92 Effective Farming 



shoveled through the sand-screen and any lumps that will 

 not pass through the wire mesh should be broken and mixed 

 with the pile. The mixed fertilizer should be placed in bags 

 to facilitate storing and hauling to the fields. 



Determining the quantities of ingredients required. The 

 determination of the quantities of different ingredients neces- 

 sary to make fertilizer of a given analysis is by simple arith- 

 metic. Suppose, for example, it is desired to mix a 2-8-10 

 fertilizer, the nitrogen to come half from nitrate of soda and 

 half from dried blood, the phosphoric acid from acid-phosphate, 

 and the potash from sulfate of potash. Also, suppose the 

 nitrate of soda contains 15 per cent nitrogen, the dried blood 

 6 per cent, the acid-phosphate 16 per cent phosphoric acid, 

 the sulfate of potash 50 per cent potash. To find the number 

 of pounds proceed as in paragraph 40. 



2000 Ib. (one ton) X .02= 40 Ib. nitrogen 



2000 Ib. (one ton) X .08=160 Ib. phosphoric acid 



2000 Ib. (one ton) X .10 = 200 Ib. potash 



The nitrate of soda being 15 per cent nitrogen contains 15 

 pounds of nitrogen to the 100 pounds of nitrate of soda ; there- 

 fore to have 20 pounds of nitrogen (half the quantity required) , 

 it will require as many hundredweight of nitrate of soda as 

 20 is times 15, or 20 divided by 15, which is If. This equals 

 133f pounds, which for practical purposes may be taken as 

 134 pounds. As the dried blood is 6 per cent nitrogen it will 

 contain 6 pounds to the 100 ; therefore, to have 20 pounds of 

 nitrogen, it will require as many hundredweight of dried blood 

 as 20 is times 6, or 20 divided by 6, or 3f, which equals 333f 

 pounds, or approximately 334 pounds. The acid-phosphate, 

 as it is 16 per cent phosphoric acid, contains 16 pounds of phos- 

 phoric acid to the 100; consequently to get 160 pounds of 

 phosphoric acid requires as many hundredweight as 160 is 

 times 16, or 10, which equals 1000 pounds of phosphoric acid. 

 The sulfate of potash, as it is 50 per cent potash, contains 50 



