Sulfur is an essential plant nutrient. In previous years Sulfur was delivered free to the farm by rain. Volcanoes and fossil fuel burning power plants release millions of tons of S annually. This Sulfur was then brought to earth with rain and snow. While the government cannot regulate volcanoes the EPA has restricted Sulfur emissions from fossil fuels. S deficiencies in rice are increasing each year.

Most of the Sulfur in soil is contained in soil organic matter. This sulfur is made available to plants by bacterial action. Soil bacteria increase in numbers and activity as the temperature goes up. The University of Missouri recommends applying Sulfur only on soil with a CEC of less than 7.5. This would preclude Sulfur fertilization for most rice production fields. This recommendation was developed during the early 1970’s and reflects Sulfur carried to the soil by rainfall.