The Florida agriculturist. [volume] (DeLand, Fla.) 1878-1911, 1907-04-24

Union, in which SO many tons of
commercial fertilizer are used in pro-
portion to the area Of soil cultivated
as IN Florida. 1t is therefore impor-
tant that the value of the various in
gradients and special fertilizers
should be understood, SO that it may
be used as economically as possible.
The following article is one of a
series which is being published by
the American Agrlculturlst, and we
think that you will find it interesting
and valuable:
Commercial fertilizers are complete
when they contain nitrogen, phos-
phoric acid and potash; and incom-
plete when they contain only one or
two of these ingredients. The term
chemicals is usually applied to nitrate
of soda, sulphate OF ammonia, muriate
and sulphate of potash and similar
materials. In most states laws re-
quire manufacturers to furnish the
amount of each constituent guaran-
teed to be present in the fertilizer.
Nitrogen is stated as nitrogen or am
mon1a. The use Of ammonia is mis-
leading, because few commercial fer
tilizers contain any nitrogen in the
form of ammonia.
Frequently the term, bone phos-
plate of lime, is used simply for the
purpose of making the amount Of
phosphoric acid appear larger than it
IS, since one pound Of phosphor1c
acid is equal to about two pounds OF
bone phosphate of lime. Potash
should always be given as potash, but
sometimes the amount is given as sui
phate because the figures are then
about twice as large as when the
amount is given as potash. When the
terms ammonia, bone phosphate OF
lime and sulphate Of potash are given
in fertilizer guarantees, the purpose
is to mislead and make the consumer
think he is getting more plant food
than is present. Therefore, in eX
am1n1ng a guarantee, one should pay
no attention to any Of the forms
used except nitrogen, available phos
phoric acid and potash, and require
the guarantee to be in these terms be-
fore purchasing.
The belief is very general that all
fertilizers consist in large part OF
high-grade fertilizer Analysing tour
per cent. nitrogen, ten per cent. phos-
phoric acid, and ten per cent. potash,
appears to contain only "a pounds OF
plant food in 100 pounds. The ques-
ton arises as to what the remaining
70 pounds consist Of We cannot use
fine nitrogen or phosphorlc acid or
potash in fertilizer; we must use their
compounds, which we may think of
as diluted forms. For example, in 100
pounds blood we have only about 10
pounds nitrogen; in 100 pounds acid
phosphate, IA or IS pounds phosphor1c
acid; in 100 pounds kainit, II OF. IS
pounds potash. In fertilizers OF low
grade, inert, valueless materials may
High-grade fertilizers do not permit
the use of much, if any, filler.
Figuring value of unmixed mater1-
als.SIn Comparing the values of diff
ferent commercial fertilizers, one NAV
usually reach quite a helpful conclu-
sion by figuring the value of the un-
mixed materials. The following sim
Die rule NAV be used satisfactorily for
approximate results: Multiply the per
cent of nitrogen by three and add to
the product the figures representing
the per cent of available phosphor1c
acid and of potash. The same ex-
presses in dollars and cents the ap..
proximate commercial valuation OF
the fertilizer.
Examples: I. What is the COM
mercial valuation of fertilizer an
alyzing z per cent. nitrogen, eight per
cent. phosphoric acid, and three per
cent. potash? (2x3) plus 8 plus 8
Sly. T. Analysis, four per cent. nj
trogen, eight per cent. phosphorlc
acid and ten per cent. potash? (4x0
plus 8 plus 1870. These figures DO