Lewis. 

One advantage Reeder has is his own sprayer that enables him to make foliar applications. That will help him make as-needed fertilizer applications as he expands tissue testing over the rest of his farm a couple times during the growing season this year.

  • Pest Control

Having his own sprayer also aided Reeder with herbicide applications to manage weeds. One weed-control tool didn’t involve chemicals, though. He drilled soybeans in 7½-inch rows with a John Deere 750 no-till drill at a seeding rate of 165,000 plants per acre on the field mimicking the contest. This made for an early-closing canopy that snuffed out any late-emerging weeds.

He complemented this with a burndown mix of 2,4-D (Group 4) and glyphosate (Group 9) followed by a sulfentrazone (Group 14) preemergence application that’s included in Authority products. He followed up with a postemergence herbicide application that included Flexstar GT (Group 14 and Group 9).

On the contest field, he also added two in-season applications of fungicide and insecticide. Reeder and Lewis say this paid off, and Reeder say he plans to apply a similar application across his entire soybean acreage in 2020. So far, soybean gall midge has not been a threat.

Coming Up in 2020

The only thing we can’t control is Mother Nature,” says Lewis. That was the case in 2019 with planting date. Reeder couldn’t plant soybeans in the field that yielded 102 bushels per acre until May 13. Still, favorable summer weather prevailed after a rough start.

“The only things we lacked were some heat units,” says Reeder. “Other than that, it was an ideal year, with the best yields we’ve ever had for both corn and soybeans.”

In 2020, Reeder plans to tweak row spacing, planting soybeans with a planter in 15-inch rows and dialing back population rates a bit. Otherwise, he and Lewis plan to keep pushing practices on contest fields and transferring knowledge gleaned across his entire farm. 

“It’s important to get a good agronomist who can help you do this,” says Reeder. They plan to enter an official soybean yield contest in 2020 on three of Reeder’s soybean fields. 

“I’ve never had so much fun farming. Had I known all this when I started in 1977, I would have been dangerous,” jests Reeder. 

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