CALCIUM CYANAMID 117 



Cottonseed may contain six to seven per cent of nitrogen. It is 

 used extensively as a source of nitrogen in the South. The nitrogen 

 in this form is not as quickly available as in dried blood. The price 

 of cottonseed meal has greatly advanced since its merits for stock 

 feed have been discovered. It is now found to be better economy 

 to use it for feeding stock and then use the manure as a fertilizer. 



Sulfate of ammonia is produced in the manufacture of coke 

 and illuminating gas. It usually contains about twenty per cent, 

 of nitrogen. The nitrogen in it is not all quickly available, as 

 that found in sodium nitrate. A part of it may be taken up directly 

 by some plants. Because of its acid nature it should be used in a 

 system of farming where lime is practiced. Use of it without lime 

 tends to make the soil sour. The cost in this form usually compares 

 favorably with that from nitrate of soda. 



'< Nitrate of soda is usually considered the very best form in 

 which to purchase nitrogen, if the grower wishes the nitrogen to 

 be immediately available. Since this salt dissolves in soil moisture 

 or rain water, it must be used by the plants or much of it may be 

 lost by leaching. For this reason it is well to make several small 

 applications at different times during the early part of the growing 

 season. Nitrate of soda is imported from Chili and other western 

 countries of South America, where it is mined from extensive beds. 

 It is usually received in American ports in the somewhat purified 

 form, containing about fifteen per cent, of nitrogen. In comparing 

 the cost of nitrogen from different sources, the market price of 

 nitrate of soda is usually taken as the standard for comparison. 



Calcium cyanamid is a new form of nitrogenous fertilizer, con- 

 taining much lime. Because of the presence of these two valuable 

 ingredients it is given various commercial names, such as ' 'lime- 

 nitrogen," or "nitrolime." It was first made in Norway and 

 Germany, but it is now made extensively in Italy, the United 

 States and elsewhere. It may be produced in any locality where 

 electric power is not too expensive. It is a dark gray powder, 

 having a composition of Ca(CN) 2 . On exposure to air or moisture, 

 or in the presence of steam it decomposes into ammonia and 

 calcium carbonate, thus 



Ca (CN) 2 + 3 H 2 0= 2 NH ? + CaC0 3 

 calcium cyanamid + water = ammonia + calcium carbonate 



It compares favorably as a fertilizer with sulfate of ammonia, 

 but is still thought to be somewhat injurious to very young plants, 

 if the above mentioned change has not all taken place. One of 



