68 o 
Journal of Agricultural Research voi. xxvii. no. 9 
would be precipitated as calcium carbonate. The remaining solution 
would then show higher proportions of the other constituents. It is 
a matter of common observation that underground or drainage waters 
usually show lower percentages of calcium and of bicarbonate than irriga¬ 
tion waters. An example of these comparisons is shown in Table XXV. 
This table gives the composition of irrigation and drainage waters from 
three different irrigated regions. The composition of the irrigation 
water for each region represents the mean of several analyses. The 
drainage water from Newlands, Nev., is reported for two locations. 
One of these, drain Y 13, shows the mean of a series of analyses made 
on the drainage water from the field on the experiment farm which 
had been used for the leaching experiment discussed earlier. The 
percentage of calcium and magnesium in this water is very much lower 
than that of the irrigation water. The actual quantity of calcium is 
greater per unit volume of water, which would indicate that the differ¬ 
ence in composition of the drainage water must be due in large part 
to its leaching action. The soil in the field where this drain is located 
is known to contain large quantities of soluble material the chief basic 
constituent of which is sodium. The water from the Fernley drain 
shows a higher proportion of calcium than that from the drain in field 
Y on the experiment farm. The soil of the Fernley district is known to 
be much more permeable to water than much of the soil of the experiment 
farm, and this condition may be associated with a higher proportion of 
calcium in its soluble constituents. 
Tabi,E XXV. —Comparison of total solids and percentage composition of irrigation and 
drainage waters from several irrigated sections 
Iyocation of sample. 
Total 
solids 
(parts per 
million). 
Constituents as percentages of total solids. 
Ca+Mg. 
CO3+ 
HCOs 
a. 
Cl. 
so*. 
Total acids. 
Newlands, Nev.: 
Irrigation. 
158 
IO. I 
34 *o 
9-5 
23-9 
66. 5 
Drain Y 13. 
3 , 44 ° 
1-3 
23.6 
6. 0 
28.0 
57-6 
Drain, Fernley. 
2, 720 
5-6 
6.9 
8.4 
49- 5 
64.8 
Huntley, Mont.: 
Irrigation. 
278 
17.8 
24. 0 
5-6 
32.0 
61 . 6 
Drain 13. 
5, 860 
7.8 
3-7 
1.4 
58.4 
63-5 
Bard, Calif.: 
Irrigation. 
960 
17 - 3 
14- 5 
11 . 2 
37.8 
63- 5 
Field wells. 
1,095 
13-8 
12. 9 
! 5*3 
37-3 
65-5 
The comparison of the irrigation and drainage waters from the Huntley 
project shows that the drainage water contains lower proportions of the 
earthy bases, calcium and magnesium, than the irrigation water and 
also much less carbonate and chlorin. The indications are that in per¬ 
colating through the soil it is taking up substantial quantities of sodium 
and sulphate. On both the Newlands and Huntley projects the drainage 
water is much more concentrated than the irrigation water, carrying 
15 to 20 times as much dissolved material. 
The waters reported from Bard, Calif., were taken on the Yuma 
project, which is irrigated from the Colorado River. On this project 
much of the irrigated land is underlain by a saturated zone that is directly 
