6 
Colorado Experiment Station 
physical properties of the wheat. This establishes the inference drawn 
from the uniformity of the results obtained in the use of nitric nitrogen, 
i.e., that the results observed were the specific effects of the nitrogen 
in the form of nitrates and not of organic nitrogen. Nitrogen in the 
form of ammonia has been shown by Ritthausen and Dr. R. Potts to 
produce the same efifects that the nitrates do. The nitrogen in the 
ammonia salts, when these are applied to the soil, is readily converted 
into the nitrate form so their effects are really the effects of nirrates. 
HARDNESS OR SOFTNESS DEPENDS ON RELATIVE SUPPLY OF 
NITROGEN IN THE FORM OF NITRATES 
The cjuestion of the properties of our whaets whether they are 
hard or soft, flinty or mealy, depends upon the relative supply of nitro¬ 
gen in the form of nitrates. If the supply of these in the soil is in the 
right proportion to the supply of potassium our wheat will be all that 
anyone could desire. It will be large-grained, plump and flinty, which 
is to say rich in protein. 
The amount of nitrogen in our soil is not a fixed quantity but 
varies from time to time both in the total amount present and in the 
portion of it which may be present in the form of nitrates. Experi- 
'mental proof has been adduced in preceding bulletins that in contiguous 
areas of i scpiare foot the total nitrogen as well as that in the form of 
nitrates not only may, but actually does vary by significant quantities. 
Data obtained, both by laboratory experiments and on a larger scale in 
imitation of field conditions, establish it as an easily demonstratahle 
fact that the soil in which we grew our wheats varies in its amount of 
total nitrogen from time to time. To establish this we made observa¬ 
tions on 3,000 pounds of soil taken from the field and found that we 
had a maximum increase of 62 pounds per million of soil and that while 
the total nitrogen varied, it at all times showed an increase over the 
amount present at the beginning of the experiment. At the end of 
40 days the total amount of nitrogen present exceeded that present at 
the beginning by 36 pounds per million. The nitrogen present as ni¬ 
trates at the end of this experiment exceeded that present in this form 
at the beginning; by 15.70 pounds per million. The increase in total 
nitrogen is due to fixation and the increase in the form of nitrates 
shows how actively the process of nitrification was going on. The 
3,000 pounds of soil made a bed, as we prepaerd it, 6 inches deep 
Other and fuller data on the increase of the nitrogen present as 
nitrates will be found in Bulletin No. 217, pp. 42 and 43. 
The significance in the increase of the total amount of nitrogen is 
that it is sufficient to maintain a reasonable supplv and beyond question 
is present as living organisms, suscentible of rapid changrs. The nitric 
to the wh-cet ‘'B.nt a-.il th.e cmv.Nitv 
nitrogen is directly availr.h'c 
