New York Agricultural Experiment Station. 137 



When the nitrogen is given in the form of ammonia, first change 

 to equivalent of nitrogen (see (1) page 134) and then follow above 

 rule. 



When the potasli is given in the form of sulphate, first change to 

 equivalent of actual potash (see (11) page 134) and then follow rule. 



4. How TO Calculate Amounts of Materials to be Used in 

 Making a Home-Made Fertilizer. 



There will probably be little demand for information in regard 

 to quantities of different materials to be used in making home-made 

 fertilizers, since the subject is treated in a specific manner on pp. 

 96-114. But it will, at least, be of interest to learn how diflierent 

 materials may be put together to make up a given formula. 



Suppose that we desire to make a mixture containing 



Nitrogen 4 per cent. 



Available phosphoric acid 8 " 



Potash 10 " 



Suppose, in addition, that we have on hand for our purpose the 

 following materials : 



Nitrate of soda containing 16 per cent, of nitrogen. 



Acid phosphate containing 15 per cent, of available phosphoric 

 acid. 



Muriate of potash containing 50 per cent, of actual potash. 



How many pounds of each of these materials shall we take to 

 make one ton of a mixture having the composition given above ? 



To contain 4 per cent, of nitrogen, the ton must contain 80 

 pounds. The material which we use contains 16 pounds of nitrogen 

 in 100 pounds, and hence 500 pounds of nitrate of soda would be 

 required to furnish 80 pounds of nitrogen. 



To contain 8 per cent, of available phosphoric acid, the ton must 

 contain 160 pounds. Our material contains in 100 pounds 15 

 pounds of available phosphoric acid and hence 1067 pounds of acid 

 phosphate would be required to furnish 160 pounds of available 

 phosphoric acid. 



To contain 10 per cent, of actual potash, the ton must contain 

 200 pounds. Our muriate of potash is one-half actual potash and 

 hence 400 pounds of muriate would be required to furnish 200 

 pounds of actual potash. 



