The: Ammonifying Efficiency of Certain Colorado Soils. 5 
standard solutions to determine the amount of ammonia formed dur¬ 
ing the experiment. 
The various nitrogenous substances employed to furnish the pro- 
teid nitrogen contained total nitrogen as follows: 
Cottonseed meal.7.8463 per cent, total nitrogen 
Dried blood.,...13.0503 per cent, total nitrogen 
Alfalfa meal. 2.5053 per cent, total nitrogen 
Flaxseed meal. 3.7507 per cent, total nitrogen 
lo obtain 100 m. g. of total nitrogen from these materials the fol¬ 
lowing amounts were taken: 
Cottonseed meal. 
Dried blood. 
grams 
Alfalfa 
meal. 
1 d 111 0 
Flaxseed 
meal. 
£ 51 dill 0 
grams 
The ammonia originally present in the soils was determined, and, 
although of negligible quantity in many cases, corrections have been 
made for it in the results of the analyses. The ammonia found is * 
given in Table No. 3, page 19. 
HISTORY, CHARACTER AND AMMONIFYING EFFI¬ 
CIENCY OF THE SOILS UNDER STUDY. 
Sample No. i. 
The orchard from which this sample was obtained was first 
brought to my attention in the summer of 1910 because of the ap¬ 
pearance of niter burning on some of the apple trees. This is an 
old orchard, and two of the trees were in a very serious condition 
at that time. I visited it again in the fall of 1911, when I collected 
the present sample, and both of the trees affected in 1910 were 
dead, while seven others, all Ben Davis, were in a critical state. 
The soil is a heavy, adobe clay and was moist from recent rains. 
The nitrogen fixation test in mannite solution, made one year pre¬ 
viously, gave an increase of 11.3483 m. g. of nitrogen per 100 c. c. 
of solution in thirty days. The nitrogen recovered as ammonia 
from the different organic materials in seven days was as follows: 
From cottonseed meal 46.63% ; dried blood 37.02% ; alfalfa 
meal 17*55% J flaxseed meal 3.01%. 
Sample No. 2. 
This repi esents a portion of another orchard in a heavy clay 
soil adjacent to No. 1. No losses had been incurred here as yet 
from niter, although at this time, fall 1911, six large trees were 
unquestionably affected. A young orchard to the north, wi'th al¬ 
falfa between the rows of trees, was in a very thrifty condition.. 
An adjoining orchard of possibly ten to twelve acres belonging to- 
the same owner had suffered considerable injury from niter for the past: 
three years. The land had been manured heavily, but, so far as 
