Historically, sulfur (S) application has not been recommended on Iowa soils for corn and soybean production. Soil supply, or a combination from sources such as soil organic matter, profile sulfate, manure, and precipitation have met crop S needs. However, over the past several years, S deficiencies in alfalfa and corn have been documented. Large crop yield responses have been measured in some fields containing soils with low organic matter, side-slope landscape position, or coarse soil texture, especially in northeastern Iowa. The objective of this study was to determine S response of corn and soybean in north-central Iowa.
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