A study was conducted at ten locations in North Dakota and Minnesota in 2016 and 2017 to evaluate corn response to different sulfur (S) application rates and to determine the relationship between corn yield and plant tests. Five S treatments of 0 (check), 11, 22, 33, and 44 kg S ha-1 were applied as ammonium sulfate granular fertilizer. Significant increase in corn yield occurred at only two sites (out of ten sites) in both years. Application of 33 kg S ha-1 (2016) and 44 kg S ha-1 (2017) increased corn yield by 3.4 Mg ha-1 and 1.3 Mg ha-1, respectively. Poor correlation was noticed between plant tests (tissue S and N/S) and corn yield. These results indicate that response to S varies from soil to soil and weather conditions may play the most important role in determining the response. Additional research should be conducted using different soils over multiple years.