MANURES AND THEIR USES. 
207 
Stable or Farmyard Manure. 
Stable or farmyard manure, regarded by gardeners and 
others as the most important fertiHser for all cultivated soils, is 
a mixture of the solid and liquid excrements of animals, with 
straw, moss, &c., used as litter. 
The quality of the manure will necessarily depend — 
(1) On the animals from which it is obtained. 
(2) On their age and condition. 
(3) On the character of their food. 
(4) On the quality of the straw employed as litter. 
(5) On its management when accumulating. 
(6) On its subsequent treatment. 
Farmyard and stable manure is distinguished by the fact that 
it contains almost all the constituents which the land requires 
in order -to grow crops. Of inorganic constituents, it possesses 
potash, soda, lime, magnesia, oxide of iron, silica, chlorine, 
phosphoric acid, and carbonic acid, all of which are found in the 
ashes of plants. 
The organic constituents are represented by various nitro- 
genous compounds, which give rise to ammonia and humic acids, 
the latter forming the chief part of the dark-coloured organic 
material or humus, from which, by means of nitrification, nitrogen 
is supplied to growing crops. 
This complexity of its composition renders stable and farm- 
yard manure an almost perfect as well as a general manure. 
Yet it is a mistake to suppose that it contains all the neces- 
sary plant-foods required for the growth of crops. The use of 
stable and farmyard manure alone, has a tendency to withdraw 
from the soil a considerable amount of phosphate of lime and 
nitrogen. For a large amount of phosphate of lime and nitrogen 
(originally in the soil, and afterwards in the food of farm animals) 
is used up in the formation of the bones, nerves, and muscles of 
the animals producing the manure. For example, the nitrogen, 
phosphates, &c., sold off a farm in the form of flesh, bones, and 
milk are obviously never returned to the soil in the excreta of 
the horses, cows, or other animals. 
Therefore it becomes a matter of the utmost importance that 
certain other fertilising substances besides that produced in 
stables and farmyards must be put into the soil if our gardens 
are to remain fertile. 
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