A Study of Colorado Wheat 
35 
THE EFFECTS OF FERTILIZERS AS INDICATED BY THE NITROGEN 
CONTENT OF THE PLANT. 
The data previously given lead to the questions suggested by 
this caption. The most important questions that present themselves 
in our work during a given year pertain to the part played in the 
nutrition and development of the plant by the inorganic constituents 
available in the soil. Perhaps we should consider the absolute sup¬ 
ply and the ratio of the respective substances. 
The climatic influences for any given year are eliminated by 
the fact that they are the same for all series of experiments made 
during that year and our varying results in the different individual 
experiments cannot be attributed to the differences in this respect. 
All will agree that nitrogen is the inorganic constituent of the soil 
most easily traced during the development of the plant and at the 
same time the most important one both directly as a plant food 
and indirectly by its influence upon the appropriation of other ash 
constituents, and also upon the subsequent processes within the 
plant, depending upon the relative quantities of these present. In 
order to follow these processes we adopted the nitrogen content and 
its various forms, tl^e amino group excepted, as the criteria whereby 
to judge of the influence of the nitrogen applied in the soil. It is 
our intention to try to follow these throughout the development of 
the plant from the time of bloom till the wheat is ripe and even into 
the flour. In order to accomplish this purpose we shall give the 
total nitrogen, the proteid nitrogen, the nitrogen present as am¬ 
monia and as amid. 
We omit the amino-group in our analysis of the plant because 
we judge it, from our experience with the beet plant, to be of little 
significance and its determination as involving such large errors as 
to be of doubtful value. 
The forms of nitrogen determined are given in the tables that 
follow. The variety studied was the Red Fife. We were com¬ 
pelled to confine our efforts to the one variety for the simple rea¬ 
son that we could not do any more samples while they were fresh 
and before there could be any question of material changes. In all 
cases in which the green samples had to stand, even for a few 
hours, we chloroformed them heavily. 
A number of determinations were made, using the whole plant, 
but we found it quite impossible to obtain good agreement in the 
results because of variation in the samples as weighed out. 
