MIXING OF FERTILIZERS 



163 



fertilizers lies in the fact that the sources from which the 

 phosphorus, nitrogen, and potash are derived are then known. 

 A thorough knowledge of the relative availabilities of the 

 different sources of commercial fertilizers, and of their 

 actions under different crops, will enable the farmer to select 

 wisely materials the fertilizing values of which are known. 



113. Fertilizers may be Thoroughly Mixed on the Farm. 

 The mixing of fertilizers can be thoroughly done on any 

 farm, as has been shown by the South Carolina Experi- 

 ment Station. When practicable, an out-building with a 



H 



5 



\ 



5 



FIG. 63. Diagram showing relative composition and value of fertilizers: 

 A, low grade; B, medium grade; C, high grade. (Farmers' 

 Bulletin 457, U. S. Dept. Agr.) 



tight floor is preferable for the mixing, because the work 

 can be done when weather conditions would prevent out- 

 side work. If no tight floor is available, one may be made, 

 preferably under a shed, by taking straight-edged boards 

 about 1 inch in thickness, laying them on a level place 

 and keying them up tight. A floor 8 feet wide and 12 feet 

 long, surrounded on three sides by upright boards 12 inches 

 wide, will suffice for the mixing. 



The raw materials are generally purchased in sacks. If 

 a sufficient quantity is mixed to warrant the purchase in 

 car-load bulk shipments, it will usually be advisable to buy 



