Gypsum: A Sulfur Source that Does More
Oct 13, 2026
Sulfur is an essential nutrient for plant growth, so it can sometimes be important to add it to your soil. We like to use gypsum as a sulfur source for many reasons, and now is a great time to apply it.
“We use SO4 Pelletized Gypsum,” said Rod Gustafson, Federated agronomist in Albertville. “It offers 17% Sulfur and 21% calcium, with a slow release of sulfur over time that reduces leaching.”
Gypsum is pH neutral, so it doesn't acidify the soil like some products, meaning you don’t have to plan to even out its impact on acidity. Best of all, using gypsum year after year can pay off.
“The benefits of gypsum are additive,” added Federated agronomy sales manager Kevin Carlson, “If you use it at 150 to hundred pounds per year as a sulfur source, eventually you get to soil amendment rates, which is important for reduced tillage, no-till, and strip-tillage. It also helps alleviate crusting of the soil in the spring.”
Over time, gypsum will help balance the magnesium levels in soils that test high for magnesium. It can also gradually improve water infiltration rates and help loosen compacted soils. SO4 is a medium-release product, and at 500 to 2000 pounds per acre, it helps a lot with soil aggregation and friability.
“We like SO4 because it’s very application flexible,” Carlson said. “It can be mixed with fertilizer and potash, making fall a great time to apply.”
“It’s also approved for use in certified organic production,” said Gustafson, “which broadens its appeal. It’s natural gypsum, mined and manufactured in Fort Dodge, Iowa.”
To get gypsum applied to your fields this fall, give your Federated Agronomist a call!