516 NATURE AND PROPERTIES OF SOILS 



dergoes normal digestion. Some of the data available in this 

 respect are quoted below: 



Table CXII 



percentage of origikal pood constituents recovered 



in fresh manure. 



Animal 



Steers, Ohio ^ 



Steers, Penn.'-^ 



Steers, England ^ . . . . 

 Milking cows, Illinois*. 

 Milking eo'vvs, Penn. ^ . . 

 Milking cows, England *^ 

 Heifers, England ^ . . . . 

 Sheep, Ohio ^ 



NH, 



P=0, 



61.0 



86.8 



69.4 



75.1 



95.5 



93.0 



80.3 



73.3 



84.6 



70.7 



71.8 



75.0 



77.8 



78.4 



68.0 



87.0 



K.0 



82.4 

 81.2 

 98.5 

 76.0 

 91.0 

 90.0 

 86.4 

 91.5 



As might be expected, the data are quite variable, depend- 

 ing on the age, condition, individuality and class of animal, 

 and the character of the food. As a generalization and for 

 purposes of calculation, it may be considered that three- 

 fourths of the ammonia, four-fifths of the phosphorus, nine- 

 tenths of the potash, and one-half of the organic matter are 

 recovered in the manure.^ This means losses of about 25, 20, 



^ Thome, C. E., Maintenance of Fertiliiy; Ohio Agr. Exp. Sta., Bui. 

 183, p. 200, 1907. 



^Frear, W., Losses of Manure; Pa. Agr. Exp. Sta., Bui 63; Apr. 

 1903. 



^Hall, A. D., Fertilisers and Manures, p. 180; New York, 1921. 



* Hopkins, C. G.^ Soil Fertihty and Permanent Agriculture, p. 201, 

 Boston, 1910. 



''Sweetser, W. S., The Manurial Value of the Excreta of MilcJi Cows; 

 Pa. State Coll., Ann. Eep., 1899-1900, jvp. 321-351. 



*Hall, A. D,, Fertilisers and Manures, p. 180; New York, 1921. 



'^Wood, T. B., Losses in MaMng and Storing Farm Yard Manure; 

 Jour. Agr- Sci., Vol. II, pp. 207-210, 1907-08. 



*Tliorne, 0. E,, Maintenance of Fertility; Ohio Agr. Exp. Sta., Bui. 

 183, p. 202, 1907. 



*See Hopkins, 0. 0-., Soil Fertility and Permanent Agriculture, p. 206: 

 Boston, 1910.^ 



AlsOj Pippin, E. 0., Live StocTc and the Maintenance of Organic 



