The Deterioration of Manures. 
19 
er, and comparatively dry manure. It is easy to see, therefore, why 
manures under our conditions lose so much of their nitrogen. The 
bright, almost continuous sunshine and drying winds, are the two 
greatest agents tending to dissipate this valuable element of fertility. 
Another factor which is responsible for great loss of ammonia is the 
way in which our manures are cared for, viz., the practice of scraping 
the manure out of the corral into a loose pile. Admitting the air into 
the manure heap in this way both dries it out and supplies a plentiful 
amount of oxygen which gives just the right conditions for intense 
aerobic activity, especially when the cleaning of the corrals takes place 
in the summer time, as is usually the case. If the manure was com¬ 
pacted and moistened thoroughly, or put into pits and the leachings 
pumped back on the pile, as is the custom in France, the loss would be 
negligible in comparison with the good done by the slower and less 
destructive anaerobic fermentation. 
What has just been stated regarding the loss of ammonia from 
manure which has been loosely piled up is well illustrated by four sam¬ 
ples from Table II, viz., Nos. 18, 19, 20, and 21. These, manures are all 
one year old, but had been treated in different ways by the farmers 
who owned them. Number 18 was scraped into a pile the fore part of 
November, a few days before the sample was taken. Number 19 lay 
untouched in an open corral. Number 20 had been scraped into a 
pile in May, and Number 21 early in September. Samples of these 
manures were collected in November and analyzed immediately with 
the following results: 
No. 18 _,__i.68 percent free ammonia. 
Nq. 19 _1.72 percent free ammonia. 
No. 20 _0.17 percent free ammonia. 
No. 21 _0.44 percent free ammonia. 
While they are of the same age, we see that Nos. 20 and 21, 
which had been scraped into piles, had lost almost the whole of 
their free ammonia. Number 18, which had been placed in a pile a 
little while before the sample was taken, smelled very strongly of 
ammonia and was therefore losing ammonia rapidly at that time and 
probably dropped from 1.68 percent in the course of two' or three 
months down to the level to which Nos. 20 and 21 had fallen in a like 
time. Turning now to No. 19, which lay in an open corral compacted 
by the trampling of the sheep during the feeding time, we find 1.72 
percent, the same amount of free ammonia found in the fresh manures. 
The lack of air practically stopped the action of aerobic bacteria and 
anaerobic fermentation had proceeded slowly within the layer of 
manure. 
