36 The: Colorado Experiment Station. 
by no means a very bad one, contained 62.2 grains per imperial 
gallon. 
The nitric nitrogen was determined in two of these samples, 
one containing 0.24 part, the other 0.48 part per million, whereas 
No. 610 carried 34.5 parts and No. 792 carried 96.37 parts nitric 
nitrogen per million, or No. 610 carried 143.8 times as much as the 
first drain water and No. 792 carried 200 times as much as the 
second drain water. While the percentage of sodic carbonate in 
the residue obtained from these waters varies greatly, the actual 
amount of sodic carbonate per million of water is nearly the 
same, for instance, 323, 355, and 364 parts per million, which 
serves to show how very high the nitrates in these two waters are 
in comparison with the amounts present in drain waters from 
ordinary alkali land. 
The flow from these drains undoubtedly varies with the irri¬ 
gating season. I do not know whether the drains are stopped up 
or not but they discharged no water for several months during 
the spring of 1911. 
The land included in Orchard No. 13, as stated before, pre¬ 
sents involved conditions. A portion of it was seeped and badly 
so, ten or twelve years ago, and was drained a little over ten years 
ago. This land in the meantime has been benefited to such an 
extent that good crops of wheat, forty-five bushels per acre, have 
been harvested from it. There are portions of this area through 
which the drain passes and which one would think should receive 
the full benefit of the drainage which, though not wetter than other 
portions, are unproductive. I took samples from such places sev¬ 
eral years ago. In taking these samples I recognized three con¬ 
ditions, a thin crust on the surface, of which 8.317 percent was 
soluble in water; a portion immediately underneath this crust, of 
which 7.680 percent was soluble, and the soil proper, the first foot 
of which after the two preceding portions had been removed, gave 
me 1.330 percent soluble in water. 
ANALYSES 
XLV 
XLVI 
XLVII 
Water-Soluble 
Water-Soluble 
Water-Soluble 
Laboratory 
laboratory 
laboratory 
No. 819 
No. 81S 
No. 816 
Crust on 
Portion under 
Soil one 
surface 
the crust 
foot deep 
Percent 
Percent 
Percent 
Calcic sulfate . 
. . . 13.926 
51.858 
19.863 
Magnesic sulfate . 
. . . 20.841 
11.043 
14.511 
Potassic sulfate . 
. . . 2.027 
2.084 
2.611 
Sodic sulfate . 
. . . 44.021 
16.734 
52.334 
Sodic carbonate . 
0.872 
Sodic chlorid . 
. . . 16.427 
16.793 
8.795 
Sodic nitrate .. 
. . . 2.525 
2.435 
1.646 
Iron and Aluminic oxid . . . 
. . . 0.067 
0.032 
0.098 
Silicic acid . 
. . . 0.166 
0.149 
0.142 
100.000 
100.000 
100.000 
