Agriculture Reference
In-Depth Information
Gypsum (22% Calcium and 17% Sulfur)
Gypsum is calcium sulfate. I'm not referring to drywall, which contains ingredients that
are toxic to plants, nor the chemical version of calcium sulfate, which also shouldn't be
used. Gypsum is a sedimentary rock that is fairly common and is mined in many places. It's
in the same price range as calcitic lime.
The sulfur is in the sulfate form containing one sulfur molecule and four oxygens, read-
ily available to plants. I use it for the sulfur when I need it. And I use it very often as a cal-
cium source along with calcitic lime and soft rock phosphate. It helps bring more oxygen
into an anaerobic soil, so it's even used when calcium is adequate.
