Is Strip-Till the Solution to Soil Stratification?

Marion Calmer noticed symptoms of nutrient deficiencies in his corn a few years ago. He began to wonder if soil stratification — the accumulation of phosphorous (P) and potassium (K) in the surface — was a problem on his no-till farm in Alpha, Ill.

“My soil tests looked fine, but something was wrong,” Calmer says. “A dollar worth of P and K was only producing 40 cents worth of grain.” 

Extensive soil testing confirmed what the veteran no-tiller suspected.  

“At my particular farm, 50% of my P and K is in the top 2 inches of the soil,” Calmer revealed during his presentation at the 2023 National No-Tillage Conference in St. Louis, Mo. “Half of the nutrients are above where I plant the seed. I’ve got a stratification problem.” 

He’s not alone. Calmer’s research also found that stratification only gets worse over time, with the top few inches of the soil getting higher and higher in fertility and the root zone getting lower and lower. He tried moldboard plowing 1.6 acres at his home farm to see if it would lead to destratification in his soil, and the moldboard plowed field outyielded his no-till soybeans by 9 bushels per acre.

“That’s pretty tough for me to swallow,” Calmer says. “$135 per acre on 1,000 acres is $135,000 I left on the table last year because my P and K are stratified on the surface.” 

This begs the question — could strip-till be the solution for Calmer and the many others struggling with this problem? 

“It sure seems like it,” a no-tiller in the crowd at the National No-Tillage Conference said to a member of our crew after Calmer’s presentation.

The No-Till Innovator award winner isn’t advocating for anyone to go out and conventionally till their fields, but Calmer knows he needs to change something to recover that $135,000 left on the table last year.   

“I know stratification is real,” Calmer says. “This is not a no-till problem. The problem is Marion Calmer’s management was wrong when he no-tilled. I’ve got to change. I’ve got to hit the restart button somewhere. Either mechanically put P and K in the root zone, whether it’s strip-till or with the planter.”

Toward the end of his presentation, Calmer shared the stories of 4 high-yielding farmers who have seemingly unlocked the secret to soil destratification: Herman Warsaw (370 bushels per acre of corn), Francis Childs (440 bushels), Randy Dowdy (521 bushels) and David Hula (616 bushels). 

What do they have in common? 

“They all believe in putting their P and K in the soil profile, not above the roots,” Calmer says. “They want it in the root zone, and I would agree with them.”

It’s like Vegas — what happens in Vegas stays in Vegas and where you spread your P and K is where it’s going to stay, Calmer analogized during his presentation. But what happens at the National No-Tillage Conference doesn’t stay at the National No-Tillage Conference. Calmer’s observations have no-tillers and strip-tillers alike talking about the benefits of strip-till’s nutrient placement. What do you think — is strip-till the solution to soil stratification? Calmer will present his latest research at the National Strip-Tillage Conference, August 3-4 in Bloomington, Ill.