A Study or Colorado Wheat 
i3 
easily demonstrated. Finely powdered felspar will yield potash to 
growing plants, as I have proved, using the oat plant. 
We have not only grown oats in powdered felspar to maturity, 
with the production of seed, but we have taken our ordinary felspar 
and treated it just as we do soil samples with citric acid solution and 
with water to see how much phosphoric acid and potash it will yield 
to these solvents. Our results indicate that quite as much of these 
substances maybe dissolved out of pure undecomposed felspar as out 
of our soils by a similar treatment. Felspar crushed to pass through 
a 60-mesh sieve yielded to a one-percent citric acid solution from 
0.015 to 0.030 percent of phosphoric acid and from 0.018 to 0.051 
percent of potassic oxid. The action of pure water, distilled water, 
on pulverized felspar is sufficient to become a factor in our soil 
problems. 
The results in the preceding experiments led us to test the solu¬ 
bility of finely ground apatite in like manner. Apatite ground to 
pass a 100-mesh sieve yielded to one-percent citric acid 2.25 percent 
of phosphoric acid and to water 0.042 percent. A blank test made 
with the citric acid solution showed only an exceedingly minute trace 
of either phosphoric acid or of potash. 
The mineral basis of our soils, according to these results, may 
play an unusually important part in our questions. Both the coarser 
and finer portigns of this soil are composed largely of particles of fel¬ 
spar in a comparatively fresh condition, but according to the above 
results, they may serve as a source from which phosphoric acid and 
potash may be continuously supplied. It will be noticed that the 
mass analyses of the soil and subsoil give higher results than the 
analyses with hydric chlorid, specific gravity 1.115. This is prob¬ 
ably due to the fact that the coarser portions of the felspar are 
large enough to protect the apatite contained in them from the 
action of the acid. 
The moisture as well as the nitric nitrogen in the soil varies 
greatly. Both of these were determined from time to time 
throughout the season of 1913, and we intended to follow them 
throughout the season of 1914, but our working force was not 
large enough to do this and some of the field work done in 1913 
could not be done in 1914. I would have preferred to have carried 
out the same schedule of investigation through the whole period 
of our field experiments, but we could not and I am not sure that 
we would have gained anything by doing so; concerning this, how¬ 
ever, there may be room for difference of opinion. 
NITRIC NITROGEN AND ITS DISTRIBUTION. 
The caption states exactly what we intend to present in this 
section of our work as best we can. While the greater part of the 
