THE FERMENTATIONS OF MANURE Sr 
striking testimony to the value of compacting. If, further, the 
manure be stored in cemented pits,that will prevent loss by drain- 
ing, the greater part of the ordinary losses may be prevented. In 
thus storing the manure, it should be kept moist by the use of 
liquid manure, but not allowed to become water-soaked. The 
largest portion of the liquid manure, however, should not be kept 
in liquid form but should be absorbed by bedding (‘‘litter’’) 
or by soil, as this prevents much loss of ammonia. If plenty of 
litter is available, it is good practice to spread manure and litter 
on the floor of a manure shed and let ihe cows trample it down by 
giving them their exercise in the shed when the weather prevents 
their going to pasture. 
Thus the best methods of protecting manure from loss of nitro- 
gen are: (x) The use of litter to absorb the liquid manure. (2) 
Compacting. (3) The regulation of the amount of moisture. (4) 
Storing on an impervious floor, to prevent loss of liquid manure. 
(5) Mixing with phosphates to ix the ammonia. 
Constructive Fermentations.—In order that the manure may 
become plant food, the end-products of decomposition must be 
built up into the form of nitrates by nitrification. Exactly when 
nitrification begins is a little uncertain. If the nitrifiers were as 
susceptible to the presence of organic matter in manure as they are 
in laboratory media, it could be asserted that nitrification did not 
begin until the decomposition bacteria had used up the organic 
matter. Itis known, however, that they may be active in manure 
while there is still much organic matter left. 
When the nitrifying processes do begin, they complete the 
ripening of the manure. They oxidize the nitrogen compounds 
which are left, the ammonia salts becoming first changed to nitrites 
and then to nitrates. As this process continues the manure is 
more and more filled with nitrates and therefore becomes a better 
and better food for plants. At last when the process is ended and 
the manure is fully ripened, enough of nitrogen is converted into 
nitrates to furnish a most valuable supply of food for vegetation. 
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