Sulfur fertilizer is a mineral that is used to increase the amount of plant life. It is made of sulfur and water. Sulfur can be found in many rocks, coal, and soil. When sulfur is exposed to water, it forms a chemical reaction that creates sulfuric acid. When this chemical reaction occurs, it causes an oxidizing agent. This agent releases oxygen into the air and it makes the water less acidic. Sulfur is also a major component of smog.