Indiana Prairie Farmer publishes a column written by Tom Bechman with the help of CCAs for CCAs and their clients. With permission from Prairie Farmer we are posting these Corn and Soybean Corner articles on the CCA website. Many thanks to the authors and the support of Indiana Prairie Farmer.
Corn Corner Articles
Consider pros, cons of fall fertilizer application
Answers are from the Indiana certified crop adviser panel: Danny Greene, Greene Crop Consulting, Franklin; Bryan Overstreet, soil conservation coordinator, Rensselaer; Dan Quinn, Purdue Extension corn specialist; and Dan Ritter, Dairyland Seed agronomist, Plymouth.
Should I apply phosphorus and potassium fertilizer after soybeans for next year’s corn crop now or wait until spring? Price is part of it, but I like to make sure it gets on before planting the crop. Some fields are rolling. Should I wait until spring on those fields?
Greene: On sloping ground, rolling terrain or flood-prone areas, spring applications of P and K are generally safer. Nutrients applied closer to crop uptake are less likely to move off the field, improving efficiency and protecting water quality.
On soils less prone to loss, fall application spreads out the workload, avoids risk of spring delays and ensures fertilizer is in place well before planting. Every day of delayed corn planting can cost yield, so spring application comes with its own risks if weather or field conditions push things back.
Balance three factors:
- Risk of nutrient loss. This can be due to slopes, erosion potential or flooding.
- Operational capacity. How much spring workload can your equipment and labor realistically handle?
- Economics. Consider input prices, fuel and labor costs, as well as the potential yield impact of delayed planting.
Use soil testing and field-specific risk factors to guide your plan, and use both strategies as needed. Applying fall fertilizer on lower-risk fields while holding higher-risk acres for spring application can be a sound strategy.
Ritter: Price will be a major factor in many agronomic decisions for 2026. I prefer fall application simply from a soil condition standpoint. Waiting until spring increases issues of soil compaction. Applied in fall, fertilizer can work into the soil solution and be readily available. Even in the spring, rolling fields could have the same issue until fertilizer is in soil. Applying to frozen soil is not recommended on rolling ground.
Overstreet: As an old fertilizer retailer, I say apply in the fall while you have time. But as a conservation agronomist, I say wait until spring. You won’t worry about losing nutrients to runoff or leaching. Waiting keeps surface waters cleaner, and fertilizer is more beneficial when it stays put.
Work with your dealer to set price now so you can fix that cost. There have been some studies on soybeans that show that if you apply next spring, you need at least one good rain on a potash application before planting due to the chlorine concentration. I have not heard of this issue affecting corn.
Quinn: Both fall and spring applications of P and K can be effective. In most cases, yield results are similar regardless of timing due to limited mobility of each of these nutrients in the soil. The key is to be sure applications are based on routine soil testing so you’re applying correct rates for your fields.
It’s also important to be consistent in time of year in which you collect soil samples. Results can vary depending on season and soil conditions. For rolling ground or areas prone to surface erosion, delaying application until spring may be helpful to limit nutrient losses. Overall, applying in the fall is fine, but remembering to base your decision on soil test results, field conditions and your operational needs is important.
