Farmers are asking questions about gypsum. Commercial brands are on the market. In nearly every case, the gypsum being sold today is from utilities where scrubbers are removing compounds from cola so they don't go off into the atmosphere. The gypsum is a by-product that is left over.
At the Purdue Farm Management Tour on three well-managed farms last summer, all three were sold on applying a gypsum product. At least two of them were in no-till and used cover crops, even though their soils were not rolling, for the most part. There is no reason to doubt their results.
Yet from 150 miles farther south, near Fort Branch, Ind., results from two years in demonstration plots at Beck's Hybrids Practical Farm Research Plots, the Southern Indiana version, gypsum they've applied has not produced a benefit. Yields were virtually the same whether gypsum wasn't applied in either year, was applied at one ton per acre in 2009 and one ton per acre in 2010, or was applied at one ton per acre in 2009 and a half ton per acre in 2010, or if just a ton was applied in 2009 and none in 2010.
Scot Ebelhor is in charge of the Beck's southern research farm, an 80-acre plus set of trial plots testing various concepts in corn, wheat and soybeans. The farm is located on level soils in southwest Indiana. Yields both years were right around 220 bushels per acre, plus or minus a couple bushels per ace, no matter what was done.
"Similar to last year's results, this year's study did not show any differences between the entries treated with gypsum and those that were not treated at the southern Indianan PFR farm," Ebelhor writes in a report on the project.
"No visual differences were noted. We will continue the study to see if there are any long-term benefits or effects from utilizing this product."
So three top-notch farmers say it works well for them. A top-notch person who runs demonstration plots says he sees no difference. Both are on different soils, different weather patterns.
The conclusion? If there is one, maybe it's to look for work done as close to you and on as comparable of soils as possible before making up your mind.