VOLUME L . NUMBER 1 
BOTANICAL —CCAZETTE 
JULY Toro 
RATIO OF PHOSPHATE, NITRATE, AND POTASSIUM 
ON ABSORPTION AND GROWTH? 
OSWALD SCHREINER AND J. J. SKINNER 
(WITH NINE FIGURES) 
In this paper are reported the results of experiments obtained 
in connection with a study of the effects of harmful soil constituents 
upon plant growth and upon soil solutions and fertilizer action. 
The results here reported are especially with reference to the growth 
made by wheat seedlings in culture solutions containing many differ- 
ent ratios of phosphate, nitrate, and potash, and in regard to the ratio 
of these constituents originally present and removed by the wheat 
seedlings in the course of the experiment. In these investigations 
solution cultures containing the three fertilizer ingredients, namely 
P,O,, NH,, and K,O, as calcium acid phosphate, sodium nitrate, and 
potassium sulfate, respectively, in all possible ratios of one, two, and 
three constituents, varying them in stages of 1o per cent, were prepared, 
the concentration being 80 parts per million in these constituents. 
The selection of the salts as carriers of phosphate, nitrate, and 
potash, and the statement of the results in terms of P,O,, NH,, and 
K,O, are in harmony with the practice in fertilizer work and, for the 
sake of simplicity, these designations are also retained in the present 
paper. The salts selected, it will be seen, are also carriers of calcium, 
of sodium, and of sulfate, and the three salts, therefore, are the best 
that could be selected for giving at the same time other needed 
constituents. | 
The culture solutions of these three salts contained in each case 
a total concentration of 80 parts per million of P,O,, NH,, and K,! a8 
* Published by permission of the Secretary of Agriculture. ee 
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