This presentation will help crop advisers, consultants, and producers in the U.S. Corn Belt and in areas with similar production systems understand the potential for sulfur deficiency and crop yield response in corn, soybean, and alfalfa. The presentation will cover sulfur as an essential element and crop available sulfur sources, including change in sulfur deposition from the atmosphere. Research results will be presented that outline plant and soil sulfur test reliability, and site characteristics that affect potential for deficiency and response to applied sulfur. Examples of sulfur yield responses and determination of sulfur rate requirement will be presented. The information presented will help crop advisers and producers implement proper sulfur management practices for optimal crop production.