COMMERCIAL FERTILIZERS IN GENERAL 



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Mixed Fertilizers. Commercial fertilizers containing nitrogen, 

 phosphorus and potassium are called mixed fertilizers. Those 

 containing all three of the fertilizing elements are called " com- 

 plete" fertilizers. In this respect, manure is to be regarded as a 

 complete fertilizer. 



Hundreds of brands of mixed commercial fertilizers are to be 

 found on the market sold under various trade names; such as, 

 Corn and Cotton Grower, Dreadnaught Fertilizer, Prolific Crop 

 Producer, etc. These fertilizers are commonly spoken of in terms 

 of the per cents of the fertilizing constituents contained in them; 

 for example, a mixed fertilizer containing two per cent nitrogen 

 (N), twelve per cent phosphoric acid (P20 5 ) and two per cent 

 potash (K 2 O) is called a "2-12-2" fertilizer. 8 A "0-12-4" fertil- 

 izer means one containing no nitrogen (N), twelve per cent 

 phosphoric acid (P2O 5 ) and four per cent potash (K 2 O). 



The following shows the meaning of some mixed fertilizers 

 in terms of the elements: 



Use of Mixed Fertilizers. Mixed fertilizers are very generally 

 used. Applications vary from 50 to 1500 pounds and more to the 

 acre. It is better to purchase these fertilizers on the basis of what 

 they contain rather than because of their names. 



Commercial Fertilizers in General. Many erroneous ideas 

 are prevalent regarding the use of commercial fertilizers, especially 

 in sections where fertilizers are little used or practically unknown. 

 Some believe they injure the soil, and that when once used their 

 use must be continued. It is not because the "soil gets a bad 

 habit" that many farmers continue the use of fertilizeps, but be- 

 cause of profitable returns. Fertilizers sometimes fail for the 

 following reasons: The wrong kind of fertilizer may have been 

 used; it may have been applied in the wrong manner; the soil 

 may lack proper underdrainage, and there may have been a 

 deficiency of moisture. 



8 In some Southern states phosphoric acid is usually mentioned first, then 

 nitrogen and potash. A "10-4-3" fertilizer in those states means, therefore, 

 10 per cent phosphoric acid, 4 per cent nitrogen and 3 per cent potash. 



