8 The Colorado Experiment Station. 
half feet deep at the same place, where we dug to the depth of five 
and a half feet on November 3. At this depth the ground was 
very wet, even muddy. We waited a short time to see whether 
any free water would flow in but it did not. On May 14, 1910, 
I again visited this orchard. The condition of the orchard was 
very bad, many trees had been removed and many more were 
dying. On June 11, 1910, almost exactly a year subsequent to 
the first observations made on these dying trees, I visited it again. 
The orchard was ruined; most of the trees were dead; and worse 
yet, the land, so far as we can now see, is as thoroughly ruined 
as the orchard. A large portion of this orchard—six to eight 
acres—has been dug up. 
The orchard immediately south of this one is in a very bad 
condition; it is, for the most part, dead. No samples of either the 
soil or the ground water were taken at this place. The owner, a 
man of considerable education, is fully convinced that the trouble 
is not due to excessive water in the soil. 
The following samples of surface soil from Orchard No. 5 
will convey a better idea of the conditions existing in this soil than 
any words describing them. In No. 947-a the water-soluble equalled 
11.6; in No. 959, 3.4; in No. 995, 12.79, and in No. 1013, 7.20 
percent of the air-dried soil. 
ANALYSES 
II 
III 
IV 
V 
Water-Soluble 
Water-Soluble 
Water-Soluble 
Water-Soluble 
laboratory 
Laboratory 
Laboratory 
Laboratory 
No. 947a 
No. 159 
No. 995 
No. 1013 
May 14, 1910 
June 11, 1910 
Aug. 25, 1910 
Sept. 13, 1910 
Percent 
Percent 
Percent 
Percent 
Calcic sulfate. 
. 18.437 
20.437 
8.219 
9.123 
Calcic chloricl 
14 778 
17.005 
20.415 
Magnesic sulfate . 
5.999 
. 10.474 
12.295 
10.658 
Magnesic chlorid . 
Potassic sulfate. 
1.447 
• 
. 2.273 
1.434 
1.575 
Potassic chlorid. 
Sodic sulfate . 
15.104 
Sodic chlorid . 
. 13.726 
35.416 
8.747 
27.708 
Sodic nitrate . 
. 39.790 
21.303 
52.071 
30.350 
Iron and Aluminic oxids 
. 0.132 
0.149 
0.090 
0.051 
Silicic acid . 
. 0.210 
0.235 
0.139 
0.111 
100.000 
100.000 
100.000 
100.000 
The dates on which the various samples were taken, extending 
over two years and representing the months of May, June, August, 
September and November, show that the condition is a persistent 
one, and while it may vary from month to month there was a very 
dangerous quantity of nitrates in this soil throughout the whole 
period. 
I11 1909 I produced decided injury to four-year-old trees by 
the addition of five pounds of nitre to the soil, within a radius of 
