12 
Colorado Experiment Station. 
acres of this orchard were pulled up and consigned to the wood pile, 
and the land was planted to corn. This was another case of a twenty 
year old orchard killed by niter in less than two years. ' The corn 
failed to make any growth, and much of it never came through the 
ground. The whole surface was covered with a hard, brown crust 
beneath which the soil was mealy and ashy in character. The soil 
is an elegant sandy loam, with splendid natural drainage. More 
as an experiment than anything else, this ground was planted to 
cantaloupes in 1911. Here and there a plant became established 
and succeeded fairly well, but the crop as a whole was a failure. 
This spring, 1912, the tract was planted to oats, notwithstanding the 
brown, mealy condition of the soil. The grain which is immediately 
adjacent to the irrigating furrows, where the niter appears to have 
been partially removed, seems to be making a pretty good growth, but 
that between the furrows, where the niter is still concentrated, is at 
a standstill. The ammonification results on this sample give the 
following percentages of nitrogen recovered as ammonia: 
From cottonseed meal 38.81%; dried blood 20.67%; alfalfa 
meal 7.19% ; flaxseed meal .38%. 
Sample No. 13. 
This soil is a clay loam from an alfalfa field and was selected 
from a locality where the nitrate trouble has been serious in neigh¬ 
boring orchards. Material collected from this same piece of ground 
in 1910 fixed 10.15925 m. g. of nitrogen in thirty days per 100 c. c. 
of mannite solution, so there is no question about the presence of 
Azotobacter. A chemical analysis of the soil does not show exces¬ 
sive nitrates. The alfalfa is perfectly healthlv, is making a splendid 
growth, and, so far as the eye can detect, both the crop and the soil 
are normal. The sample for ammonification was secured March 
27, 1912. The results of the test show the following percentages of 
nitrogen recovered as ammonia: 
From cottonseed meal 45.11% ; dried blood 41.15%; alfalfa 
meal 7.36%; flaxseed meal 7.71%. 
Sample No. 14. 
The next soil comes from an orchard on the edge of a mesa one 
hundred and fifty feet above the surrounding country. Ten apple trees 
had died here in 1910 with all the symptoms of niter and about fifty 
more in 1911. The soil is a clay loam in good condition of tilth with no 
evidence of any brown color due to Azotobacter or other signs indicative 
of excessive nitrates save the burning of the apple leaves. To all ap¬ 
pearances, the trouble is in the incipient stage. The ammonification 
test follows: From cottonseed meal 47.73% nitrogen was recovered 
as ammonia; dried blood 52.33%; alfalfa meal 16.56%; flaxseed 
meal 3.99%. 
Sample No 15. 
About one mile back on the mesa mentioned above, is an area 
where the high nitrates have done a great deal of damage the past two 
