122 Fertilizers 



changed to ammonia, usually in the form of a carbonate, 

 which is volatile, and escapes into the atmosphere. 



Care of manures. 



Fermentation, causing loss, may be prevented by keep- 

 ing the manure moist and well packed. The loss through 

 leaching may be stopped if the passage of water through 

 it is prevented. The best method to preserve it is to 

 make it under cover, and in pits made water-tight; by 

 such shelter and protection, the maximum amount of 

 manurial value is obtained. The soluble constituents are 

 prevented from being washed into the drain, and the loss 

 of volatile compounds is reduced to a minimum. Where 

 it is not practicable to have water-tight pits, manure 

 should be collected in yards that drain to the center, 

 plenty of absorbent used, drainage from the roof should 

 not be allowed to run into the yard, and the product 

 should be removed to the fields as often as possible. 



Experiments conducted to determine the extent of the 

 loss of valuable constituents due to improper fermentation 

 and to leaching have shown that, under average condi- 

 tions of season, the loss from exposure for six months 

 will range from one-third to one-half of the total constit- 

 uents. This loss falls upon the most active forms; the 

 constituents remaining in the manure after being sub- 

 jected to such losses are the least active and directly 

 useful. 



Manure preservatives. 



The loss of ammonia, both in the stables and in 

 manure pits, may also be prevented by the use of land 

 plaster, phosphate rock, kainit or acid phosphate, which 

 have the power of fixing and retaining the volatile gases. 



