No4ajl ^ 1 ^ 3 ^ 
AS, here, and usually understood, fertilizers include the so-called artifi- 
jfx cial, or chemically prepared, commercial fertilizers, but not manure, 
the latter being mostly of animal origin. 
Many intelligent gardeners often ask why use commercial fertilizers at 
all, considering that it is only since the rise of industrial chemistry that they 
have been available. This is true, and if manure in sufficient quantities could 
be found, chemical fertilizers would not be needed. But the motor age and 
the passing of the horse have made animal manure 
No 
Sulphur 
No 
Iron 
No 
Boron 
rather scarce and really quite expensive when you 
consider the amount it takes in order to get the same 
results that a small amount of commercial fertilizer 
will give. 
Before coming to specific fertilizer suggestions for 
different crops, it will make them more intelligible 
to understand and the role of the constituents. 
Nitrogen. The most valuable, most expensive, 
and soonest exhausted of all fertilizer constituents. 
It is necessary for leaf growth and in general, all 
plant growth above the ground. Large amounts pro¬ 
duce a rank, tender growth of a dark green color. 
The quickest-acting and most effective source of 
nitrogen is nitrate of soda. It is available almost as 
soon as applied to the ground as it dissolves at the 
first rain and is immediately available. Its disadvan¬ 
tage is that, once applied, it is soon lost (absorbed 
by the crop) and consequently builds up little or no 
residue of nitrogen for later crops. But other sources 
of nitrogen will supply this deficiency. 
One of them is bone meal. This ground-up bone 
dust dissolves much more slowly than nitrate of soda 
and is consequently of value in small gardens, as 
top dressing for pots, frames, or for feeding house 
plants. And because of its slow action, it is safer to 
use than nitrate of soda, an overdose of which can 
easily injure or even kill a crop. Bone meal also 
contains much phosphoric acid. 
Other valuable sources of nitrogen are tankage and 
dried blood, both prepared by-products of the 
slaughter houses, and, like bone meal, more useful 
for permanent enrichment than for quick effects. 
Calcium nitrate, sulphate of ammonia are also valu¬ 
able sources of nitrogen. 
Phosphoric Acid. This, mostly supplied by rock 
phosphates and superphosphates, is, next to nitrogen 
in importance. Its especial function is the stimula¬ 
tion of cereal crops, but it is also absolutely neces¬ 
sary for most vegetable and flower crops. Many soils 
are deficient in phosphorus and the lack of it often 
slows up final crop production. Phosphoric acid 
causes the development of fibrous roots, increases 
disease resistance, and hastens maturity. 
Potash. The chief use of potash is the stimulation 
of root crops like beets, carrots, turnips, radishes, 
and parsnips. But as part of the balanced ration for 
perfect growth, potash must be a constituent of all 
fertilizer mixtures. It is used chiefly in the form of 
muriate of potash for vegetables, and sulphate of 
potash for potatoes. Wood ashes contain from 4 to 6 
percent of potash. 
Potash is necessary for the formation of starch 
and its transference to various parts of the plant. It 
also increases resistance to disease. All crops require 
potash for proper growth, but it is especially valu¬ 
able for cabbage, celery, and the root crops. 
While different plants need different amounts of 
these three substances, only a “straights” (such as 
nitrate of soda) are applied alone, and this where 
special crops are being raised in soils definitely 
lacking in one element. Most fertilizers contain judi¬ 
cious mixtures of the three, hence the common ad¬ 
vertising of so-called “complete fertilizers.” 
Aim No No 
Elements Phosphorus Potassium 
A complete fertilizer should theoretically contain all the plant food that 
could be derived from a perfect soil. But plants use so many different 
chemical elements and their compounds, and so many of them are present 
in more than adequate amounts in all soils, that a complete fertilizer is now 
understood to contain the three most essential elements only—^nitrogen, 
phosphoric acid, and potash. It is upon these three, especially nitrogen, that 
the fertility of most soils depends, and all commercial fertilizers contain 
these substances in varying ratios, depending upon the crop and the soil to 
which the fertilizer will be added. 
No one today needs to buy fertilizers blindly. They are forced to contain 
a specified amount of available nitrogen, phosphoric acid, and potash, and 
their claims are checked by the chemists of the Department of Agriculture. 
The uninitiated, however, can still be misled, or can buy fertilizers 
wastefully, by not understanding exactly what the figures on a fertilizer 
bag means. It is, for instance, a common thing to see a bag labeled 4-12-4, 
or almost any other combination of three numbers separated by hyphens. 
Throughout the United States such figures always mean that the first figure 
is the percentage of nitrogen, the second the percentage of phosphoric acid, 
and the third the percentage of potash, in the mixture. 
No No No 
Nitrogen Calcium Magnesium 
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