Jan. 13,1923 
Effect of Inorganic Nitrogen on Wheat 
63 
RESULTS OF EXPERIMENTAL WORK 
TOTAL, YIELD AND PERCENTAGE OF GRAIN 
The total yield represents the weights of the crops obtained immedi¬ 
ately after they were harvested. The crops were harvested when fully 
ripe and after a continued dry period. The percentages of grain were 
determined in the samples, ranging from iy< pounds to 2 pounds in weight, 
brought to Washington. 
As seen from Table I, the plots which had received nitrogen in any form 
in the first stage gave distinctly higher yields, both as compared with the 
plots which had received no nitrogen and as compared with those which 
had received it in the other two stages. The application of the first 
stage was made later in the season than had been planned, and subse¬ 
quent experiments have shown that the effectiveness of nitrogen with 
respect to increased yields diminishes as the season advances toward the 
completion of the vegetative stage. 5 On the other hand, as a result of 
the lack of uniformity in transition from stage to stage, at the time of 
the second-stage application part of the crops on each plot were still in 
the first stage. This probably accounts for the fact that the plots which 
had received their nitrogen in the second stage as a rule gave higher 
results than those which received it in the third stage. 
The percentages of grain in the crops (Table I) were somewhat lower 
on the plots which had received nitrogen in the first stage than on the 
others. However, the lower range in the percentages of grain would 
not materially alter the grain relationship of the crops. The figures rep¬ 
resenting the total yields, therefore, are expressive of the relative yields 
of grain as well. 
PERCENTAGE OF YELLOW-BERRY 
The result of the lack of original uniformity in the plots, especially 
in those of series B, is most evident in the yellow-berry figures. Never¬ 
theless, the fundamental principle that the application of nitrogen at 
the second stage is most effective in preventing yellow-berry was borne 
out very consistently. The percentage of yellow-berry is the lowest on 
the plots which received their nitrogen at the second stage. A marked 
decrease in yellow-berry is also shown by the crops which received their 
nitrogen in the first stage. This probably is due to the fact that the 
crops did not respond fully in yield because of a late application, and 
part of the nitrogen, applied at this stage and not utilized, remained in 
the soil during the second stage. 
In some cases a somewhat decreased percentage of yellow-berry is 
shown by the crops which received their nitrogen in the third stage. 
This probably is due to the lack of uniformity in transition from one 
stage to another. At the time when most of the heads were in the milk 
stage, some of them had not yet reached this stage. 
No conclusion can be drawn as to the effects of the direct and residual 
physiological acids and alkalies and their neutral salts, owing to the 
general lack of uniformity in the plots, which resulted in a too wide 
range of normal variation as indicated by control plots in both series, 
but especially in series B. Taking into consideration the fact that the 
6 Davidson, Jehiel. the effect of nitrates applied at different stages of growth on the 
yield, composition, and quality oF wheat. In Jour. Amer. Soc. Agron., v. 14, no. 4» P- 118-122. 1922 
