6 Colorado Experiment Station. 
checking the destruction, no benefit could be observed. 
The ammonification test with this soil showed the following 
(amounts of nitrogen recovered as ammonia in seven days: 
From cottonseed meal 42.31% ; dried blood 47.04% ; alfalfa meal 
12.78% ; flaxseed meal 8.09%. 
Sample No. 3. 
Sample No. 3 is a sandy loam, and was obtained from a large 
orchard where niter burning was first observed in 1910. The 
number of trees involved was rather large, but the damage done 
up to the spring of 1912 had not been serious. This is one of the 
few tracts where the trouble is present, and yet where ft has made 
little real progress. Each succeeding year a few more trees become af¬ 
fected, but the orchard, as a whole, is holding its own. Oats had 
been sown as a shade crop when I sampled the soil in the fall of 
1911. The ammonification tests gave the following percentages 
of nitrogen recovered in seven days as ammonia: 
From cottonseed meal 25.92%; dried blood 18.03%; alfalfa 
meal 12.06% ; flaxseed meal 6.30%. In view of the small amount 
of injury and the slow rate at which it is moving, the relatively 
low ammonifying efficiency as brought out by these results is very 
interesting. Compared with the two preceding samples taken from 
orchard were dead, and the trees on the remaining acre were in 
ammonification of cottonseed meal and dried blood was less than 
half as rapid. If the same holds true of nitrification, it is easy to 
understand why the nitrates have not become excessive as yet. 
Sample No. 4. 
This soil comes from an orchard where no excessive niter had 
manifested itself previous to 1911. In driving through the coun¬ 
try, I had passed by this p’ace frequently in former years, but had 
never observed anything unusual about either the trees or the soil. 
The high nitrates had been very destructive within half a mile of 
this locality, and whole orchard tracts, embracing ten to twenty 
acres, had been wiped out. By October, 1911, two acres of this 
orchard were dead, and the trees on the remaining acre were in 
all stages of burning. The soil, a sandy loam, was very brown 1 
both in the orchard and along the ditch banks. I have not seen 
it yet this year, but I should be very much surprised to find a single 
tree alive. The results of the ammonification tests on this soil point 
again to the close relation between excessive nitrates, as measured 
by the destruction of vegetation, and the high ammonifying effi¬ 
ciency. The following percentages of nitrogen were recovered as 
ammonia from the different nitrogenous materials: 
From • cottonseed meal 44.62%; dried blood 46.93%; alfalfa 
meal 12.40% ; flaxseed meal 1.12%. 
