248 



Feeds and Feeding. 



The source of the fertility in manures is well illustrated by the 

 following table from Hebert:^ 



Location of nitrogen, phosphoric acid, and potash in excrement. 



We learn that the virine of the horse contains 1.52 per ct. of ni- 

 trogen and the solid excrement 0.55 per ct., or only one-third as 

 much. The reverse holds true for the phosphoric acid, for only a 

 trace of this appears in the urine and nearly all in the solid excre- 

 ment. Of the potash, 0.9 per ct. is found in the urine and only 0.1 

 per ct. in the solid excrement. 



The fertilizing constituents which pass off with the solid excre- 

 ment are largely insoluble and to this extent not directly available 

 to plants when applied in manures. On the other hand, the con- 

 stituents in urine are in soluble form and directly available to the 

 plant. 



384. Fertilizing matter produced yearly. — According to Roberts,^ 

 the quantity and value of manure from farm animals maintained 

 under good conditions is substantially as follows: 



Amount and value of fertilizing constituents voided yearly hy farm 

 animals. 



Horse (Hebert) 



Cow 



Sheep (Muntz and Girard) 

 Pig (Boussingault) 



Value per year 

 Dollars 

 27.05 

 37.48 



2.44 



3.31 



The last column of the table, showing the commercial value of the 

 manure of farm animals, is obtained by giving to the several fer- 

 tilizing constituents the price per pound they at present command 

 in commercial fertilizers, viz. nitrogen 18 cents, phosphoric acid 5 

 cents, and potash 5 cents per lb. 



^ Expt. Sta. Eecord, Vol. 5 ; also Fertility of the Land, Eoberts, p. 180. 

 * The Fertility of the Land. 



