Fertilizers for Various Special Crops 341 



unfavorable influence upon the quality of the product, 

 in order that satisfactory yields of good quality may be 

 secured. 



Form of the constituents. 



It has not been shown that one form of nitrogen is 

 superior to another under all circumstances, or in other 

 words, that one form of nitrogen as, for example, 

 ammonia, or nitrate, or any particular form of organic 

 nitrogen, vegetable or animal is superior to all others, 

 but rather that any or all of the good forms may be used 

 in a mixture, provided a sufficient abundance is present 

 to insure a maximum yield, though not so large an amount 

 in excess of the minerals as to encourage a rank, coarse 

 growth. Phosphates have been neglected because the 

 crop takes out very little, but recent tests indicate that 

 moderate use of them gives a healthier crop, a somewhat 

 larger crop and perhaps of somewhat better quality. 

 The phosphoric acid should be in available forms, and if 

 in these forms, must naturally be drawn largely from 

 superphosphates. The potash should in all cases be drawn 

 from sources free from chlorids. A fertilizer, therefore, 

 which contains the nitrogen, either in good organic forms, 

 as cotton-seed meal or blood, or a mixture of these organic 

 forms with ammonia or nitrate in not too large amounts, 

 which contains the phosphoric acid in a soluble form, and 

 potash derived from products free from chlorids, as 

 from high-grade sulfate, or from a carbonate, or from 

 cotton-hull ashes, if these are obtainable, may be re- 

 garded as well adapted for the crop. 



Amounts to qpply. 



An annual dressing which will furnish 100 pounds of 

 nitrogen, 75 of phosphoric acid and 150 of potash to the 



