No-Till, No Yield? Are We Putting Corn Above Soybean Yields?
- Buz Kloot, Ph.D.
- Jul 21
- 3 min read
Updated: Aug 20
As a response to several requests for more peer-reviewed material on the economics of no-till (NT) vs. conventional tillage (CT), I went digging into the usual suspects — input costs, yield comparisons, and long-term trials. That’s when I stumbled on research from South Dakota State University’s Beresford Research Farm that made me realize: I had a bias.
In an earlier blog, we cited a meta-analysis showing no-till yields averaging 5.7% lower overall compared to conventional tillage [1]. Like many, I assumed this applied across the board, including soybeans. To my surprise (and delight), I was wrong.
The Surprising Soybean Advantage
At SDSU’s Beresford farm, Pete Sexton and colleagues tracked no-till vs. conventional tillage over 27 years. In the corn–soybean rotation, conventional tillage corn out-yielded no-till corn by 6.1 bu/ac — right in line with national averages.
But here’s where things got interesting:
Soybeans yielded 1.8 bu/ac higher under no-till.
Even more striking, when the team expanded into three- and four-year rotations — adding small grains like wheat or oats — no-till corn not only caught up but edged ahead by 1.3 to 1.8 bu/ac, and soybeans gained 1.4 to 2.5 bu/ac [2].
Natalie Sturm’s 2022 master’s thesis at Dakota Lakes Research Farm reinforces the pattern: when rotations included small grains and legumes, no-till yields improved alongside soil health [3].
It’s Not Just No-Till — It’s How You No-Till
So why does the “no-till, no yield” slogan persist?
Corn-Centered Thinking
In the Midwest, corn is king. It’s the economic driver, the benchmark. But soybeans — less sensitive to cool soils and quicker to benefit from improved water retention and structure — often outperform under no-till. They just get left out of the story.
Short-Term Focus
No-till is not a plug-and-play swap. It’s a system change. Early years can show uneven corn performance, but over time, synergistic practices like longer rotations and cover crops help unlock the full potential.
Framing in Research & Media
Much of agronomic research — and almost all the headlines — focus on single-year, single-crop results, not long-term, system-wide gains.
As Natalie Sturm put it in her thesis: “It’s not just no-till — it’s how you no-till.”
Do Real Farmers see this, or is this just Theoretical?
Jesse Hall, a no-till farmer in Kingsbury County, offers a clear example. By adding small grains to his rotation, Jesse saw soybean yields improve by 3 to 5 bu/ac across his farm average.
His success didn’t come from adding more inputs — it came from diversifying the system.
The Big Question: What Will It Cost?
Naturally, the next question farmers ask is:
“If longer rotations improve no-till performance, what will it cost me?”
It’s a fair question — and one we’ll dig into next.
Early data from long-term trials at Brookings, South Dakota, suggest that diverse no-till rotations — even when they shift acres away from corn — can actually increase net income, thanks to lower input costs, reduced chemical use, and improved weed control.
In short, stepping beyond the corn–soybean cycle may not be a cost — it may be one of the smartest profitability strategies on the farm.
References
1. Pittelkow, C. M., Liang, X., Linquist, B. A., et al. (2015). Productivity limits and potentials of the principles of conservation agriculture. Nature, 517, 365–368. https://doi.org/10.1038/nature13809
2. Sexton, P., Rops, B., Stevens, R., Williamson, G., & Sweeter, C. (2018). Long-Term Rotation and Tillage Study: Observations on Corn and Soybean Yields – 2018 Season. In Southeast South Dakota Experiment Farm Annual Progress Report: 2018 (pp. 21–24). https://openprairie.sdstate.edu/agexperimentsta_rsp/279
3. Sturm, N. (2022). It’s Not Just No-Till: Crop Rotations are Key to Improving Soil Quality and Grain Yields at Dakota Lakes Research Farm (Master’s thesis). South Dakota State University. https://openprairie.sdstate.edu/etd2/366
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