54 The Colorado Experiment Station. 
ANALYSES 
LXIV 
LXV 
LXV I 
Water-Soluble 
Water-Soluble 
Water-Soluble 
laboratory 
laboratory 
laboratory 
No. 590 
No. 595 
No. 981 
Percent 
Percent 
Percent 
Calcic sulfate .. 
. 19.561 
9.102 
3.651 
Magnesic sulfate . 
. 11.236 
8.076 
3.558 
Potassic sulfate . 
. 1.039 
1.034 
Sodic sulfate . 
. 52.457 
56.254 
70.746 
Sodic chlorid . 
. 10.827 
22.609 
16.109 
Sodic nitrate . 
. Trace 
2.771 
4.854 
Sodic silicate . 
. 0.247 
0.308 
Silicic acid . 
0.048 
Loss . 
. (4.633) 
0.880 
— 
100.000 
100.000 
100.000 
Another sample of soil, 826, taken about one mile and a half 
south of No. 981, and a year previous, is interesting because the 
occurrence was a new one at the time. It was on the face of a 
low bank where they had plowed and scraped out dirt in working 
the road. I am quite familiar with this road as it is a section in 
which I have observed the alkali question for going on five years, 
and I feel quite safe in making the statement that the occurrence 
was one which had appeared there within a few months, certainly 
within a single season. I do not know how deep the water table 
was at this place but the land was so high that seepage would not 
ordinarily be thought of; in this case, however, the presence of so 
large an amount of soluble salts, 16.30 percent, will appear to some 
as indicative of a seeped conditon. In this connection I repeat 
again the observation that I have not yet found this condition in 
places where the water table is near the surface of the ground, 
especially if it is permanently near the surface, but in such places 
as have an abundant, but not an excessive, water supply. I do not 
pretend to know all the conditions which are necessary to determine 
the development of these nitrates, but that water is one of the 
conditions is very evident. For in ground that is in good condition, 
with which, ordinarily speaking, no fault can justly be found they, 
the azotobacter, will develop along the margins of irrigating fur¬ 
rows; again, they are apt to develop near a ditch, even on level 
ground, and are especially liable to appear on the outside of a 
ditch bank where the apparently flourish. 
Under the caption of Case No. 8, I have given, it appears 
to me, conclusive proof that neither the alkali, nor the soil, nor 
yet the ground water contained any nitrates, still the outside of a 
ditch bank running beside this land, practically running through 
it, is almost or quite black in color, which color is continuous for 
considerable distances, and the surface soil is decidedly rich in 
nitrates. This color is not due to the wetness of the soil, nor to 
the alkalis, including calcic and sodic chlorid, in the usual use of 
