to. i 
nib 
>p-4- 
Bulletin 160 
m tr,-(' 
May, 1910 
The Agricultural Experiment Station 
OF THE 
Colorado Agricultural College 
NITRATES IN THE SOIL 
An Explanation of so-called “Black Alkali or Brown Spots 
BY 
WM. P. HEADDEN 
PUBLISHED BY THE EXPERIMENT STATION 
FORT COLLINS, COLORADO 
