FREMONT, Ohio — Gypsum, or calcium sulfate, was one of the earliest forms of fertilizer, said Ryan McBride, Ohio sales manager for GYPSOIL, a synthetic agricultural gypsum.

“Gypsum has been applied to the soil for more than 250 years,” he explained. “It is a nutrient source and also a soil conditioner with soil amendment properties. It improves soil tilth. Gypsum allows for the quick release of calcium and sulfate ions into the soil and reduces soil crusting.”

Nick Rulon is part of Rulon Enterprises, a large family farm based in Arcadia, Ind. He grows corn and soybeans; he started testing gypsum about 10 years ago and began using it on all the fields three years ago.

“We’ve had certain situations as far back as 10 years ago where we needed a lot of sulfur in a certain area; it’s really good for sulfur,” he said. “We used it regularly because of the overall benefits that we’ve been getting from it.”

Rulon no-tills and using gypsum increased water permeability. This allowed him to use no-till continuously. Testing on side-by-side fields, Rulon found a five- to 10-bushel per-acre increase in soybean yields in fields treated with gypsum and between a 15- to 20-bushel increase on cornfields.

“We are in an every-other-year rotation (applying gypsum),” he said. “We started out with a base one ton to the acre on everything. We skipped a year and now we’re variable-rating. That’s anywhere between 8/10 of a ton (to the acre) for the whole farm and certain areas where there are water holes, where we put on around two tons. We have mostly silty loam soils.”

Rulon, who spreads about 3,000-4,000 tons of gypsum a year on his farm and custom spreads on other farms, used a 5034 model New Leader Compost Spreader, a chain-driven machine, to spread it.

“It just grabs it and throws it right off the back, and it spreads great,” he said. “The synthetic gypsum we use comes out of Indianapolis.”

Synthetic gypsum is more readily available since the Clean Air Act Amendments of 1990. That gave rise to new scrubbing systems used by many coal-fired utilities to remove sulfur dioxide from their emissions, said Ron Chamberlain, chief agronomist of GYPSOIL. Synthetic gypsum is a byproduct of that process and is sometimes called flue gas desulfurization (FGD) gypsum.

“Farmers who learn about gypsum want to use it because it changes soil structure and allows the soil to become very friable, very aggregated,” said Chamberlain. “When it rains, these fields drain better and when the rain moves through the soil and the oxygen follows, then the soil biology becomes very active. So the soils begin to aggregate and farmers will get more working time between rains.”

When the soil becomes more mellow, as the biology comes into balance the cost of fertilizer may decrease and it will certainly become more effective, Chamberlain said.

Another “win” in this situation is that gypsum, through a couple of methods, actually reduces the amount of nutrient loading in the watershed from treated fields.

“That is a very important thing today, with phosphorous and nitrates moving into our watersheds,” Chamberlain said. “Gypsum does have a direct chemical interaction with those nutrients, but also just in opening up the soil, balancing the soil biology and the chemistry, rather than to erode off the field, gypsum helps the material to be absorbed down into the soil where the soil biology then can tie it up.

“The key is that gypsum aids in efficiency in farming practices, and aids the soil’s efficiency in gathering the rainfall, the sunlight, the nutrients, and makes a more salable crop. The efficiency of the farmer’s inputs is enhanced and the quality and quantity of outputs is increased, as well.”

The cost of using gypsum varies, starting with about $20 an acre and up depending on shipping distance, Chamberlain said. For more information, visit www.gypsoil.com