Sulfur is an essential nutrient for corn and historically, sulfur application has not been recommended in Illinois because of soil supply, manure application, and atmospheric deposition was sufficient to supply sulfur needs. Studies conducted in the late 1970's suggested very little chance for sulfur fertilizer response.

However, soil sulfur levels or supply may have diminished since that study was conducted, notes Fabian Fernandez, University of Illinois Extension soil fertility specialist. The Clean Air Act of 1970, increasing crop yields, and changes in fertilizers and fungicides have impacted the "supply" of sulfur.

In order to quantify the potential for a yield response to sulfur application, sulfur trials across Illinois are being established again in 2010. Volunteers are being identified that would like to participate in an on-farm study to measure corn response to sulfur application.

While the emphasis will be conducting the studies on light colored, coarse textured soils with less than two percent organic matter, "heavier", darker colored soils will be considered. However, fields that have received manure or sulfur application within the last five years will not be considered.

According to Fernandez, farmers conducting the trials will need to follow a simple design applying 0 and 30 pounds sulfur per acre as a broadcast application in a uniform portion of the field. A minimum of three replications or as many as eight replications are needed for each field. These strips can be anywhere from 8 to 16 rows wide by 300 to 1,000 feet long.

Sulfur sources will be limited to either ammonium sulfate, MicroEssentials™ sulfur, or elemental sulfur. Spring broadcast application is preferred. The host farmer will need to provide the yield for each strip based on a weigh wagon or combine yield monitor. Fernandez and his research team will visit the site two to three times during the growing season to take soil and plant samples.

Those interested in participating, or having questions, should contact Fabian Fernandez, Department of Crop Sciences, phone 217-333-4426, email fernande@illinois.edu