The Ammonifying Efficiency of Certain Colorado Soils. 21 
With cottonseed meal and dried blood, the ammonification has 
been almost twice as great in the niter soils as in the normal ones, 
while with alfalfa it has been from three to twelve times as much; 
the results from the flaxseed meal are so variable and irregular that 
any conclusions drawn from these figures would be little more than 
conjecture. 
Ammonification of Flaxseed Meal. 
In practically every culture that contained flaxseed meal, there 
was a heavy mycelial growth covering the entire substratum and 
filling the dish nearly to the cover, in some instances. This was 
especially noticeable with flaxseed meal, although occasionally a 
limited amount of a similar growth appeared in the presence of 
the alfalfa meal. W hat relation these fungi may have had to the 
relatively small omounts of ammonia recovered from the two sub¬ 
stances mentioned is an open question. On this point Lipman (if 
suggests the following: 
“Is it because substances possessing a large proportion of non- 
mtrogenous compounds fail to undergo ammonification entirely 
or is it because the ammonia produced in the course of their decom¬ 
position is rapidly changed back into protein substances? As to 
the first assumption it is hardly in accord with facts now known * * * * 
It seems more likely that some ammonia was produced out of these 
materials, but on account of the relatively large supply of carbohy¬ 
drates, molds and acid producing bacteria utilized the ammonia 
formed for the development of their body substances. In other words, 
whatever ammonia was produced, was utilized effectively for the 
development of mycelia and of bacterial cells. It seems reasonable 
to suppose, further, that the substances rich in protein favor the 
development of an alkaline reaction on account of the larger amounts 
of ammonia and ammonium carbonate formed. The alkaline .re¬ 
action favors, in its turn, the vigorous growth of the more typical 
putrefactive organisms capable of causing fairly intense cleavage 
of protein compounds.” 
Comparative Studies. 
In almost any investigation, a comparison of one’s results with 
the work of others along similar lines leads either to a confirma¬ 
tion of truths, or to the discovery of new facts. Such a compara¬ 
tive study has been made between some of our soils and those from 
other localities in the United States, and the differences in ammoni¬ 
fying efficiency brought out in this way have been most striking 
as the figures given in Table No. 6 indicate. The methods em¬ 
ployed by the different experimenters have been practically the 
sarnie, so the results should be comparable. The two points which 
stand out most prominently in the tabulation of these results are:— 
First, in degree of ammonifying efficiency, the niter soils of Colo- 
(1) Lipman, Jacob G., The Availability of Nitrogenous Materials as Measured b’ 
Ammonification. Cent. f. Bakt. Abt. II. Bd. 31, No. 1-4, p. 64, 65, 1911. 
