COMPUTATION OF FERTILIZER MIXTURES 5 
A material such as sodium nitrate, in which the NH 3 amounts to 
100 per cent of the fertilizing elements present, will be represented 
on the triangle by the point A. Similarly, acid phosphate will corre- 
spond to the point B, and a potash salt to the point G. As the lines 
joining these three points coincide with the boundary lines of the 
triangle, it follows that submultiples of any fertilizer ratio whatever 
may be made by combinations of these three materials. The maxi- 
mum fertilizer analysis formula possible for any given ratio is obtained 
bv multiplying by the factor ~ v „ . Thus, if the sodium nitrate 
contains 18 per cent NH 3 , the acid phosphate 16 per cent P 2 5 , and the 
potash salt 20 per cent K.,0: then, for a 4-8-4 mixture, X = 444, Y = 
1000, Z = 400, and X+Y+'Z = 1844. The maximum possible analysis 
formula, corresponding to the mixture 4-8-4, that can be made from 
[9000 "1 
^g(4-8-4) or 4.34-8.68-4.34. 
A material, for example a tankage containing, say, 8.5 per cent 
NH 3 and 5 per cent P 2 5 , would have 63 per cent of its fertilizing 
elements in the form of NH 3 and 37 per cent as P 2 5 , and would be 
represented in the triangle on the side AB by the point F. Sub- 
multiples of all ratios which fall within the triangle FCB can therefore 
be made from this material in combination with acid phosphate, 
and a potash salt, while those which fall outside this triangle, such 
as the analysis formula 5-2-3 corresponding to the ratio 50-20-30 
represented by the point G, can not be made. G, however, falls 
within the triangle FOA, and, therefore, submultiples of the ratio 
50-20-30 can be obtained by combinations of tankage and potash 
salt with a nitrogenous material. 
If the ammonia in a fertilizer mixture is to be obtained from nitrate 
of soda, cottonseed meal, and tankage, in the proportions given in 
Table 2, then 2 of a total of 4 parts of NH 3 will be present in the 
mixture as nitrate, 1 as cottonseed meal, and 1 as tankage. But 
the quantities of the two last materials, which contain 1 part each 
of NH 3 , also contain 0.96 part of P 2 5 and 0.23 part of K 2 0. The 
mixture of these three materials therefore contains 77 per cent of 
the fertilizer constituents as NH 3 , 19 per cent as P 2 5 , and 4 per 
cent as K ? 0, and may be represented in Plate I by the point H. 
Submultiples of all ratios which fall within the triangle HBO can 
be made by combinations of these three materials with acid phos- 
phate and potash salt. The maximum fertilizer analysis formula 
that can be made of any of these ratios is obtained in the usual way 
by multiplying by the fraction x+X' + X"+Y + Z ' 
FACTORS THAT INFLUENCE THE CONCENTRATION OF 
FERTILIZERS 
The principal sources of each of the three essential constituents of 
fertilizers are saline or mineral deposits and industrial by-products. 
Phosphate rock is the principal source of phosphoric acid, but the 
latter also occurs in bones, fish scrap, and cottonseed meal. The potash 
comes from saline and mineral deposits, and industrial wastes such 
as cement-mill dust, tobacco stems, and sugar-beet liquors. The 
nitrogen is obtained from even more diverse sources such as the 
nitrate deposits of Chile and the waste products of many industries. 
