56 FIRST PRINCIPLES OF AGRICULTURE. 



Care of Manures. Fermentation, causing loss, may 

 be prevented by keeping 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 a method of 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, it should be kept in 

 yards that drain to the centre, plenty of absorbent used, 

 and drainage from the roof not allowed to run in the 

 yard ; and the product should be removed to the field as 

 often as possible. 



Experiments conducted to determine the extent of the 

 loss of valuable constituents due to improper fermenta- 

 tion and to leaching have shown, that, under average 

 conditions of season, the loss from exposure for six 

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

 constituents; 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 Preservers. The loss of ammonia, both in 

 the stables and in manure pits, may also be prevented by 

 the use of land plaster, of kainit, or of superphosphate, 

 which has the power of fixing and retaining the vola- 

 tile gases. A pound a day per grown animal, sprinkled 

 around in the stable, is sufficient to attain the object. 

 The same proportion and amount may be used on the 



