Ask an Agronomist
Does Gypsum Provide Any Real Benefit to Soils?
Nov 18, 2011
Question: Does gypsum offer any real benefit to soil?
Answer: Farmers use the naturally occurring mineral to improve soil tilth, water infiltration and nitrogen uptake in their fields. According to the American Coal Ash Association, a utility industry group, farmers used 279,000 tons of gypsum in 2008. That’s more than three times the amount they used in 2002. With gypsum, the soil structure becomes more sponge-like, so even tight clay soils readily absorb water and move it down through the soil profile, rather than allowing it to pond or run off, according to Ron Chamberlain, director of gypsum programs for Beneficial Reuse Management. The company sells a synthetic gypsum product, Gypsoil, for agricultural use. Synthetic gypsum is a byproduct of fossil-fueled power plants that work to remove sulfur dioxide from flue gases in an effort to curb pollution and comply with clean air regulations. In recent years, synthetic gypsum has gained ground with farmers because of its availability and lower price. Purdue University research indicates that gypsum also offsets the impact of aluminum toxicity in low pH soils, helps curb phosphorus runoff and increases iron uptake by reducing the effects of bicarbonates. Some seed companies are conducting field research to determine whether the soil benefits from gypsum also support increased crop yields. To date, the data shows mixed results.