Potash
J.E. Shields (Wed, 07 May 2008 16:14:59 PDT)
Jim McK.,
I'm happy to oblige. What we are seeing here is cultural (not to mention
scientific) lag. Using "potash" in place of the proper name for the
element, potassium, is left over from the 18th century. Which seems to be
about where some horticulturists and all gardening magazines still
reside. (Ouch!)
The terms "sulphate of potash" and "muriate of potash" are simply archaic
names for potassium sulfate and potassium chloride. There is no "potash"
(K2O) hidden in the sulfate. Personally, I have a heck of a time figuring
out what the N-P-K numbers ought to be for chemicals like potassium
nitrate, ammonium phosphate, etc. When I mix my own from lab chemicals, I
end up with the metric numbers, not the silly American fictions.
You can tell the difference between cheap and premium fertilizers by
reading that fine print. If they use potassium chloride (KCl) as the
source of potassium, it's cheap stuff. If they use sodium phosphate, it is
even worse quality (and even cheaper).
Jim, I'll go off on a tangential rant if I don't quit now! If you have any
more questions, drop me a note later.
Best to all,
Jim Shields
ranting and raving in central Indiana (USA) over the scientific illiteracy
of certain parts of the world
At 06:32 PM 5/7/2008 -0400, you wrote:
Jim Shields, if you don't mind, let's continue the inorganic chemistry
lesson.
If, as you say, potash is literally the potassium containing residue of
burned wood, are there such things as sulfate of potash and muriate of
potash? And if so, are they different in some way from potassium sulfate and
potassium chloride? I'm not asking you if the names exist - we already know
that these terms are common, at least in the older gardening literature. I'm
asking if there is such a thing as sulfate of potash which is distinct from
potassium sulfate and a muriate of potash which is distinct from potassium
chloride.
.......
Jim McKenney
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Jim Shields USDA Zone 5 Shields Gardens, Ltd.
P.O. Box 92 WWW: http://www.shieldsgardens.com/
Westfield, Indiana 46074, USA
Tel. ++1-317-867-3344 or toll-free 1-866-449-3344 in USA