Manurial Value of Feeding Stuffs. 



249 



385. Formula for manure production. Heiden 1 worked out a for- 

 mula for calculating the amount of manure, both solid and liquid 

 excrements, produced by farm animals from a given quantity of 

 feed. He found that on the average for each 100 Ibs. of dry matter 

 supplied in the feed of the horse, 47.33 Ibs. reappears in the manure. 

 As fresh horse manure contains about 22.5 per ct. of dry matter, 

 100 Ibs. of dry matter in horse manure would yield: 



47. 33 Ibs. X 100 

 22.5 



210 Ibs. fresh manure. 



By similar calculations it is found that exclusive of bedding: 



For each 100 Ibs. of dry matter in the feed: 



The horse voids 210 Ibs. of fresh manure. 

 The cow voids 384 Ibs. of fresh manure. 

 The sheep voids 183 Ibs. of fresh manure. 



386. Value of manure. The figures given below 2 show the quan- 

 tity of the several fertilizing constituents in a ton of manure from 

 farm animals, and the value of the same based on the commercial 

 prices for the nitrogen, phosphoric acid, and potash contained: 



Value of manure per ton. 



1 Storer, Agriculture, 1899, Vol. II, p. 289. 



2 Adapted from Bui. 56, New York (Cornell) Expt Sta. 



