CHLORIDS AND SULPHATES. Pill 
Tt will be seen that the nitrifiers and especially the nitrate bacteria 
develop quite well in solutions. It should be noted that the only 
samples that failed to produce nitrites were those taken at 6-inch, 
12-inch, and 18-inch depths from plat 220, which failed to nitrify in 
soil. (See fig.9.) This soil, however, produced nitrates quite readily. 
This suggests the possibility that the lack of nitrification in this soil 
may be due to lack of nitrite bacteria. 
CHLORIDS AND SULPHATES. 
In alkali studies it is recognized that as a rule the chlorid type is more 
injurious to ordinary farm crops than the sulphate type. Further, in 
some investigations in the soils of the arid regions it has been found 
PLATS. 
150 100 160 | 
ee a 
wy 
: 
S 
< 
x 
5 
0) 
N 
S 
2 
S 
= 
S 
N 
& 
NY 
e 
N 
PARTS PEP MILLION OF CHLORIDS AND SULPHATES 
Fic. 14.—Diagram showing the relation between the quantity of alkali and the nitrification in samples of 
soil from plats 180, 190, 170, 150, 100, 160, 110, and 120, Truckee-Carson Experiment Farm. Samples 
taken from depths of 0 to 6 inches. 
that high nitrates correlate with the sulphate type, while low nitrates 
are usually associated with the chlorid type. It was thought, there- 
fore, that it would be of interest in connection with this work to study 
the relation of chlorids and sulphates to the nitrifying power. 
In plotting these curves the different plats are arranged in such 
an order that the nitrification of ammonium sulphate by the dif- 
ferent samples, which is the index of the difference of their powers 
of nitrification, forms an ascending series. Four diagrams are pre- 
sented (figs. 14 to 17), one for each depth from which samples of soil 
were taken. Figure 14, representing the surface samples, shows no 
relation between the concentration of soluble salts and nitrifying 
power. Figures 16 and 17, representing the deeper samples, are 
211 
