A Study of Colorado Wheat 
6i 
EFFECTS OF FERTILIZERS ON THE THICKNESS OF THE BRAN 
It is usual to take the nitrogen content as the principal criterion 
in judging the differences in wheat. The other constituents usually 
given in an anailysis, moisture, ash, fat, fiber, and even starch, are of 
much less importance. The crude fiber as determined in the wheat 
corresponds roughly to the epidermal portions of the wheat, and in a 
rough way indicates the relative thickness of these parts. It might be 
interesting from an anatomical standpoint, to know whether the fer¬ 
tilizers influence these protective features of the grain or not, and how, 
but for our purposes these points are not of much interest and the re¬ 
sults of the 36 analyses of wheat grown on our own plots, presented 
in the preceding tables, indicate nO' decisive and constant difference. 
The range of these determinations in the 36 samples is from 2.400 to 
3.007 percent, or a maximum variation of 0.607 percent. The average 
percentage of crude fiber in the samples grown with application of 
nitrogen is, taken literally, the least of the four averages and that of 
those grown with potassium, the highest. The difference is 0.12 per¬ 
cent, too small for consideration from our standpoint. The starch, 
owing ten its large percentage, will reflect the variation in the protein, 
the substance present in the next largest quantity; these two substances 
present in wheat in the largest quantities must bear an inverse relation 
to one another. There is nothing in our analyses to show that this is 
anything more than a numerical relation. If there be any other rela¬ 
tion between these substances it is not shown bly our results so far 
given. The formation of starch or carbohydrates, in general, may 
influence that of the protein or vice versa, but this is a physiological 
relation which our work does not present. The question of flinty and 
mealy kernels probably comes within the province of this relation. We 
have shown in Bulletin 205 that this is directly a question of the ratio 
between the nitrogen and potassium present in the soil and available 
to the plant. The ash in the analyses given was determined by the 
usual method of incineration, i.e., charring, extraction with water and 
subsequent ignition. There is no question but that some loss occurs 
in this method, but not enough to vitiate the results. The nine sets of 
samples agree in showing that those grown with the application of 
nitrates are a little lower than the others. This will be found to be the 
rule, but it is not altogether without exception. It is owing to diffi¬ 
culties in preparing the ash of grain and also of the straw that I have 
used the form ‘‘ash-constituents” in stating the analytical results of 
such determinations for both wheat-straw and grain. Leavitt and 
Le Clerc * have showri that there may be a very considerable loss of 
phosphorus in direct calcination. They found the difference between 
incineration at low redness and “redness” to equal 46.0 percent of the 
* Journal Am. Chem. Soc., Vol. 30, pp. 391-394. 
