The Ammonifying Efficiency of Certain Colorado Soils. 
ii 
tribntion of the trouble was different in this case from what we or¬ 
dinarily find; the trees were not dying in any particular section as 
a whole, but were scattered throughout the tract, alternately good 
and bad. This was the first and most serious outbreak of niter in 
this region, which is approximately twenty miles from the orchards 
described previously. My sample was collected near a dying tree 
on October 4, 1911. The soil is a loam, inclining to clay. The re¬ 
sults from the ammonification test are as follows: 
From cottonseed meal 36.25% nitrogen recovered as ammonia; 
dried blood 32.46%; alfalfa meal 12.08%; flaxseed meal .87%. 
Sample No. 10. 
Two years ago, while looking over the orchard just described, 
I was called into a neighboring orchard to pass an opinion on some 
dying apricot trees. A glance at the soil revealed the brown stain 
of niter on the irrigating furrows, and a dozen burning apple trees 
confirmed the observation. I took a sample of this soil and found 
that it was capable of fixing 10.15725 m. g. of nitrogen per 100 c. c. 
of mannite solution in thirty days. Before leaving the orchard, I 
hunted around rather carefully to see if there were many trees in 
a serious condition, but so far as I could discover they were all con¬ 
fined to a limited section of two rows. When I went back there 
last October to get another sample of soil for my ammonification 
work, I was unable to locate either the brown soil or the affected 
trees, and a diligent search failed to reveal any more trees which 
were suffering. The sample which I secured was taken in a peach 
orchard adjacent to the block of apples referred to, and to the best 
of my knowledge represents a normal orchard soil, if the vigor of 
peach trees can be taken as any indication. It might be described 
as a loam, inclining to clay. The following results were obtained 
in the ammonification test: 
From cottonseed meal 28.33% °f the nitrogen was recovered 
as ammonia; dried blood 23.57% ; alfalfa meal 4.97% ; flaxseed 
meal 8.15%. 
Sample No. ii. 
Sample No. 11 was collected in October, 1911, from an orchard 
some distance from any that has been described previosly, and until 
this season no niter trouble had been in evidence. About thirty trees 
in all, in one corner, were dying in a typical fashion. The soil is a 
clay loam and was rather moist from a recent shower, making it 
difficult to determine the presence of any brown color. The per¬ 
centages of nitrogen recovered as ammonia in the ammonification 
test were as follows: 
From cottonseed meal 47.58%'; dried blood 51.17% ; alfalfa 
meal 13.59%; flaxseed meal 12.15%. 
Sample No. 12. 
In the spring of 1910, the trees from about four and one-half 
