i6 
Colorado Experiment Station. 
Sample No. 22. 
I his sample comes from a ninety acre orchard, where the trees 
have been dying from excessive nitrates since 1908. During the 
winter of 1911 and 1912, the manager took out approximately two 
hundred and fifty dead apple trees from one corner of the orchard 
to say nothing of those removed here and there from other parts. 
A nitrogen fixation test made on this soil two years ago gave an 
increase of 8.89635 m. g. of nitrogen per 100 c. c. mannite solution 
in thirty days. At this time, the characteristic brown stain was very 
perceptible on the irrigating furrows, and today in some parts of 
the orchard the entire surface bears this same color. The orchard 
had been seeded to oats as a shade crop when I took my first sample 
for ammonification on October 27, 1911. The grain was about knee 
high and the stand was very thin. It was raining hard at this time, 
so it was impossible to tell anything about either the brown color 
or physical condition of the soil. The soil is a sandy loam and 
was collected beside a burning tree in that section of the orchard 
which was subsequently grubbed out. The results of the ammoni¬ 
fication experiment are as follows: 
From cottonseed meal 39.89% nitrogen was recovered as 
ammonia; dried blood 31.38%; alfalfa meal 11.63%; flaxseed meal 
*• 54 %. 
Samples Nos. 23, 24, 25 and 26, 27, 28. 
The samples were all collected from the orchard described as 
No. 22 and represent two vertical sections. Two large trenches 
had been dug to ascertain the level of the ground water; one in the 
lowest part of the section from which the trees had been removed, 
and the other back in the orchard on higher ground where the trees 
were just beginning to burn. In the first hole the water plane was 
found to be four feet eight inches from the surface, while in the 
second, no water was struck at eight feet. Judging by the eye, the 
latter was in ground four to five feet higher than the former. The 
face of each trench was cut down as smooth and clean as possible 
with a shovel, and then the surface inch of this face was removed 
at the point where the sample was to be taken with a sterile spatula. 
After cutting out this surface block very carefully, the sample proper 
was taken with a second sterilized spatula. These precautions were 
taken in order to avoid the danger from surface contaminations which 
were almost certain to have been carried down with the shovel. 
In this manner, three samples were obtained from each hole at three 
different depths; namely, (1) the surface three inches; (2 ) 18th 
to 24th inches; (3) 56th to 60th inches. Samples Nos. 23, 24, and 
25 came from hole No. 1, and Nos. 26, 27, and 28 from No. 2. Nos. 
23 ar, d 26 represent the surface portions; Nos. 24 and 27, the sec¬ 
tion at 18 to 24 inches; and Nos. 25 and 28, the samples at’ 56 to 60 
inches from the respective holes. 
The soils are so unlike in physical character at the different 
