370 THE PRINCIPLES OF SOIL MANAGEMENT 



depending upon the weight of the animal. Of this 

 20 to 35 pounds is likely to be urine. Even the solid 

 excreta contains a large percentage of water, and, accord- 

 ing to Boussingault, only about one-eighth of the total 

 excreta is dry matter. 



The very watery nature of cow excreta causes it to 

 require a large amount of litter. In spite of the lighten- 

 ing effect of the litter, it decomposes slowly as compared 

 with other manures. When applied alone to the soil, 

 action is slow, but it is prolonged over a considerable 

 number of years. 



The loss of ammonia in the decomposition processes 

 is much less than with horse manure. The admixture 

 of other manures adds much to the rapidity of fermen- 

 tation and to the ease of handling. 



The percentage of organic matter, nitrogen and min- 

 eral substances contained in the food of cattle that 

 appear ultimately in the excrements are as follows: 



Per cent 



Organic matter 27 



Nitrogen 42 



Mineral matter 50 



This corresponds fairly well with the percentage for 

 horse manure, and would justify the belief that the value 

 of the manure would hold about the same ratio to that 

 of the food as in the case of the horse. 



240. Swine manure. The quantity of excrement 

 voided by swine varies greatly even for mature animals, 

 the amounts per 1,000 pounds live weight varying from 

 less than 50 to more than 100 pounds per day. A more 

 concentrated ration produces less excreta, but causes 



