104 BOARD OF AGRICULTURE. [Pub. Doc. 



tobacco ofrowers, should also be mentioned. Anv of the 

 above materials may sometimes be wisely used by the farmer 

 as sources of nitrogen ; and in determining which to pur- 

 chase, the price of a pound of nitrogen should be one of the 

 leadino; factors considered. The value to the farmer of a 

 pound of nitrogen in these various materials may not be the 

 same in all. If wisely used, the more available are generally 

 the more valuable ; but since the more available nitrogenous 

 fertilizers are also more lial^le to waste by leaching, this is 

 not the invariable rule. Many would prefer sulphate of 

 ammonia and dried blood to nitrate of soda, because they are 

 less subject to waste. It does not answer to make a heavy 

 application of nitrate of soda in early spring to a slow- 

 growing crop. For this reason I generally advise the use of 

 a mixture of materials. Nitrate of soda may be used alone 

 by making several small applications, but it is generally less 

 expensive to make one application of mixed materials. 

 As a means of feeding a c-rop with nitrogen I would use a 

 mixture of nitrate of soda, dried blood, fish or tankage and 

 bone meal. At present prices, however, it should be 

 remarked that nitrate of soda is one of the cheapest sources 

 of nitrogen in available form. 



Other materials furnishing nitrogen, such as horn and 

 hoof waste, wool and hair waste and leather, should be left 

 to the manufacturer. Their action is so slow that it is inad- 

 visable for the farmer to purchase them. 



Phosphokic Acid Fertilizers. 

 The more important of these, also mentioned in the prob- 

 al)le order of their availability, are superphosphates (includ- 

 ing dissolved bone-black), tankage, dry ground fish, phos- 

 phatic slag, 1)one meal, Florida phosphate. South Carolina 

 phosphate, phosphatic guanos and apatite. Cotton-seed 

 meal may also be mentioned as of considerable importance in 

 some localities. Tankage, fish, bone meal and cotton-seed 

 meal, it will be remembered, have been mentioned as also 

 furnishing nitrogen. The others in our list furnish only 

 phosphoric acid. In selecting from this list, the availability 

 and the cost of a pound of phosphoric acid should l)e the 

 points considered. In general, the more availaljle the higher 



