When you add the three numbers,
it totals 60.
So 60 % of this bag is nutrients,and 40 % is Filler.
You would get the same
nutrient ratio with 5-10-5 or 1-2-1,
but you would be buying Much more filler.
The United States Department of
Agriculture (USDA) mandates that products sold as soil nutrients must
have
their minimum essential plant nutrients displayed prominently on the
container
(by percentage of weight). The order is: Nitrogen (N), Phosphorus (P)
and
Potassium (K). If a fourth number is present, it represents
Sulphur,
which is beneficial to acid-loving plants like Azalea,
Rhododendron, Hydrangea, and Blueberries.
A ratio for "average" plants
is 3-1-2, which is the same ratio as 6-2-4, or 12-4-8.
These ratios (by weight) mean
that 100 pounds of 3-1-2 contains at least
3 pounds of Nitrogen, 1 pound
of Phosphorus, and 2 pounds of Potassium.
6 pounds of Nitrogen, 2 pound
of Phosphorus, and 4 pounds of Potassium
are contained in 100 pounds
of 6-2-4 (at least). The other 88 pounds is "filler".
If you could find 50-17-33,
the ratio would be virtually the same.
But there would be no filler.
It takes only 50 pounds of 6-2-4
to get the same benefit as 100 pounds of 3-1-2.
The higher concentrations may
cost more, but may be cheaper in the long run, since less is used to
obtain
the same benefit. So if 40 pounds of 3-1-2 costs $5.00, then anything
less
than $10.00 for 40 pounds of 6-2-4 is the bargain.
Fertilizer Numbers
