Phosphogypsum (CaS04), a by -product of phosphoric acid production from rock phosphate is a potential source of calcium and sulfur for plants, as well as an ameliorant for alkaline and sodic soils. Phosphogypsum production worldwide exceeds 150 million Mg annually, with only about 4 percent being used in agriculture and industry and the rest being dumped into the ocean or stock piled as a waste. Florida leads in the production of phosphogypsum in the United States with an annual production of 33 million Mg and about 600 million Mg in stacks, and a projection of 1 billion Mg by the year 2000. This paper will discuss the various agronomic uses of phosphogypsum (i.e. source of nutrients for plants, conditioner for sodic soils, hard-setting clay soils and subsoil hardpans, and the acidifying benefits on high pH soils to help alleviate micronutrient deficiencies). This paper will also discuss any potential environmental hazards to be concerned with from using phosphogypsum in agriculture