
FIELD EXPERIMENTS WITH FERTILIZERS. 183 
The methods for distinguishing between proteid and non- 
proteid nitrogen are not satisfactory. We nevertheless hope 
at some future time to inquire into the quantities of proteid 
and non-proteid nitrogen in the plants grown on the different 
plots in these experiments, even though there is little reason 
to believe that the results will prove of special importance. 
Had the resources of the Station allowed it this would have 
been done already. 
In view of the possibility of the occurrence of nitrogen in 
the form of nitrates a number of tests were made for nitric acid 
in samples of crops from plots on which the nitrogenous fertil- 
izers were applied, but the results of the tests were negative, 
as stated on page 174. 
From the figures in these tables it will be noticed that in 
many instances the percentage of protein is higher in crops 
grown with no fertilizers than it is in crops grown with fertil- 
izers. This same thing has been observed in previous experi- 
ments, and is explained in former Reports* as probably due to 
the fact that in the grain grown without fertilizers there is a 
large proportion of ‘‘ poor’’ or ‘‘soft’’ kernels. These latter 
have been shown by analysis to contain a larger perceutage of 
protein than is found in matured corn, owing possibly to an 
incomplete development of starch and oil in the immature seeds. 
In the crop from sections of the mineral plots (6a and 64) the 
percentages of protein are seen to be in nearly all cases smaller 
than in the crops from sections of plots with nitrogen. In 
plants from the nitrate of soda group of plots the percentages 
of protein were largest in both grain and stover from sections 
of plot 9. The increase, however, in the protein in the crops 
from sections of plot 9 over that in the crops from sections of 
plot 8 did not correspond in all cases to the increase in the 
quantity of nitrogen in the fertilizers. In many instances the 
percentage of protein in crops from sections of plot 9, with 
seventy-five pounds of nitrogen per acre, are but little larger 
than in those from sections of plots 8 or 7, with fifty or 
twenty-five pounds. of nitrogen per acre. Similar facts are 
noticed in the results from the sulphate of ammonia group of 
plots. 

* See p. 28 of the Report of this Station for 1890; also p. 136 of Report for 1898. 
