170 Fertilisers [pt. hi 



Peat moss is not generally nsed on farms as sufficient 

 straw is usually available, but in city stables it is often 

 preferred by reason of its higher absorbent power. Peat 

 moss manure maj'^ be expected to contain more ammonia 

 than ordinary manure, but on tlie other hand the peat 

 moss does not itself contribute as much to the manure as 

 straw, being poorer in potash and phosphoric acid. Fur- 

 ther it does not so readily decompose and is therefore 

 less useful on light soils. 



The manure as made. Knomng the weight and com- 

 position of the food and litter and deducting the food 

 constituents retained by the animal, it is easy to calcu- 

 late the amount of fertilising materials in any particular 

 lot of farmyard manure. Experiments by Voelcker, 

 Wood and the writer show that the calculation does not 

 come out right, the quantity of nitrogen found in the 

 manure being usually about 15 per cent, less than was 

 anticipated. The loss does not take place in the animal : 

 physiological experiments have shown that the whole 

 of the nitrogen of the food is excreted in the urine and 

 faeces: the loss goes on through the action of micro- 

 organisms wMle the manure is in the stall and before it 

 is removed. After making this allowance we can find the 

 total quantity of fertilising material in the heap. The 

 amount per ton, however, depends on the amount of 

 water present and tins varies with the different animals ; 

 sheep and horses giving more concentrated urine and 

 faeces than cattle and pigs. 



In view of the great variability in the quantity and 

 composition of the litter and of the food it is obvious 

 that no very definite figures can be given for the com- 

 position of farmyard manure. Numerous analj^ses have 

 been made; a few are given in Table X. 



