AGRICULTURAL ECONOMICS 



largest possible addition to the farmer's total net 

 profit. 



One factor ever to be kept in mind in counting 

 the profits of the live stock industry is the value, 

 as fertilizer, of the manure, which is a very im- 

 portant by-product of this industry. This ele- 

 ment is usually underestimated in a new country, 

 but in the older countries where commercial fer- 

 tilizers have long been necessary if the farmer 

 would secure the largest net profit in the produc- 

 tion of field crops, full value must be given to this 

 by-product. 



Professor Charles F. Curtiss, of the Iowa Agri- 

 cultural College, says: 1 "Maintenance of fer- 

 tility is secured by rotation of crops, by chemical 

 fertilizers, and by physical and bacteriological 

 methods ; but . by none of these has the virgin 

 strength of the soil been maintained over long 

 periods except as plant production has been asso- 

 ciated with animal husbandry. By selling dairy 

 products in the form of butter and cheese and 

 restoring the by-products by feeding the skim 

 milk, buttermilk and whey we take from the soil 

 but one-tenth of fertility lost by a grain crop. . . . 

 If fertilizing material must be bought for the 

 farm, it can, under all ordinary conditions, be 

 bought in vastly cheaper form as feed stuffs and 

 utilized as such, and the residue applied to the 



1 From a paper entitled, "Economic Functions of Live 

 Stock," read before the Economic Section of the A. A. A. S., 

 St. Louis, December, 1903. 



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