Are you considering growing continuous corn? When weighing the costs and benefits, current high demand for corn may tilt the scale in favor of continuous corn versus crop rotation. However, moving from crop rotation to continuous corn will require a careful strategic change-up in your management of pests, disease, nutrients and more. We’ve compiled a quick overview of how you can make up for potential challenges with continuous corn.
Benefits of continuous corn
Profitability with high demand and commodity prices
Even though U.S. corn values have seen a recent decline with favorable weather and a solid production outlook, increasing ethanol demands continue to support prices¹ and make continuous corn production appealing for many growers. These high demands and commodity prices may be a consideration when choosing whether to plant continuous corn.
Research has shown that applying intensive management techniques in continuous corn increased yield by 50 bushels per acre.²
Challenges of continuous corn
Continuous corn yield penalty
Corn following corn typically produces a lower yield than corn following soybeans or alfalfa without applying specific measures needed for continuous corn. This phenomenon is known as the continuous corn yield penalty (CCYP). The penalty is generally in the range of 20 to 30 bushels lost per acre compared to fields that rotate.
Increased disease and pest risks
With increased residue due to continuous corn, the risk of yield reduction from overwintering pests and diseases increases.
Overwintering pests include but are not limited to wireworms, corn rootworm and white grubs. Seed treatments can be used to safeguard the seed and seedling against early insect threats.
During the season, continuous corn crops may be especially at risk of corn rootworm and European corn borer damage. Planting Bt corn can provide much-needed insect resistance in continuous corn operations.
On the disease front, threats such as gray leaf spot, northern corn leaf blight and anthracnose leaf blight also tend to hit harder in continuous corn cropping systems. Like insect pests, these diseases rely on heavy residue common to corn-on-corn fields.
Planting challenges
Residue in continuous corn fields not only increases pest and disease challenges, it also hampers planting operations. Using the right equipment is key to successfully managing residue in continuous corn, especially in reduced or no-till systems. Proper crop residue management is also key for corn-on-corn operations.
Managing residue may lead to lost working hours as you wait to plant later in the day after residue has dried. If using disk openers, damp or wet residue will not cut easily.
Using row cleaners, making adjustments such as higher downforce on disk openers, or running one or two notches heavier on closing force than you would for a field with lighter residue are all adjustments that can help manage heavy residue. You can also reduce the amount of larger stalk material that the row unit must travel through by shifting the guidance line by half a row width.³
Increased input cost
Continuous corn requires anywhere from 30 to 50 pounds more nitrogen (N) per acre than corn following soybeans. Adding a nitrogen starter fertilizer can help, but not in every situation. The effectiveness of that fertilizer will depend on factors such as how much nitrogen is immobilized by residue decomposition. Additionally, if your soil test results show very high phosphorus (P) and potassium (K) levels, nitrogen starter fertilizer will likely be less effective.⁴
Ways to improve yield for continuous corn
With careful management, you can reap the benefits of continuous corn while managing the challenges. Here are a few key management tips to keep in mind if you’re choosing continuous corn for next year’s crop.
- Choose hybrids developed to withstand the challenges of higher-residue situations
- Look for seed with strong defensive disease packages and excellent seedling vigor
- Manage residue and adjust equipment accordingly to handle heavy residue
- Ensure adequate nitrogen where continuous corn has pulled from the soil
- Manage corn rootworm using a combination of Bt seed as well as Nurizma® soil insecticide applied at planting.
Experts are available to help you make your decisions. Reach out to your seed retailer, a nearby extension office agent, or a seed company professional like your regional BASF representative.
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Endnotes
- Pereira de Carvalho, Victor. “Americas Corn and Soybean Prices Hit Multi-year Lows Amid Favorable Crop Prospects.” Essential Intelligence | S&P Global, 20 Aug. 2024, www.spglobal.com/commodityinsights/en/market-insights/latest-news/agriculture/082024-americas-corn-and-soybean-prices-hit-multi-year-lows-amid-favorable-crop-prospects. Accessed 12 Nov. 2024.
- Bryan, Alison. “Continuous Corn.” Crop Physiology, cropphysiology.cropsci.illinois.edu/continuous-corn/. Accessed 12 Nov. 2024.
- Powell, Levi, and Ryan W. Bergman. “Considerations for No-Till and High-Residue Fields in a Predicted Dry Season.” Integrated Crop Management, 1 Apr. 2021, crops.extension.iastate.edu/blog/levi-powell-ryan-w-bergman/considerations-no-till-and-high-residue-fields-predicted-dry-season. Accessed 12 Nov. 2024.
- Licht, Mark. “Considerations for Continuous Corn.” Integrated Crop Management, 18 Nov. 2019, crops.extension.iastate.edu/cropnews/2019/11/considerations-continuous-corn. Accessed 12 Nov. 2024.
