70 VEGETABLE GARDENING 



potash. (Dr. Edward B. Voorhees calls a mixture of this 

 composition the basic fertilizer.) The nitrogen should 

 be derived from at least two sources, say nitrate of soda, 

 and an animal product, as dried blood. To make a more 

 simple example, we will suppose that the nitrogen is to 

 t e derived from nitrate of soda, the phosphoric acid from 

 acid phosphate and the potash from muriate of potash. 

 It simplifies matters to think of percentages as pounds. 

 P'our per cent of nitrogen means four pounds in each 

 hundred pounds or 80 pounds for the ton. As nitrate of 

 soda contains about 16 per cent nitrogen, it is readily 

 seen that 500 pounds of this salt will be required to fur- 

 nish the required amount of nitrogen. We will suppose 

 that the acid phosphate is 17 per cent available, and 160 

 pounds of phosphoric acid are needed. By dividing 160 

 by .17, we learn that 941 pounds of rock phosphate are 

 required. Muriate of potash contains 50 per cent of 

 actual potash. By calculating in the same manner it is 

 ascertained that 400 pounds of this ingredient is required 

 to supply the potash. These three materials aggregate 

 1,841 pounds. To make a ton it is necessary to add some 

 foreign matter, as sand. The sand would be known as the 

 filler, which is of no value, but it increases the cost of 

 freight, drayage and application to the land. 



The home mixing of fertilizers is a very simple opera- 

 tion. Two men provided with short-handled shovels can 

 do the work rapidly upon any smooth floor. The bottom 

 of the shovels should be flat and the corners square. The 

 grower should also provide a sand screen with a j4-inch 

 mesh, not less than 3 feet wide, 5 feet long, and mounted 

 on a frame that may be propped up at any angle to the 

 floor. 



It is not convenient to mix more than half a ton at a 

 time. The various materials are weighed and spread in a 

 fiat pile, each ingredient constituting a separate layer. 

 The sand screen is placed conveniently near the pile and 



