240 AGRICULTURE 



figures are based on the cost of an equal amount of com- 

 mercial fertilizer. 



It is true that not all the fertility taken from the soil by 

 farm crops can be returned by using the manure from the 

 feeding of crops, but the greater part of it can be. The 

 manurial value of different farm products, based on the 

 cost of commercial fertilizers, is shown in the following 

 table: (Farmers' Bulletin 193, U. S. Dept. of .Agriculture.) 



Value of fertilizer in ton 



Phosphoric 

 Product Nitrogen acid Potash Total 



We see from the above table that the farmer who sells 

 a ton of meadow hay loses from his farm, fertilizer that 

 would cost about five dollars if purchased in commercial 

 form. If he sells clover hay, he loses almost as much value 

 in fertilizer as his hay brings him. If he pay twenty dol- 

 lars a ton for wheat bran he gets over thirteen dollars' worth 

 of fertilizer, leaving the feeding cost only seven dollars. 



Of course it is evident that these values will not be ob- 

 tained from the feeding of farm crops unless the manure 

 is carefully saved and properly used. Not only has manure 

 great chemical value because of supplying the elements 

 needed in plant growth, but it has bacteriological value as 

 well. For manure contains an enormous number of bac- 



