j/,Lvr/v/-;.s. ^ 



ammonia. Even when allowed to remain in the stable 

 there is loss, but when exposed to the sun and wind in 

 small loose scattered heaps it must be very considerably 

 greater. It is practically only the valuable nitrogen which 

 suffers loss as the phosphoric acid and potash exist in more 

 stable combinations. There can be no question but that 

 the manure heaps should be made in a regular manner 

 and in larger masses than are common. There should be 

 as little surface exposed as possible, a condition which is 

 evidently not secured when scattered about indiscriminately 

 over a large area. 



Again, fermentation is largely dependent on the damp- 

 ness of the heap. In countries where the rainfall is 

 considerable this acts in two ways, first by diminishing 

 the temperature, and second by limiting the supply of air. 

 In Egypt, heaps become very dry on account of the great 

 heat and the large surface exposed. In order to prevent 

 loss it is advisable that the surface of a heap be kept in a 

 uniform state of dampness. In this way there would be 

 less loss of nitrogen. Not only so but nitrification will 

 take place more rapidly than in excessively dry heaps. 

 Finally, as already mentioned, fermentation depends on 

 the composition of the heap. The greater the proportion of 

 sheep and horse manure the more rapidly will this take 

 place ; the greater the proportion of nitrogen present the 

 more easily will it decay. 



When farm-yard manure is thus kept in heaps for a 

 considerable time a loss of weight takes place and a change 

 in its composition. The latter arises chiefly from the 

 amount of organic matter it contains, that is the excrement. 



