Agriculture Reference
In-Depth Information
Sulfur
Sulfur is important, and lacking in many soils, which is one reason why gypsum is often
recommended along with calcitic lime. Like nitrogen, sulfur is a major component of pro-
tein, and its presence helps nitrogen to be used more efficiently. Sulfate can enhance calci-
um availability and is used by plants in several ways.
Gypsum, discussed in the calcium section of the last chapter, is the way to go for organ-
ics. I don't tend to use elemental sulfur because it can create sulfuric acid, tie up calcium
and cause your fruit to rot at maturity, but some people use it successfully. Langbeinite, po-
tassium sulfate and epsom salts, all discussed previously, contain sulfur, too. We're looking
for a 1:1 potash to sulfate ratio on a Reams test.
Sulfur bonds to excess cations and leaches them, provided there is sufficient calcium. It
will bind with calcium, magnesium, potassium and sodium, and then water will leach some
of it down. I use an appropriate form of sulfur when a soil test indicates I have too much of
one of the cations. Using the right form of sulfur helps to kick the calcium, magnesium, po-
tassium and sodium toward their appropriate numbers.
The form of sulfur you add depends on which cation is in excess. If calcium is low and
magnesium is high, gypsum (calcium sulfate) is often included in a fertility program, often
at 10 pounds per 1,000 square feet. If calcium is high and magnesium is low, epsom salts
(magnesium sulfate) would be added. If calcium or magnesium is high and potassium is
low, potassium sulfate would be added. If sodium is high, choose the best for your situation
from any of the above.
