516 NATURE AND PROPERTIES OF SOILS 



dergoes normal digestion. Some of the data available in this 

 respect are quoted below: 



Table CXII 



PERCENTAGE OF ORIGINAL FOOD CONSTITUENTS RECOVERED 

 IN FRESH MANURE. 



Animal 



Steers, Ohio x 



Steers, Penn. 2 



Steers, England 3 



Milking cows, Illinois 4 . 

 Milking cows, Penn. 5 . . 

 Milking cows, England 6 

 Heifers, England 7 . . . . 

 Sheep, Ohio 8 



NH, 



61.0 

 69.4 

 95.5 

 80.3 

 84.6 

 71.8 

 77.8 

 68.0 



P 2 o 5 



86.8 

 75.1 

 93.0 

 73.3. 

 70.7 

 75.0 

 78.4 

 87.0 



K 3 o 



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. 9 This means losses of about 25, 2Q, 



1 Thome, C. E., Maintenance of Fertility: Ohio Agr. Exp. Sta, Bui. 

 183, p. 200, 1907. 



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

 1903. ' 



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



4 Hopkins, C. G., Soil Fertility and Permanent Agriculture, p. 201, 

 Boston, 1910. 



6 Sweetser, W. S., The Manurial Value of the Excreta of Milch Cows; 

 Pa. State Coll., Ann. Rep., 1899-1900, j>p. 321-351. 



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



7 Wood, T. B., Losses in Making and Storing Farm Yard Manure; 

 Jour. Agr. Sci., Vol. II, pp. 207-215, 1907-08. 



8 Thorne, C. E., Maintenance of Fertility; Ohio Agr. Exp. Sta., Bui. 

 183, p. 202, 1907. * * ' 



•See Hopkins, C. G., Soil Fertility and Permanent Agriculture, p. 206; 

 Boston, 1910. * ' 



Also, Pippin, E. O., Live Stock and the Maintenance of Organic 



