514 NATURE AND PROPERTIES OF SOILS 



weight of animal is the only fair and logical basis of calcu- 

 lation. 



Table CXI 



MANURE EXCRETED BY VARIOUS FARM ANIMALS TO THE 1000 

 POUNDS LIVE WEIGHT. 



It is to be noted that these figures do not include litter, 

 which, in cases of horses and cattle, will range from 15 to 20 

 per cent, of the weight of the pure excrement. A working 

 horse would be expected to produce from 10 to 11 tons of 

 average manure a year, while a dairy cow on the same basis 

 would produce 14 or 15 tons. 



Rough calculations as to manurial production from horses 

 and cattle may be made from the food consumed by these 

 animals. 6 It is assumed that 50 per cent, of the dry matter of 

 the food appears in the excrement and that the necessary 

 bedding equals one-half of the dry matter of the excrement. 



1 Roberts, I. P., and Wing, H. H., On the Deterioration of Farmyard 

 Manure by Leaching and Fermentation; Cornell Agr. Exp. Sta., Bui. 13, 

 1889. Also, Roberts, I. P., The Production and Care of Farm Manure; 

 Cornell Agr. Exp. Sta., Bui. 27, 1891. Also, Watson, G. C, The Produc- 

 tion of Manure; Cornell Agr. Exp. Sta., Bui. 56, 1893. 



'Thorne, C. E., Farm Manures, p. 97; New York, 1914. 



'Thorne, C. E., and others, The Maintenance of Fertility; Ohio Agr. 

 Exp. Sta., Bui. 183, 1907. 



4 Watson, G. C, The Production of Manure; Cornell Agr. Exp. Sta., 

 Bui. 56, 1893. 6 



6 Van Slyke, L. L., Fertilisers and Crops, p. 294; New York, 1912. 



8 Hart, E. B., and Tottingham, W. E., General Agricultural Chemistry, 

 p. 125; Madison, Wis., 1913. 



