COLORADO IRRIGATION WATERS AND THEIR CHANGES. 35 
TOTAL SOLIDS IN GROUND WATER BEFORE AND AFTER 
IRRIGATION, JUNE 27—JULY 11, 1898. 
Ground Water. Before Irrigation. After Irrigation. 
Total Solids.. . 5,139.0 9,550.0 
Pounds Gain. 
4,411.0 
Calcic Sulfate..._ 
_ 1,860.2 
2,750.4 
890.2 
Magnesic Sulfate. 
_ 1,238.5 
2,473.5 
1,235.0 
Sodic Sulfate _ _ 
_ 698.9 
3,129.7 
1,430.8 
Sodic Carbonate . __ 
_ 421.4 
515.7 
94.3 
Sodic Chlorid 
_ 560.2 
916.8 
357.6 
Organic Matter, etc. 
_ 360.8 
763.9 
403.1 
Total_ . 
_5,139.0 
9,550.0 
4,411.0 
§ 62. This table is probably too conservative, but it serves 
to show that in this soil the solution of sodic and magnesic sul¬ 
fates takes place in a far greater degree than does that of the 
other salts. The amount of potassic oxid held in solution or in¬ 
volved in the changes produced by irrigation does not seem to be 
very significant. The average amount of potassic oxid extracted 
from this soil by a five days’ digestion with dilute hydrochloric 
acid, 1.115 specific gravity, is 1.25 per cent., or in an acre-foot of 
soil, taking its weight as 3,500,000, we have 43,750 pounds and 
the total potassic oxid in this soil is about 2.25 per cent., or 78,750 
pounds per acre. I have pointed out elsewhere that there is an 
abundance of felspar in this soil and also that dilute hydrochloric 
acid acts very perceptibly upon it, as do also water and carbonic 
acid. The amount of potassic oxid contained in the ground water 
before irrigation amounted to 16.6 pounds in each eight inches of 
water per acre, and after irrigation, 31.7 pounds, an increase of 91 
per cent., or 15.1 pounds. This quantity is apparantly not very 
significant either as an absolute quantity or in comparison with 
that soluble in dilute hydrochloric acid but there is a view in 
which it may be significant. A crop of beets of 14 tons to the 
acre would at maturity contain about 120 or 125 pounds of potas¬ 
sic oxid, or including the tops, 240 to 250 pounds. This repre¬ 
sents the season’s gathering by the plants, but the application of 
eight inches of water has in three days involved an eighth of the 
quantity used by the roots, and one-sixteenth of that used by the 
whole crop in changes whereby it has passed into solution in the 
ground water; it may be a case of simple solution, or the solution 
may have been preceded by other chemical changes, which seems 
exceedingly probable. 
§ 63. In 1899 we had a very much better supply of water 
which we obtained through the kindness of Water Commissioner 
C. C. Hawley; this was water taken from the Poudre but it was 
impossible to prevent the inter-mixing of some seepage water of 
which we shall give as full an account as is required without en¬ 
deavoring to give too many details. The facts concerning these 
waters will appear from the analyses with sufficient fullness and 
further explanations would be tedious to the reader. 
