FARM MANURE 513 



the excrement. Litter, particularly, will exert a great influ- 

 ence in this direction. Moreover, this mode of evaluation 

 must never be confused with the much more important figure 

 known as the agricultural value of a manure. The former 

 is based on composition and assumed values of doubtful char- 

 acter. The latter arises from the effect of the manure on crop 

 yield. Obviously, a rational utilization of farm manure, as 

 with any fertilizer, should strive for the highest return to 

 an increment applied. A very good comparison between 

 commercial and agricultural values may be cited from the 

 Ohio experiments 1 with manure. The manure was treated in 

 various ways and applied to maize in a three-year rotation 

 of maize, wheat, and hay. Twenty-six crops were grown. 

 The commercial evaluation is taken as 100 in every case. 



Table CX 



COMMERCIAL AND AGRICULTURAL EVALUATION OP FARM MANURE. 



291. Amount of manure produced by farm animals. — A 

 well-fed moderately worked horse will produce daily from 

 45 to 55 pounds of manure, of which 10 to 12 pounds is 

 urine. A dairy cow, having a greater food capacity, will ex- 

 crete from 70 to 90 pounds during the same period, of which 

 20 to 30 pounds is liquid. Farm animals, especially sheep 

 and swine, vary so much in size that a thousand pound 



1 Thome, C. E., and others, The Maintenance of Fertility; Ohio Agr. 

 Exp. Sta., Bui. 183, pp. 206-209, 1907. 



