Gypsum vs Calcium Sulfate Anhydrite
Art Wilson Company Provides Additional Information on Calcium Sulfate: To read the report provided to PACE Turf by Art Wilson Company click on the link below:
http://www.paceturf.org/PTRI/Document...
Use of gypsum in soil applications and water treatment is a standard practice for managing soil sodium. There is some confusion, however when it comes to selecting gypsum products because there are many different products being marketed for sodium management - some of which contain gypsum and others that do not.
In this video, we look at products based upon gypsum and products based on a related material- calcium sulfate anhydrite - and we explain why their very different performance when dissolved in water is important when making your product selections.
For a printed report that describes the techniques used in this video in more detail, see this Super Journal article on gypsum vs. mined calcium sulfate anhydrite:
http://www.paceturf.org/index.php/jou...
For information on labeling of gypsum products in California, refer to: California Department of Food and Agriculture, Feed, Fertilizer, and Livestock Drugs Regulatory Services Notice of Fertilizer Licensees. Subject: Labeling of Gypsum Products. Labeling requirements for gypsum pursuant to Section 2302(i)(4) of the California Code of Regulations (40 KB pdf):
http://www.paceturf.org/PTRI/Document...
To evaluate dissolution rates, we utilized the following constant: 1 meq Ca/l = 0.085 dS/m (Carrow,R.N., Waddington,D.V., and Rieke, P.E. 2001. Turfgrass Soil Fertility and Chemical Problems. page 152.)