HANDLING MANURE 379 



The greater loss suffered by the horse manure was 

 doubtless due in part to the more rapid fermentation 

 accompanied by volatilization of ammonia, and to its 

 less compact nature making it more permeable to the 

 rain water. 



Roberts also reports an experiment in which a block 

 of undisturbed manure one foot deep, consisting of both 

 horse and cow excrement mixed with straw and solidly 

 packed by trampling of animals in a covered shed, 

 was exposed from March 31 to September 30 in a gal- 

 vanized iron pan with perforated bottom. The losses 

 were as follows: Loss 



Per cent 



Nitrogen 3.2 



Phosphoric acid 4.7 



Potash 35.0 



This shows a great saving to both kinds of manure 

 when they are mixed and tramped. The enormous 

 difference in the nitrogen lost, without a corresponding 

 difference in the loss of potash, indicates that the volatili- 

 zation of ammonia, which is greatly reduced by com- 

 pacting, is responsible for a very large share in the 

 deterioration of manure, even in a humid climate. 



251. Methods of handling. The least opportunity 

 lor deterioration of farm manure occurs when it is hauled 

 directly to the field from the stall and spread at once. 

 This is not always possible, and manure must be stored 

 on every farm for longer or shorter periods. In holding 

 manure, the two important conditions are, a sufficient, 

 but not excessive supply of moisture, and a well-com- 

 pacted mass. Water draining away from a manure heap, 



