Fertilizer Treatm ent 297 
Although there is now more total nitrogen applied to the manure 
plots than is applied to the plots receiving nitrogen in commercial 
form, the nitrogen in the manure must be converted into soluble nitrate 
while the commercial nitrogen is applied in the readily available form 
of nitrate of soda, so that the available nitrogen on these plots is 
probably comparable. 
OBJECT OF THE INVESTIGATION. 
Although a great many investigations have been conducted in a 
study of nitrification, few pertain to comparisons of the efficiency of 
different fertilizer treatments for nitrate production. The following 
points were deemed important in this study and they express the aim of 
this work. 
1. The comparison of the amount of nitrate nitrogen produced in 
the same field but with different fertilizer treatment. 
2. Correlation between amount of nitrate production and crop yield. 
3. Correlation between nitrates found in the soil under natural con- 
ditions with growing crops and amount accumulating under optimum 
conditions. 
4. Nitrifying power of a soil compared to crop growth and nitrate 
content in a fresh soil. 
5. Comparison of the effect of soil treatments on bacteria and 
molds. 
TECHNIC. 
There was no effort made to discover or try out new methods in 
this work and the technic employed was adapted to the needs and con- 
ditions of this experiment from methods already in common use in soil 
nitrate and bacteriological studies. 
The monthly sampling time varied from the twentieth to the end 
of the month, but all samples for each month were taken on the same 
day. The time chosen for taking samples was when all conditions were. 
most favorable thereby lessening the possibility of denitrification occur- 
ring during the incubation period. Sampling was done with a soil 
auger, ten borings made to a depth of ten inches were taken from 
representative parts of a plot. Judgment was exercised in taking the 
samples to make them as representative as possible of the soil of the 
plots. 
The samples were taken from the field to the laboratory and all 
work performed with the fresh samples was done immediately, thus not 
allowing time for any material bacterial action to take place before 
the tests were started. 
The soil from each plot was used for the following five tests: 
1. Fresh nitrates; 
2. Nitrates after two weeks incubation; 
3. Nitrates after two weeks incubation plus ammonium sulphate; 
4, Plate count of bacteria and molds; 
5. Moisture content of the fresh soil. 
The colorimetric method employing the phenol-di-sulphonic acid 
color reaction, as modified by Noyes (11) was used in determining the 
