Renewable Farming

New research continues to document positive payback for fall-applied gypsum

We’ve applied a ton per acre of calcium sulfate each fall for the past three seasons — and we’ve seen soils mellow out and absorb rain more readily.

This week, we saw one new random-rep corn yield trial indicating that there’s a 10-bu. potential corn yield increase following an application of gypsum from stack scrubbers. The material tested was “Power SC” from BRT Ag & Turf.

That data was reported by Jerry Hatfield, laboratory director and Supervisory Plant Physiologist at the National Laboratory for Agriculture and the Environment. (Formerly National Soil Tilth Lab.)

Dr. Jerry Hatfield

We suspected that kind of response but hadn’t done a strip trial on it. We spread it each fall on every acre, buying the product from BRT Ag & Turf at Ladora, IA. It’s too fine a material to apply alone with a spinner spreader. It takes a specialized metering type of dry spreader.

We get around that by mixing it 50-50 with ag lime just before spreading with a regular lime application floater truck. This mixing must be done just a few minutes before spreading, as the calcium sulfate reacts aggressively with ag lime. You don’t want a spinner truck full of concrete.

Hatfield was speaking at the summer field day of BRT Ag & Turf. 

USDA’s Agricultural Research Service scientists in Indiana published a detailed fact sheet on benefits of gypsum in 2006.  That data showed a 10-bu. corn yield increase by adding gypsum. You can download the PDF at this link.