Sulfur fertilizer is an increasingly important part of crop nutrition for corn and soybean growers. Among its other benefits, sulfur helps plants fully utilize nitrogen and produces amino acids that make up proteins in soybeans.¹
In some corn fields with sulfur deficiency, the use of sulfur fertilizer has contributed to an average yield bump of 11 bushels per acre.² Experts recommend prioritizing sulfur fertilizer for corn specifically because it delivers a greater production benefit in corn than in soybeans. However, soybeans might enjoy a small benefit by scavenging sulfur and other unused nutrients as part of a corn-soy rotation.³
Sulfur needs vary widely by field and soil type, and sulfur and nitrogen deficiency can appear similar on the surface. Here’s how to determine which fields might benefit from sulfur, how to distinguish between sulfur and nitrogen deficiency, and what you need to know if a sulfur rescue application is needed.
Conditions that increase likelihood of sulfur deficiency
Corn requires between 0.05 pounds and 0.10 pounds of sulfur from the soil for each bushel of grain produced.⁴ Corn sulfur deficiency most often occurs in fields with low organic matter. It also occurs in fields with coarse and sandy textures.
Watch for possible sulfur deficiency if you practice no-till or grow continuous corn, or if your soil is cold and excessively wet or dry.
Differentiate between sulfur and nitrogen deficiency
To determine whether your crop might be experiencing sulfur deficiency or nitrogen deficiency, scout for these telltale signs.
In corn:
- Sulfur deficiency appears early, first on younger and upper leaves, as sulfur has low mobility within the plant. By contrast, nitrogen deficiency appears on older, lower leaves.
- Sulfur deficiency results in pale yellow striping of leaves, whereas nitrogen deficiency leaves a yellow “reverse V” mark.
In soybeans:
- Sulfur deficiency presents as small and pale-green younger leaves with hard and thin stems, whereas nitrogen deficiency results in yellowing leaves.
Determine when a sulfur fertilizer rescue application is warranted
Before applying sulfur, determine your crop’s needs by conducting visual scouting and tissue testing before V6 corn growth stage. Proper diagnosis is the first step to determining if a rescue application is warranted.
Although soil testing is a poor tool for determining sulfur deficiency, tissue sampling your crop is a reliable way to evaluate sulfur availability. You can also conduct strip trials in corn over several seasons—some rows with sulfur fertilizer applied, others with none—to evaluate whether you see a benefit with your farm’s unique blend of soil, management practices and environmental conditions.
Pay attention to pH. If your soils have low pH, it can make sulfur and other nutrients less available to your crop, stunting root development and exacerbating other deficiency symptoms.
How to time an application for sulfur deficiency in corn
If you and your trusted adviser determine sulfur is needed, you can apply sulfur fertilizer anytime from spring through early crop stages.
There are various ways to apply sulfur fertilizer. You can band it or broadcast it. You can combine it with other fertilizers such as nitrogen, phosphate and potash. You can also mix it with a liquid fertilizer, though you should check their compatibility first.
Elemental sulfur fertilizer should be used well before your corn crop needs it. Alternatively, you can use elemental sulfur in combination with sulfate that contains fertilizer.
If you use ammonium thiosulfate as your source of sulfur, don’t place it in the seed furrow because it can damage corn seedlings.
Sulfur fertilizer application recommendations
In cases of corn sulfur deficiency, yield response is typically best with 15 pounds of sulfur per acre on fine-textured soils and 25 pounds per acre on coarse or sandy soils.⁵ The same rates can be applied to soybeans.
If you are using a corn-soybean rotation, apply these rates ahead of corn years because your corn yields will respond more than your soybean yields. Plus, you won’t need to apply more sulfur the next soybean year. If you grow corn on corn, apply sulfur every other year.
Experts are available to help you diagnose and treat sulfur deficiency in corn plants and soybean plants. Reach out to your ag retailer, a nearby extension office agent or a trusted company professional like your regional BASF representative.
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Endnotes
- Albert, Derek. “Researchers Explore Sulfur, Micronutrient Fertilizer Applications.” Louisiana State University AgCenter, 17 Aug. 2022,https://www.lsuagcenter.com/articles/page1660765905492. Accessed 2 Mar. 2026.
- Anderson, Meaghan, and Richard T. Roth. “Who Needs Sulfur? You Might Need Sulfur.” Integrated Crop Management, Iowa State University Extension and Outreach, 9 Oct. 2024,https://crops.extension.iastate.edu/post/who-needs-sulfur-you-might-need-sulfur. Accessed 2 Mar. 2026.
- “Is It Worth Applying Sulfur to Your Soybean Crop?” Minnesota Crop News, University of Minnesota Extension, 8 Apr. 2024,https://blog-crop-news.extension.umn.edu/2024/04/is-it-worth-applying-sulfur-to-your.html. Accessed 2 Mar. 2026.
- Woodmansee, John E. “Should I Plan to Add Sulfur to Crops?” Purdue University Extension, 21 Jan. 2022,https://extension.purdue.edu/news/county/whitley/2022/01/should-i-plan-to-add-sulfur-to-crops.html. Accessed 2 Mar. 2026.
- Sawyer, John. “Crop Sulfur Fertilization This Spring.” Integrated Crop Management, Iowa State University Extension and Outreach, 25 Mar. 2020,https://crops.extension.iastate.edu/cropnews/2020/03/crop-sulfur-fertilization-spring. Accessed 2 Mar. 2026.
