46 
The Colorado Experiment Station. 
A sample of the surface soil was taken from that portion of 
the field represented in Plate III immediately in front of the 
pei son who is actually holding* the sample. This sample was 
taken only to a very shallow depth, scarcely more than one inch; it 
yielded to water 8.83 percent after being thoroughly well air-dried. 
ANALYSIS 
Calcic sulfate . . 
Calcic chloricl . . 
Miagnesic chlorid 
Magnesic nitrate 
Potassic nitrate 
Sodic nitrate . . 
Silicic acid .... 
LVI 
Water-Soluble 
Laboratory 
No. 1012 
Percent 
.. 5.941 
. . 26.566 
. . 4.469 
. . 21.527 
. . 4.107 
. . 37.269 
. . 0.121 
100.000 
Case No. 17 The trouble in this orchard came to my notice 
for the first time in July, 1910. Inquiry elicited no satisfactory 
information relative to the presence of any burning of the leaves 
during the preceding year. I, however, became fully convinced 
ot one thing, namely, that while it is very probable that the trouble 
was present in 1909, even to the extent of killing a few trees, it 
was not so general as it became during the early part of the season 
of 1910. 1 he location of this orchard is very favorable; the soil 
is of the best quality and the drainage is excellent. The red mesa- 
soil is uniform in appearance and texture for a depth of four and 
a half feet, when it changes to a gravel as shown by a hole dug bv 
a badly burnt tree. The land had been irrigated probably a week 
pnor to the date on which I dug this hole and took my' samples. 
W e found, however, no excess of water in the soil. The irrigating 
water, if it had at any time made a portion of the soil excessivelv 
wet, had already drained out to such an extent that the soil was 
no more than in good condition, even the foot of soil next to the 
gravel was not excessively wet, perhaps between twenty and 
twenty-five percent of its weight being water. This orchard con¬ 
sisted of a younger and an older part. The burning was in most 
cases very moderate, so moderate that one would be surprised if 
the lesult should be fatal unless the soil conditions should °*row 
worse. A few trees had already died from this cause, though there 
were other dead trees with girdled crowns to which their death was 
probably attributable. There is no question of seepage involved in 
tins case, but there is a good supply of irrigating water and a small 
ditch flowing just west of the orchard. The prevalence of this 
trouble throughout this orchard and the intensity of the burning on 
a few trees were matters of surprise to me. I had known of the 
