Corn Performance Improved by Long-term Diversified Crop Rotations and No-tillage in Ohio from 1962 to 2024

Although the interest in conservation agriculture is growing among farmers, practices like no-tillage and more diverse crop rotations—those that go beyond corn, soybean, and wheat—are still not widely adopted in the United States. Today, 82%– 94% of the cropland is managed with crop rotations, but most are just two-year corn-soybean systems, and only about one-third of U.S. acres are under no-tillage practices (Claassen et al., 2018).

Many farmers hesitate to try new practices and crop rotations for a variety of reasons:

• possible yield losses
• higher equipment costs
• limited markets for crops other than corn and soybeans
• challenges of transporting forages
• need for specialized livestock
• effort required to adjust long-standing fertilizer, pest, and weed management practices

Ohio has one of the oldest long-term studies on tillage and rotation in the world —the Triplett-Van Doren no-tillage and crop rotation experiment (soilfertility.osu.edu/research/long-term-tillage-plots) (Figure 1). This research began in Wooster in 1962 and in Hoytville in 1963 (Figure 2) and has been supported by The Ohio State University for over 60 years. Its goal is to understand how different farming practices affect crop yields and soil health. The two founders of this research, Grover Triplett and Dave Van Doren, posed a number of questions:  

1. How much tillage, if any, is needed to grow a crop?
2. How do tillage and rotation interact to influence corn yields?
3. How does soil type (heavy-clay vs. silt-loam soils) influence the responses to these practices?

Using long-term corn yield data (1962–2024) from the Triplett-Van Doren experiment, de Camargo Santos et al. (2025) reported the effects of different crop rotations (continuous corn, a two-year rotation of corn-soybean, and a three-year rotation of corn-forage-forage) and tillage practices (moldboard plow, chisel, and no-tillage) on corn yields at two sites in Ohio with contrasting soil types: silt-loam in Wooster and clay-loam in Hoytville.

Key Findings

Corn yield improved when using crop rotations with forage crops and no-till

More than 60 years of yield data showed higher grain yields when corn is rotated with forage crops (alfalfa, red clover, oats)—especially in no-till systems—in both locations of the study, Wooster and Hoytville (Figure 3). Corn rotated with forage crops under no-till performed best,  yielding an average of 165 bushels per acre and gaining 1.3 bushels per acre each year in Wooster, and yielding an average of 156 bushels per acre with an annual yield increase of 1.6 bushels per acre per year in Hoytville (Table 1). Similar findings have been confirmed by recent studies across the United States and Europe (Bowles et al., 2020; Smith et al., 2023). These studies show that adding perennial and forage crops to grain systems can reduce the need for irrigation and fertilizer, help control weeds, and improve overall crop performance. These benefits are very relevant for today’s agriculture and can help make crops more resilient to challenging and unpredictable weather.

Drawbacks of continuous corn and moldboard plow

Since the early 1960s until 2024, monoculture or continuous corn system had the lowest yields at both Wooster and Hoytville, yielding up to 18% (or ~28 bushels per acre) less than the corn-soybean and corn-forage rotations (Figure 3). Corn-soybean rotations outperformed continuous corn in most crop seasons and tillage systems but still yielded less than all corn-forage rotations over time. In Wooster’s silt-loam soils, the lowest-yielding system was the corn-soybean rotation under moldboard plow, averaging 135 bushels per acre and with an annual yield gain of 1.3 bushels per acre (Table 1). In Hoytville’s heavy clay soils, the lowest-yield system was the continuous-corn under no-tillage, averaging 128 bushels per acre and with annual yield gain of 1.0 bushels per acre (Table 1).

Research shows that crop diversification benefits are stronger when crops are added that build soil health, such as deep-rooted species that improve soil structure, perennial legumes that fix nitrogen, or high-residue plants that build soil organic matter, rather than just increasing the number of crops in the rotation (Costa et al., 2024; Smith et al., 2023). For example, although adding soybeans increases the diversity of corn systems, soybeans have a short growing season and produce low plant residue, leaving soil exposed to erosion from wind and water for long periods. This may explain why long-term and annual yield gains were lower in both continuous corn and corn-soybean rotations compared to corn-forage systems.

Changes in agricultural management need to be well-planned for better results

Early yield penalties from the transition to no-tillage were larger in continuous-corn systems, especially at the Hoytville site. However, adding forage crops to rotations removed these penalties, showing how crop diversity and year-round living roots can help during the early years of no-tillage. In the silt-loam soils of Wooster, no-tillage started benefiting yields within the first three to four years (1963–1969) across all crop rotations. In Hoytville’s clay soils, yield improvements were more dependent on using a diverse and perennial rotation, with continuous corn suffering the longest yield penalties (up to 20 years).

Adjusting management practices to local conditions is vital when shifting from tilled to no-till, as it helps reduce yield declines during the transition period (Triplett & Dick, 2008). The first decades of this research in Ohio had significant challenges because pest-management knowledge in no-till was limited, proper machinery for no-till systems was not yet available, and herbicide technologies were still being developed (Triplett et al., 1963). These challenges had a significant effect on grain yields under no-till during the early years at both locations but have been overcome with equipment advances (such as more efficient, high-residue planters), improved genetics of corn varieties, and a better understanding of how to manage no-till fields, among other factors.

Points to Ponder and Looking Ahead

On average and regardless of soil type, no-till increased corn yields by up to 30 bushels per acre when rotated with forage crops. These results are especially promising for farms that integrate crop-livestock systems. At the same time, farms that do not have livestock can also benefit by having perennial crops with increased diversity that includes shorter rotations or cover crops between annual cash crops. This strategy helps farmers protect their soil, build organic matter, and sustain long-term crop productivity. In silt-loam soils like those in Wooster, no-till practices proved highly beneficial even in corn-soybean rotations. In heavier clay soils, such as those in Hoytville, adding forage crops to the rotation is recommended to fully take advantage of the benefits that no-till can offer for corn production.

Long-term research like the Triplett-Van Doren study provides important lessons about the effects of farming practices over time. Reports from this experiment can help farmers, researchers, educators, and other decision-makers understand the benefits of conservation agriculture and support the adoption of sustainable practices in Ohio and across the region. As farming methods evolve to suit different crops and local conditions, conservation-based systems—especially those that include a wider diversity of crops, use perennial plants, and reduce or avoid tillage—show strong potential to support both high yields and long-term sustainability.

References

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Claassen, R., Bowman, M., McFadden, J., Smith, D., & Wallander, S. (2018). Tillage intensity and conservation cropping in the United States. Economic Research Service, U.S. Department of Agriculture.
ers.usda.gov/publications/pub-details?pubid=90200

Costa, A., Bommarco, R., Smith, M. E., Bowles, T., Gaudin, A. C. M., Watson, C. A., Alarcón, A. B., Blecharczyk, A., Calderon, F. J., Culman, S., Deen, W., Drury, C. F. Garcia, A. G., Garcia-Diaz, A., Plaza, E. H., Jonczyk, K., Jäck, O., Martinez, L. N., Montemurro,…Vico, G. (2024). Crop rotational diversity can mitigate climate-induced grain yield losses. Global Change Biology, 30(5), Article e17298.
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de Camargo Santos, A., Culman, S. W., Deiss, L. (2025). Sixty years of crop diversification with perennials improves yields more than no-tillage in Ohio grain cropping systems. Field Crops Research, 331.
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Smith, M. E., Vico, G., Costa, A., Bowles, T., Gaudin, A. C. M., Hallin, S., Watson, C. A., Alarcón, R., Berti, A., Blecharczyk, A., Calderon, F. J., Culman, S., Deen, W., Drury, C. F., Garcia, A. F., García-Díaz, A., Plaza, E. H., Jonczyk, K., Jäck, O., … Bommarco, R. (2023). Increasing crop rotational diversity can enhance cereal yields. Communications Earth & Environment, 4, 89.
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Triplett, G. B., & Dick, W. A. (2008). No-tillage crop production: A revolution in agriculture! Agronomy Journal, 100(53), S-153-S-165.
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Triplett, G. B., Johnson, W. H., & Van Doren, D. M. (1963). Performance of two experimental planters for no-tillage corn culture. Agronomy Journal, 55(4), 408–409.
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