12 SOIL FERTILITY 



may serve some useful purpose in estimating the value of the 

 total products derived from animals. 



The Composition of Manure. — The amount of nitrogen, 

 phosphoric acid and potash in the voidings of farm animals 

 depends largely on the quantities of these three substances present 

 in the food consumed. The following table indicates as nearly 

 as can be stated the average composition of the solid and liquid 

 voidings of the four principal farm animals : 



Fertilizing Constituents in 1000 Pounds of Fresh Excrement 

 of Farm Animals ' 



In Solid Voidings 



Animal Water Nitrogen Phosphoric Acid Alkalies 



Lis. Lbs. Lis. Lis. 



Horse 700 4.95 2.99 2.40 



Cattle 840 3.24 2.07 1.49 



Swine 800 G.O 4.00 4.44 



Sheep 580 0.50 4.00 2.28 



In Urine 



Animal Water Nitrogen Phosphoric Acid Alkalies 



Lis. Lis. Lbs. Lis. 



Horses 890 12.0 14.9 



Cattle 920 9.5 .28 9.5 



Swine 975 3.0 1.27 10.0 



Sheep 865 10.8 3.0 21.1 



The alkalies include potash, lime, etc. 



The value of manure per ton has been a subject of some 

 discussion and naturally varies with the dryness of the manure 

 (Fig. 4), the feeds previously fed, the degree of decomposition, 

 and of leaching of the manure. _ A ton of well rotted manure is 

 worth more than a ton of the green stuff, but one and a half 

 to two tons of the green would be required to produce one of the 

 rotted. Based upon the chemical ingredients only, taking the 

 manure in its ordinary condition as removed from stables the 

 following table will indicate fairly closely the value per ton : 



^ Based on Table II. 



