SOILS AND ALKALI. 
15 
The vital question for the farmer is, What are the im¬ 
portant elements of plant food that the soil contains, and 
in what proportion ? This is best shown by a comparison 
of the analysis of average barnyard manure with the 
analysis of the soil. The average barnyard manure (Ville) 
contains : 
Water_ 
Carbon__ 
Hydrogen_ 
Oxygen_ 
Silica_ 
Chloride_ 
Sulphuric acid _ 
Oxide of iron_ 
Soda_ 
Magnesia_ 
Lime_ 
Phosphoric acid 
Potassa_ 
Nitrogen_ 
80.00 (1) 
6.80) 
.82 1(2) 
5.67 J 
4.42" 
.04 
.13 
.40 } (3) 
.24 
.56 J 
.18) 
.49 1(4) 
.41 J 
100.00 
In the above classes, the elements found in Nos. 1, 2 
and 3 are in great abundance in the atmosphere, and in 
most soils, and therefore form elements of little value as 
manures ; but the elements iu the 4th class, as you will see 
by examining the analysis, the soil contains in very lim¬ 
ited quantities, and for this reason the return of them be¬ 
comes necessary, as they are the most essential elemmts of 
plant food. Soils containing these elements in large quan¬ 
tities, other things being equal, must be the most produc¬ 
tive. In the above analyses the nitrogen ranges from .01 
to .03; the phosphoric acid from .14 to .29, the potash 
from .14 to .66. In many of the States trade values are 
agreed upon for nitrogen, phosphoric acid and potash 
in the fertilizers bought and sold, the nitrogen being 
worth about 18 cents a pound, the phosphoric acid 9 cents, 
