ANALYSIS OF SYNTHETIC GYPSUM

ANALYSIS OF SYNTHETIC GYPSUM

S.Renugadevi, M.Sc., M.Phil., B.Ed.,

Preface

Gypsum is one of the earliest forms of fertilizer used in the United States. It has been applied to agricultural soils for more than 250 years. Gypsum is a moderately soluble source of the essential plant nutrients, calcium and sulfur, and can improve overall plant growth. Gypsum amendments can also improve the physical and chemical properties of soils, thus reducing erosion losses of soils and nutrient concentrations (especially phosphorus) in surface water runoff. Gypsum is the most commonly used amendment for sodic soil reclamation and can be included as a component in synthetic soils used in nursery, greenhouse, and landscape applications. These multiple uses of gypsum represent potential benefits to agricultural and horticultural users.

Currently, a large amount of flue gas desulfurization (FGD) gypsum is produced by removal of sulfur dioxide (SO₂) from flue gas streams when energy sources, generally coal, containing high concentrations of sulfur (S) are burned. Initially, most of the FGD gypsum produced in the United States was used in the wallboard industry and only a small amount was used in agriculture. However, FGD gypsum is suitable for agricultural uses and, similar to mined gypsum, can enhance crop production. As with other fertilizers and agricultural amendments, FGD gypsum must be used appropriately to avoid potential negative impacts on both agricultural production and the environment. In many respects, there are similarities between the agricultural use of FGD gypsum and nitrogen fertilizers in that both can provide crop production benefits but, if improperly used, can also lead to negative environmental impacts.