346 
Journal of Agricultural Research 
Vol. VIII, No. 9 
TOTAL SOLUBLE SALTS IN EALLOW SOIL 
As shown in Table I and figure io, the total salt content of the fallow 
soil receiving 5 tons of manure was greater with irrigations of 10 inches 
or more than where none was applied; but with no or only 5 inches of 
water the salt content was higher where no manure was added. In 
most of the upper feet the average salts for the 5-ton-of-manure plots 
exceeded that with no manure, but the differences are in most cases 
not very striking. 
For every moisture treatment the salt content of the plots receiving 
15 tons of manure was lower than where no manure was added, but the 
difference is not marked where no water was applied. The fifth foot is 
the only depth at which the salt content of the 15-ton application ex- 
Eig. 10.—Graph showing the total soluble salts in the fall in fallow soil receiving different quantities of 
manure and irrigation water. Average of 3 years to a depth of 10 feet. 
ceeded that of no manure, and the upper feet differed more than the 
lower. 
With no water and 5 inches of water, especially with the latter, the 
total salts under the plots receiving 15 tons of manure exceeded those 
with 5 tons, but the other irrigation treatments show quite a wide margin 
(26 to 93 p. p. m.) in favor of the 5 tons of manure. With regard to 
depth, the difference in favor of the 5-ton application is mainly in the 
first 3 feet, the approach being quite gradual from a difference of 133 
p. p. m. at the first to 13 at the fourth foot. 
The average total salt content of plots receiving 30 inches of water is 
higher than for the other treatments, especially for the first and second 
foot in depth. In every foot except the fifth the 40-inch application 
resulted in a much lower salt content than did the other treatments, 
and in this exception the difference is not great. 
